Particulates
Encyclopedia
Particulates – also known as particulate matter (PM), suspended particulate matter (SPM), fine particles, and soot
– are tiny subdivisions of solid matter suspended in a gas or liquid. In contrast, aerosol
refers to particles and/or liquid droplets and the gas together. Sources of particulate matter can be man made or natural. Air pollution
and water pollution
can take the form of solid particulate matter, or be dissolved
. Salt is an example of a dissolved contaminant in water, while sand is generally a solid particulate.
To improve water quality
, solid particulates can be removed by water filters or settling
, and is referred to as insoluble particulate matter. Dissolved contaminants in water are often collected by distilling, allowing the water to evaporate and the contaminants to return to particle form and precipitate.
Some particulates occur naturally, originating from volcano
es, dust storm
s, forest and grassland
fires, living vegetation, and sea spray
. Human activities, such as the burning of fossil fuel
s in vehicles, power plants
and various industrial processes also generate significant amounts of particulates. Coal combustion in developing countries is the primary method for heating homes and supplying energy. Averaged over the globe, anthropogenic aerosols—those made by human activities—currently account for about 10 percent of the total amount of aerosols in our atmosphere. Increased levels of fine particles in the air are linked to health hazards such as heart disease
, altered lung function and lung cancer
.
Wind-blown mineral dust
http://grida.no/climate/ipcc_tar/wg1/168.htm#5221 tends to be made of mineral oxide
s and other material blown from the Earth's crust; this particulate is light-absorbing
. Sea salt http://grida.no/climate/ipcc_tar/wg1/169.htm#5222 is considered the second-largest contributor in the global aerosol budget, and consists mainly of sodium chloride
originated from sea spray; other constituents of atmospheric sea salt reflect the composition of sea water, and thus include magnesium
,
sulfate
, calcium
, potassium
, etc. In addition, sea spray aerosols may contain organic compounds, which influence their chemistry. Sea salt does not absorb.
Secondary particles derive from the oxidation of primary gases such as sulfur
and nitrogen oxide
s into sulfuric acid
(liquid) and nitric acid
(gaseous). The precursors for these aerosols—i.e. the gases from which they originate—may have an anthropogenic origin (from fossil fuel or coal combustion
) and a natural biogenic origin. In the presence of ammonia
, secondary aerosols often take the form of ammonium
salts; i.e. ammonium sulfate
and ammonium nitrate (both can be dry or in aqueous solution
); in the absence of ammonia, secondary compounds take an acid
ic form as sulfuric acid (liquid aerosol droplets) and nitric acid (atmospheric gas). Secondary sulfate and nitrate aerosols are strong light-scatterers
. http://grida.no/climate/ipcc_tar/wg1/172.htm#5226 This is mainly because the presence of sulfate and nitrate causes the aerosols to increase to a size that scatters light effectively.
Organic matter
(OM) can be either primary or secondary, the latter part deriving from the oxidation of VOCs
; organic material in the atmosphere may either be biogenic or anthropogenic
. Organic matter influences the atmospheric radiation
field by both scattering and absorption. Another important aerosol type is constitute of elemental carbon
(EC, also known as black carbon
, BC): this aerosol type includes strongly light-absorbing material and is thought to
yield large positive radiative forcing
. Organic matter and elemental carbon together constitute the carbonaceous
fraction of aerosols.ii http://grida.no/climate/ipcc_tar/wg1/170.htm
The chemical composition of the aerosol directly affects how it interacts with solar radiation. The chemical constituents within the aerosol change the overall refractive index
. The refractive index will determine how much light is scattered and absorbed.
The composition of particulate matter that generally causes visual effects such as smog consists of sulphur dioxide, nitrogen oxides, carbon monoxide, mineral dust, organic matter, and elemental carbon also known as black carbon or soot
. The particles are hydroscopic due to the presence of sulphur, and SO2 is converted to sulphate when high humidity and low temperatures are present. This causes the reduced visibility and yellow color.
. Diesel particulate matter is highest near the source of emission. Any info regarding DPM and the atmosphere, flora, height, and distance from major sources would be useful to determine health effects.
and terrestrial radiation
. This is quantified in the Single Scattering Albedo (SSA), the ratio of scattering alone to scattering plus absorption (extinction) of radiation by a particle. The SSA tends to unity if scattering dominates, with relatively little absorption, and decreases as absorption increases, becoming zero for infinite absorption. For example, sea-salt aerosol has an SSA of 1, as a sea-salt particle only scatters, whereas soot has an SSA of 0.23, showing that it is a major atmospheric aerosol absorber.
Particulates and Aerosols, natural and anthropogenic, can affect the climate by changing the way radiation is transmitted through the atmosphere. Direct observations of the effects of aerosols are quite limited so any attempt to estimate their global effect necessarily involves the use of computer models. The Intergovernmental Panel on Climate Change
, IPCC, says: While the radiative forcing due to greenhouse gas
es may be determined to a reasonably high degree of accuracy... the uncertainties relating to aerosol radiative forcings remain large, and rely to a large extent on the estimates from global modelling studies that are difficult to verify at the present time http://www.grida.no/climate/ipcc_tar/wg1/237.htm#678.
A graphic showing the contributions (at 2000, relative to pre-industrial) and uncertainties of various forcings is available here.
, is a cooling effect that slows the overall rate of global warming
: the IPCC's best estimate of the radiative forcing is -0.4 watt
s per square meter with a range of -0.2 to -0.8 W/m² http://www.grida.no/climate/ipcc_tar/wg1/232.htm but there are substantial uncertainties. The effect varies strongly geographically, with most cooling believed to be at and downwind of major industrial centres. Modern climate model
s addressing the attribution of recent climate change
take into account sulfate forcing, which appears to account (at least partly) for the slight drop in global temperature in the middle of the 20th century. The indirect effect (via the aerosol acting as cloud condensation nuclei, CCN
, and thereby modifying the cloud properties -albedo and lifetime-) is more uncertain but is believed to be a cooling.
, and is one of the most important absorbing aerosol species in the atmosphere. It should be distinguished from organic carbon (OC): clustered or aggregated organic molecules on their own or permeating an EC buckyball. BC from fossil fuels is estimated by the IPCC in the Fourth Assessment Report of the IPCC, TAR, to contribute a global mean radiative forcing of +0.2 W/m² (was +0.1 W/m² in the Second Assessment Report of the IPCC, SAR), with a range +0.1 to +0.4 W/m²
The large number of deaths and other health problems associated with particulate pollution was first demonstrated in the early 1970s and has been reproduced many times since. PM pollution is estimated to cause 22,000-52,000 deaths per year in the United States (from 2000) and 200,000 deaths per year in Europe
.
The effects of inhaling particulate matter that have been widely studied in humans and animals now include asthma
, lung cancer, cardiovascular issues, birth defects, and premature death
. The size of the particle is a main determinant of where in the respiratory tract the particle will come to rest when inhaled. Because of their small size, particles on the order of ~10 micrometers or less (PM10) can penetrate the deepest part of the lungs such as the bronchioles or alveoli. Larger particles are generally filtered in the nose
and throat
via cilia and mucus, but particulate matter smaller than about 10 micrometers, referred to as PM10, can settle in the bronchi and lung
s and cause health problems. The 10 micrometer size does not represent a strict boundary between respirable and non-respirable particles, but has been agreed upon for monitoring of airborne particulate matter by most regulatory agencies. Similarly, particles smaller than 2.5 micrometers, PM2.5, tend to penetrate into the gas exchange
regions of the lung, and very small particles (< 100 nanometers) may pass through the lungs to affect other organs. In particular, a study published in the Journal of the American Medical Association
indicates that PM2.5 leads to high plaque deposits in arteries, causing vascular inflammation and atherosclerosis
— a hardening of the arteries that reduces elasticity, which can lead to heart attacks and other cardiovascular problems. Researchers suggest that even short-term exposure at elevated concentrations could significantly contribute to heart disease. A study in The Lancet
concluded that traffic exhaust is the single most serious preventable cause of heart attack in the general public, the cause of 7.4% of all attacks.
The site and extent of absorption of inhaled gases and vapors are determined by their solubility in water. Absorption is also dependent upon air flow rates and the partial pressure of the gases in the inspired air. The fate of a specific contaminate is dependent upon the form in which it exists (aerosol or particulate). Inhalation also depends upon the breathing rate of the subject.
The smallest particles, less than 100 nanometers (nanoparticles), may be even more damaging to the cardiovascular system.
There is evidence that particles smaller than 100 nanometers can pass through cell membranes and migrate into other organs, including the brain. It has been suggested that particulate matter can cause similar brain damage as that found in Alzheimer
patients. Particles emitted from modern diesel engine
s (commonly referred to as Diesel Particulate Matter, or DPM) are typically in the size range of 100 nanometers (0.1 micrometer). In addition, these soot
particles also carry carcinogen
ic components like benzopyrene
s adsorbed on their surface. It is becoming increasingly clear that the legislative limits for engines, which are in terms of emitted mass, are not a proper measure of the health hazard. One particle of 10 µm diameter has approximately the same mass as 1 million particles of 100 nm diameter, but it is clearly much less hazardous, as it probably never enters the human body — and if it does, it is quickly removed. Proposals for new regulations exist in some countries, with suggestions to limit the particle surface area or the particle number.
A further complexity that is not entirely documented is how the shape of PM can affect health. Of course the dangerous feathery shape of asbestos
is widely recognised to lodge itself in the lungs with often dire consequences. Geometrically angular shapes have more surface area than rounder shapes, which in turn affects the binding capacity of the particle to other, possibly more dangerous substances.
The inhalable dust fraction is the fraction of dust that enters the nose and mouth and may be deposited anywhere in the respiratory tract. The thoracic fraction is the fraction that enters the thorax and is deposited within the lung airways and the gas-exchange regions. The respiratory fraction is what is deposited in the gas exchange regions (alveoli).
Health effects on the public are considered to be caused by climate change, which is determined to be a result of increased global temperatures. An increased burden of malnutrition, diahhreal, cardio-respiratory, and infectious diseases, in addition to an increased morbidity and mortality caused by heat waves, floods, and droughts are all thought to be public health effects of global warming
. Alarmingly, a change in the distribution of disease vectors, such as insects, is affecting public health, and thought to be initiated by climate change and air pollution.
The primary health concern caused by air pollution
, and particulate matter specifically is cardiovascular and respiratory diseases. The idea is that the earth has reached its carrying capacity
and our ecological footprint
is high across the world, and increasing. The rise of CVD as the leading cause of death in America and developing countries, and the world in general, is resulting in premature mortality that can directly be linked to air pollution
.
ejected from the eruption of Huaynaputina
probably caused the Russian famine of 1601 - 1603, leading to the deaths of two million.
Particles can affect the climate in two different ways. The "direct effect" is caused by the fact that the particles scatter and absorb solar and infrared radiation in the atmosphere. The "indirect effect" of particles are more complex and more difficult to assess. Changes in the concentration of aerosols and PM in the atmosphere cause variations in the density and size of cloud droplets. There is a set amount of water available for clouds. The water can form large droplets within the clouds, which causes precipitation (a major removal mechanism for aerosols and source of acid rain). The addition of PM into the atmosphere causes the water to condense on to the particles. This results in more, but smaller droplets in the clouds, which increases the cloud albedo. In addition to increasing the albedo, this effect tends to decrease the chance of precipitation. If precipitation is suppressed, this results in excess water remaining in the atmosphere.
The primary concern for climate effects of air pollution
is an increase in global average temperatures. Greenhouse gases produced as a result of human activity trap heat in earth's atmosphere, warming the surface. Urbanization and industrialization is the main cause of airborn particulate matter, and so it follows that air pollution is a more serious threat in densely populated areas. Electricity and heat produced by antiquated methods such as wood burning and coal combustion is still the primary method for sustaining everyday life in developing countries. Climate effects inevitably lead to health effects, which are listed above, but consist mainly of respiratory problems, cardiovascular disease, and premature death.
s in the U.S. and Europe still frequently violate the particulate standards, though urban air on these continents has become cleaner, on average, with respect to particulates over the last quarter of the 20th century. Much of the developing world, especially Asia, exceed standards by such a wide margin that even brief visits to these places may be unhealthy.
the standard for particulate matter is set nationally by the federal-provincial Canadian Council of Ministers of the Environment
(CCME). Jurisdictions (provinces) may set more stringent standards. The CCME standard for particulate matter is 30 ug/m3 (daily average, i.e. 24-hour period, 3 year average, 98th percentile).
1999/30/EC and 96/62/EC, the European Commission
has set limits for PM10 in the air:
¹ indicative value.
Suggested solutions and interventions include fuel gas desulfurization (FGD) technology and electro-static precipitators (ESP) at existing power plants, which are estimated to reduce PM concentrations 10% to 20%. Public awareness must be increased for laws and initiatives such as a 50% rebate on night time electric bills. In February 2011 the "Law on Air Pollution Reduction in the Capital City" was passed. This law includes fines for people and businesses not following limits, and tax incentives to individuals and businesses reducing air pollution. A recent list of the World's worst polluters published by Daily Finance on November 29, 2010 ranks Ulaanbaatar 5th in the world, a real tragedy considering its population only hovers around the 1.3 million mark.
During the winter months in particular, urban air obscures vision, and negatively impacts human health. The air pollution also affects the visibility in the city to such an extent that airplanes on some occasions are prevented from landing at the local airport. The annual average temperature in UB is 0 C, making it the world's coldest capital city. About 40% of the population in UB Mongolia
lives in apartments, about 80% of them supplied with central heating systems from 3 combined heat and power plants (CHP). The power plants consumed almost 3.4 million tons of coal in 2007. The pollution control technology is in poor condition.
In addition to stack emissions, another unaccounted for source in the emission inventory is the fly ash from the ponds where fly ash is disposed. Removed fly ash is sent to settling tanks where the sedimented dust is collected and sent to the ash pond. These ash ponds are continually subjected to wind erosion in the dry season.
In Ulaanbaatar, Mongolia
annual seasonal average particulate matter concentrations have been recorded as high as 279. To put this in perspective, the World Health Organization's recommended PM10 level is 20. This means that UB's PM10 levels are 14 times higher than what is recommended. This also means that UB has left Northern China's most polluted cities in its wake. Compared to such high concentrations, some cities in Northern China and South Asia also had concentrations above 200 micrograms per meter cubed up to a few years ago. The PM levels in Chinese cities are being reduced in recent years.
(EPA) sets standards for PM10 and PM2.5 concentrations in urban air. (See National Ambient Air Quality Standards
.) EPA regulates primary particulate emissions and precursors to secondary emissions (NOx
, sulfur
, and ammonia). The U.S. climate policy under the Bush administration held a goal to cut greenhouse gases by 18% between 2002 and 2012. Bush set out to encourage energy efficiency renewable energy, and agricultural practices. Under the Obama administration the U.S. climate policy sets out to change Corporate Average Fuel Economy (CAFE) standards to 35.5 miles per gallon by 2016, 4 years ahead of the 2007 schedule. In December 2009 Obama participated in the United Nation's Climate Change Conference.
On January 22, 2009, a formal information request letter was sent to manufacturers who produce or import carbon nanotubes in California, or who may export carbon nanotubes into the State. This letter constitutes the first formal implementation of the authorities placed into statute by AB 289 and is directed to manufacturers of carbon nanotubes, both industry and academia within the State, and to manufacturers outside California who export carbon nanotubes to California. This request for information must be met by the manufacturers within one year. DTSC is waiting for the upcoming January 22, 2010 deadline for responses to the data call-in.
The California Nano Industry Network and DTSC hosted a full-day symposium on November 16, 2009 in Sacramento, CA. This symposium provided an opportunity to hear from nanotechnology industry experts and discuss future regulatory considerations in California.
DTSC is expanding the Specific Chemical Information Call-in to members of the nanometal oxides, the latest information can be found on their website.
The most concentrated particulate matter pollution tends to be in densely populated metropolitan areas in developing countries. The primary cause is the burning of fossil fuels by transportation and industrial sources.
Soot
Soot is a general term that refers to impure carbon particles resulting from the incomplete combustion of a hydrocarbon. It is more properly restricted to the product of the gas-phase combustion process but is commonly extended to include the residual pyrolyzed fuel particles such as cenospheres,...
– are tiny subdivisions of solid matter suspended in a gas or liquid. In contrast, aerosol
Aerosol
Technically, an aerosol is a suspension of fine solid particles or liquid droplets in a gas. Examples are clouds, and air pollution such as smog and smoke. In general conversation, aerosol usually refers to an aerosol spray can or the output of such a can...
refers to particles and/or liquid droplets and the gas together. Sources of particulate matter can be man made or natural. Air pollution
Air pollution
Air pollution is the introduction of chemicals, particulate matter, or biological materials that cause harm or discomfort to humans or other living organisms, or cause damage to the natural environment or built environment, into the atmosphere....
and water pollution
Water pollution
Water pollution is the contamination of water bodies . Water pollution occurs when pollutants are discharged directly or indirectly into water bodies without adequate treatment to remove harmful compounds....
can take the form of solid particulate matter, or be dissolved
Dissolution (chemistry)
Dissolution is the process by which a solid, liquid or gas forms a solution in a solvent. In solids this can be explained as the breakdown of the crystal lattice into individual ions, atoms or molecules and their transport into the solvent. For liquids and gases, the molecules must be compatible...
. Salt is an example of a dissolved contaminant in water, while sand is generally a solid particulate.
To improve water quality
Water quality
Water quality is the physical, chemical and biological characteristics of water. It is a measure of the condition of water relative to the requirements of one or more biotic species and or to any human need or purpose. It is most frequently used by reference to a set of standards against which...
, solid particulates can be removed by water filters or settling
Settling
Settling is the process by which particulates settle to the bottom of a liquid and form a sediment. Particles that experience a force, either due to gravity or due to centrifugal motion will tend to move in a uniform manner in the direction exerted by that force...
, and is referred to as insoluble particulate matter. Dissolved contaminants in water are often collected by distilling, allowing the water to evaporate and the contaminants to return to particle form and precipitate.
Some particulates occur naturally, originating from volcano
Volcano
2. Bedrock3. Conduit 4. Base5. Sill6. Dike7. Layers of ash emitted by the volcano8. Flank| 9. Layers of lava emitted by the volcano10. Throat11. Parasitic cone12. Lava flow13. Vent14. Crater15...
es, dust storm
Dust storm
A dust / sand storm is a meteorological phenomenon common in arid and semi-arid regions. Dust storms arise when a gust front or other strong wind blows loose sand and dirt from a dry surface. Particles are transported by saltation and suspension, causing soil to move from one place and deposition...
s, forest and grassland
Grassland
Grasslands are areas where the vegetation is dominated by grasses and other herbaceous plants . However, sedge and rush families can also be found. Grasslands occur naturally on all continents except Antarctica...
fires, living vegetation, and sea spray
Sea spray
Sea spray is a spray of water that forms when ocean waves crash.-Make up:As a result, salt spray contains a high concentration of mineral salts, particularly chloride anions.-Effects:...
. Human activities, such as the burning of fossil fuel
Fossil fuel
Fossil fuels are fuels formed by natural processes such as anaerobic decomposition of buried dead organisms. The age of the organisms and their resulting fossil fuels is typically millions of years, and sometimes exceeds 650 million years...
s in vehicles, power plants
Power station
A power station is an industrial facility for the generation of electric energy....
and various industrial processes also generate significant amounts of particulates. Coal combustion in developing countries is the primary method for heating homes and supplying energy. Averaged over the globe, anthropogenic aerosols—those made by human activities—currently account for about 10 percent of the total amount of aerosols in our atmosphere. Increased levels of fine particles in the air are linked to health hazards such as heart disease
Heart disease
Heart disease, cardiac disease or cardiopathy is an umbrella term for a variety of diseases affecting the heart. , it is the leading cause of death in the United States, England, Canada and Wales, accounting for 25.4% of the total deaths in the United States.-Types:-Coronary heart disease:Coronary...
, altered lung function and lung cancer
Lung cancer
Lung cancer is a disease characterized by uncontrolled cell growth in tissues of the lung. If left untreated, this growth can spread beyond the lung in a process called metastasis into nearby tissue and, eventually, into other parts of the body. Most cancers that start in lung, known as primary...
.
Composition
The composition of aerosols and particles depends on their source.Wind-blown mineral dust
Mineral dust
Mineral dust is a term used to indicate atmospheric aerosols originated from the suspension of minerals constituting the soil, being composed of various oxides and carbonates. Human activities lead to 30% of the dust load in the atmosphere...
http://grida.no/climate/ipcc_tar/wg1/168.htm#5221 tends to be made of mineral oxide
Oxide
An oxide is a chemical compound that contains at least one oxygen atom in its chemical formula. Metal oxides typically contain an anion of oxygen in the oxidation state of −2....
s and other material blown from the Earth's crust; this particulate is light-absorbing
Absorption (electromagnetic radiation)
In physics, absorption of electromagnetic radiation is the way by which the energy of a photon is taken up by matter, typically the electrons of an atom. Thus, the electromagnetic energy is transformed to other forms of energy for example, to heat. The absorption of light during wave propagation is...
. Sea salt http://grida.no/climate/ipcc_tar/wg1/169.htm#5222 is considered the second-largest contributor in the global aerosol budget, and consists mainly of sodium chloride
Sodium chloride
Sodium chloride, also known as salt, common salt, table salt or halite, is an inorganic compound with the formula NaCl. Sodium chloride is the salt most responsible for the salinity of the ocean and of the extracellular fluid of many multicellular organisms...
originated from sea spray; other constituents of atmospheric sea salt reflect the composition of sea water, and thus include magnesium
Magnesium
Magnesium is a chemical element with the symbol Mg, atomic number 12, and common oxidation number +2. It is an alkaline earth metal and the eighth most abundant element in the Earth's crust and ninth in the known universe as a whole...
,
sulfate
Sulfate
In inorganic chemistry, a sulfate is a salt of sulfuric acid.-Chemical properties:...
, calcium
Calcium
Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust...
, potassium
Potassium
Potassium is the chemical element with the symbol K and atomic number 19. Elemental potassium is a soft silvery-white alkali metal that oxidizes rapidly in air and is very reactive with water, generating sufficient heat to ignite the hydrogen emitted in the reaction.Potassium and sodium are...
, etc. In addition, sea spray aerosols may contain organic compounds, which influence their chemistry. Sea salt does not absorb.
Secondary particles derive from the oxidation of primary gases such as sulfur
Sulfur oxide
Sulfur oxide refers to one or more of the following:* Lower sulfur oxides * Sulfur monoxide * Sulfur dioxide * Sulfur trioxide *Higher sulfur oxides Sulfur oxide (SOx) refers to one or more of the following:* Lower sulfur oxides (SnO, S7O2 and S6O2)* Sulfur monoxide (SO)* Sulfur dioxide (SO2)*...
and nitrogen oxide
Nitrogen oxide
Nitrogen oxide can refer to a binary compound of oxygen and nitrogen, or a mixture of such compounds:* Nitric oxide, also known as nitrogen monoxide, , nitrogen oxide* Nitrogen dioxide , nitrogen oxide...
s into sulfuric acid
Sulfuric acid
Sulfuric acid is a strong mineral acid with the molecular formula . Its historical name is oil of vitriol. Pure sulfuric acid is a highly corrosive, colorless, viscous liquid. The salts of sulfuric acid are called sulfates...
(liquid) and nitric acid
Nitric acid
Nitric acid , also known as aqua fortis and spirit of nitre, is a highly corrosive and toxic strong acid.Colorless when pure, older samples tend to acquire a yellow cast due to the accumulation of oxides of nitrogen. If the solution contains more than 86% nitric acid, it is referred to as fuming...
(gaseous). The precursors for these aerosols—i.e. the gases from which they originate—may have an anthropogenic origin (from fossil fuel or coal combustion
Combustion
Combustion or burning is the sequence of exothermic chemical reactions between a fuel and an oxidant accompanied by the production of heat and conversion of chemical species. The release of heat can result in the production of light in the form of either glowing or a flame...
) and a natural biogenic origin. In the presence of ammonia
Ammonia
Ammonia is a compound of nitrogen and hydrogen with the formula . It is a colourless gas with a characteristic pungent odour. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to food and fertilizers. Ammonia, either directly or...
, secondary aerosols often take the form of ammonium
Ammonium
The ammonium cation is a positively charged polyatomic cation with the chemical formula NH. It is formed by the protonation of ammonia...
salts; i.e. ammonium sulfate
Ammonium sulfate
Ammonium sulfate , 2SO4, is an inorganic salt with a number of commercial uses. The most common use is as a soil fertilizer. It contains 21% nitrogen as ammonium cations, and 24% sulfur as sulfate anions...
and ammonium nitrate (both can be dry or in aqueous solution
Solution
In chemistry, a solution is a homogeneous mixture composed of only one phase. In such a mixture, a solute is dissolved in another substance, known as a solvent. The solvent does the dissolving.- Types of solutions :...
); in the absence of ammonia, secondary compounds take an acid
Acid
An acid is a substance which reacts with a base. Commonly, acids can be identified as tasting sour, reacting with metals such as calcium, and bases like sodium carbonate. Aqueous acids have a pH of less than 7, where an acid of lower pH is typically stronger, and turn blue litmus paper red...
ic form as sulfuric acid (liquid aerosol droplets) and nitric acid (atmospheric gas). Secondary sulfate and nitrate aerosols are strong light-scatterers
Scattering
Scattering is a general physical process where some forms of radiation, such as light, sound, or moving particles, are forced to deviate from a straight trajectory by one or more localized non-uniformities in the medium through which they pass. In conventional use, this also includes deviation of...
. http://grida.no/climate/ipcc_tar/wg1/172.htm#5226 This is mainly because the presence of sulfate and nitrate causes the aerosols to increase to a size that scatters light effectively.
Organic matter
Organic compound
An organic compound is any member of a large class of gaseous, liquid, or solid chemical compounds whose molecules contain carbon. For historical reasons discussed below, a few types of carbon-containing compounds such as carbides, carbonates, simple oxides of carbon, and cyanides, as well as the...
(OM) can be either primary or secondary, the latter part deriving from the oxidation of VOCs
Volatile organic compound
Volatile organic compounds are organic chemicals that have a high vapor pressure at ordinary, room-temperature conditions. Their high vapor pressure results from a low boiling point, which causes large numbers of molecules to evaporate or sublimate from the liquid or solid form of the compound and...
; organic material in the atmosphere may either be biogenic or anthropogenic
Anthropogenic
Human impact on the environment or anthropogenic impact on the environment includes impacts on biophysical environments, biodiversity and other resources. The term anthropogenic designates an effect or object resulting from human activity. The term was first used in the technical sense by Russian...
. Organic matter influences the atmospheric radiation
Electromagnetic radiation
Electromagnetic radiation is a form of energy that exhibits wave-like behavior as it travels through space...
field by both scattering and absorption. Another important aerosol type is constitute of elemental carbon
Soot
Soot is a general term that refers to impure carbon particles resulting from the incomplete combustion of a hydrocarbon. It is more properly restricted to the product of the gas-phase combustion process but is commonly extended to include the residual pyrolyzed fuel particles such as cenospheres,...
(EC, also known as black carbon
Black carbon
In Climatology, black carbon or BC is a climate forcing agent formed through the incomplete combustion of fossil fuels, biofuel, and biomass, and is emitted in both anthropogenic and naturally occurring soot. It consists of pure carbon in several linked forms...
, BC): this aerosol type includes strongly light-absorbing material and is thought to
yield large positive radiative forcing
Radiative forcing
In climate science, radiative forcing is generally defined as the change in net irradiance between different layers of the atmosphere. Typically, radiative forcing is quantified at the tropopause in units of watts per square meter. A positive forcing tends to warm the system, while a negative...
. Organic matter and elemental carbon together constitute the carbonaceous
Carbonaceous
Carbonaceous is the defining attribute of a substance rich in carbon. Particularly, carbonaceous hydrocarbons are very unsaturated, high-molecular-weight hydrocarbons, having an elevated carbon:hydrogen ratio....
fraction of aerosols.ii http://grida.no/climate/ipcc_tar/wg1/170.htm
The chemical composition of the aerosol directly affects how it interacts with solar radiation. The chemical constituents within the aerosol change the overall refractive index
Refractive index
In optics the refractive index or index of refraction of a substance or medium is a measure of the speed of light in that medium. It is expressed as a ratio of the speed of light in vacuum relative to that in the considered medium....
. The refractive index will determine how much light is scattered and absorbed.
The composition of particulate matter that generally causes visual effects such as smog consists of sulphur dioxide, nitrogen oxides, carbon monoxide, mineral dust, organic matter, and elemental carbon also known as black carbon or soot
Soot
Soot is a general term that refers to impure carbon particles resulting from the incomplete combustion of a hydrocarbon. It is more properly restricted to the product of the gas-phase combustion process but is commonly extended to include the residual pyrolyzed fuel particles such as cenospheres,...
. The particles are hydroscopic due to the presence of sulphur, and SO2 is converted to sulphate when high humidity and low temperatures are present. This causes the reduced visibility and yellow color.
Removal processes
In general, the smaller and lighter a particle is, the longer it will stay in the air. Larger particles (greater than 10 micrometers in diameter) tend to settle to the ground by gravity in a matter of hours whereas the smallest particles (less than 1 micrometer) can stay in the atmosphere for weeks and are mostly removed by precipitationPrecipitation (meteorology)
In meteorology, precipitation In meteorology, precipitation In meteorology, precipitation (also known as one of the classes of hydrometeors, which are atmospheric water phenomena is any product of the condensation of atmospheric water vapor that falls under gravity. The main forms of precipitation...
. Diesel particulate matter is highest near the source of emission. Any info regarding DPM and the atmosphere, flora, height, and distance from major sources would be useful to determine health effects.
Effects of aerosols on electromagnetic radiation
All aerosols absorb, scatter, and distribute solarSunlight
Sunlight, in the broad sense, is the total frequency spectrum of electromagnetic radiation given off by the Sun. On Earth, sunlight is filtered through the Earth's atmosphere, and solar radiation is obvious as daylight when the Sun is above the horizon.When the direct solar radiation is not blocked...
and terrestrial radiation
Radiation
In physics, radiation is a process in which energetic particles or energetic waves travel through a medium or space. There are two distinct types of radiation; ionizing and non-ionizing...
. This is quantified in the Single Scattering Albedo (SSA), the ratio of scattering alone to scattering plus absorption (extinction) of radiation by a particle. The SSA tends to unity if scattering dominates, with relatively little absorption, and decreases as absorption increases, becoming zero for infinite absorption. For example, sea-salt aerosol has an SSA of 1, as a sea-salt particle only scatters, whereas soot has an SSA of 0.23, showing that it is a major atmospheric aerosol absorber.
Intergovernmental Panel on Climate Change
The Intergovernmental Panel on Climate Change is a scientific intergovernmental body which provides comprehensive assessments of current scientific, technical and socio-economic information worldwide about the risk of climate change caused by human activity, its potential environmental and...
, IPCC, says: While the radiative forcing due to greenhouse gas
Greenhouse gas
A greenhouse gas is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. The primary greenhouse gases in the Earth's atmosphere are water vapor, carbon dioxide, methane, nitrous oxide, and ozone...
es may be determined to a reasonably high degree of accuracy... the uncertainties relating to aerosol radiative forcings remain large, and rely to a large extent on the estimates from global modelling studies that are difficult to verify at the present time http://www.grida.no/climate/ipcc_tar/wg1/237.htm#678.
A graphic showing the contributions (at 2000, relative to pre-industrial) and uncertainties of various forcings is available here.
Sulfate aerosol
Sulfate aerosol has two main effects, direct and indirect. The direct effect, via albedoAlbedo
Albedo , or reflection coefficient, is the diffuse reflectivity or reflecting power of a surface. It is defined as the ratio of reflected radiation from the surface to incident radiation upon it...
, is a cooling effect that slows the overall rate of global warming
Global warming
Global warming refers to the rising average temperature of Earth's atmosphere and oceans and its projected continuation. In the last 100 years, Earth's average surface temperature increased by about with about two thirds of the increase occurring over just the last three decades...
: the IPCC's best estimate of the radiative forcing is -0.4 watt
Watt
The watt is a derived unit of power in the International System of Units , named after the Scottish engineer James Watt . The unit, defined as one joule per second, measures the rate of energy conversion.-Definition:...
s per square meter with a range of -0.2 to -0.8 W/m² http://www.grida.no/climate/ipcc_tar/wg1/232.htm but there are substantial uncertainties. The effect varies strongly geographically, with most cooling believed to be at and downwind of major industrial centres. Modern climate model
Climate model
Climate models use quantitative methods to simulate the interactions of the atmosphere, oceans, land surface, and ice. They are used for a variety of purposes from study of the dynamics of the climate system to projections of future climate...
s addressing the attribution of recent climate change
Attribution of recent climate change
Attribution of recent climate change is the effort to scientifically ascertain mechanisms responsible for recent changes observed in the Earth's climate...
take into account sulfate forcing, which appears to account (at least partly) for the slight drop in global temperature in the middle of the 20th century. The indirect effect (via the aerosol acting as cloud condensation nuclei, CCN
Cloud condensation nuclei
Cloud condensation nuclei or CCNs are small particles typically 0.2 µm, or 1/100 th the size of a cloud droplet ) about which cloud droplets coalesce. Water requires a non-gaseous surface to make the transition from a vapour to a liquid. In the atmosphere, this surface presents itself as tiny...
, and thereby modifying the cloud properties -albedo and lifetime-) is more uncertain but is believed to be a cooling.
Black carbon
Black carbon (BC), or carbon black, or elemental carbon (EC), often called soot, is composed of pure carbon clusters, skeleton balls and buckyballsFullerene
A fullerene is any molecule composed entirely of carbon, in the form of a hollow sphere, ellipsoid, or tube. Spherical fullerenes are also called buckyballs, and they resemble the balls used in association football. Cylindrical ones are called carbon nanotubes or buckytubes...
, and is one of the most important absorbing aerosol species in the atmosphere. It should be distinguished from organic carbon (OC): clustered or aggregated organic molecules on their own or permeating an EC buckyball. BC from fossil fuels is estimated by the IPCC in the Fourth Assessment Report of the IPCC, TAR, to contribute a global mean radiative forcing of +0.2 W/m² (was +0.1 W/m² in the Second Assessment Report of the IPCC, SAR), with a range +0.1 to +0.4 W/m²
Health effects
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
.
The effects of inhaling particulate matter that have been widely studied in humans and animals now include asthma
Asthma
Asthma is the common chronic inflammatory disease of the airways characterized by variable and recurring symptoms, reversible airflow obstruction, and bronchospasm. Symptoms include wheezing, coughing, chest tightness, and shortness of breath...
, lung cancer, cardiovascular issues, birth defects, and premature death
Death
Death is the permanent termination of the biological functions that sustain a living organism. Phenomena which commonly bring about death include old age, predation, malnutrition, disease, and accidents or trauma resulting in terminal injury....
. The size of the particle is a main determinant of where in the respiratory tract the particle will come to rest when inhaled. Because of their small size, particles on the order of ~10 micrometers or less (PM10) can penetrate the deepest part of the lungs such as the bronchioles or alveoli. Larger particles are generally filtered in the nose
Human nose
The visible part of the human nose is the protruding part of the face that bears the nostrils. The shape of the nose is determined by the ethmoid bone and the nasal septum, which consists mostly of cartilage and which separates the nostrils...
and throat
Throat
In vertebrate anatomy, the throat is the anterior part of the neck, in front of the vertebral column. It consists of the pharynx and larynx...
via cilia and mucus, but particulate matter smaller than about 10 micrometers, referred to as PM10, can settle in the bronchi and lung
Lung
The lung is the essential respiration organ in many air-breathing animals, including most tetrapods, a few fish and a few snails. In mammals and the more complex life forms, the two lungs are located near the backbone on either side of the heart...
s and cause health problems. The 10 micrometer size does not represent a strict boundary between respirable and non-respirable particles, but has been agreed upon for monitoring of airborne particulate matter by most regulatory agencies. Similarly, particles smaller than 2.5 micrometers, PM2.5, tend to penetrate into the gas exchange
Gas exchange
Gas exchange is a process in biology where gases contained in an organism and atmosphere transfer or exchange. In human gas-exchange, gases contained in the blood of human bodies exchange with gases contained in the atmosphere. Human gas-exchange occurs in the lungs...
regions of the lung, and very small particles (< 100 nanometers) may pass through the lungs to affect other organs. In particular, a study published in the Journal of the American Medical Association
Journal of the American Medical Association
The Journal of the American Medical Association is a weekly, peer-reviewed, medical journal, published by the American Medical Association. Beginning in July 2011, the editor in chief will be Howard C. Bauchner, vice chairman of pediatrics at Boston University’s School of Medicine, replacing ...
indicates that PM2.5 leads to high plaque deposits in arteries, causing vascular inflammation and atherosclerosis
Atherosclerosis
Atherosclerosis is a condition in which an artery wall thickens as a result of the accumulation of fatty materials such as cholesterol...
— a hardening of the arteries that reduces elasticity, which can lead to heart attacks and other cardiovascular problems. Researchers suggest that even short-term exposure at elevated concentrations could significantly contribute to heart disease. A study in The Lancet
The Lancet
The Lancet is a weekly peer-reviewed general medical journal. It is one of the world's best known, oldest, and most respected general medical journals...
concluded that traffic exhaust is the single most serious preventable cause of heart attack in the general public, the cause of 7.4% of all attacks.
The site and extent of absorption of inhaled gases and vapors are determined by their solubility in water. Absorption is also dependent upon air flow rates and the partial pressure of the gases in the inspired air. The fate of a specific contaminate is dependent upon the form in which it exists (aerosol or particulate). Inhalation also depends upon the breathing rate of the subject.
The smallest particles, less than 100 nanometers (nanoparticles), may be even more damaging to the cardiovascular system.
There is evidence that particles smaller than 100 nanometers can pass through cell membranes and migrate into other organs, including the brain. It has been suggested that particulate matter can cause similar brain damage as that found in Alzheimer
Alzheimer's disease
Alzheimer's disease also known in medical literature as Alzheimer disease is the most common form of dementia. There is no cure for the disease, which worsens as it progresses, and eventually leads to death...
patients. Particles emitted from modern diesel engine
Diesel engine
A diesel engine is an internal combustion engine that uses the heat of compression to initiate ignition to burn the fuel, which is injected into the combustion chamber...
s (commonly referred to as Diesel Particulate Matter, or DPM) are typically in the size range of 100 nanometers (0.1 micrometer). In addition, these soot
Soot
Soot is a general term that refers to impure carbon particles resulting from the incomplete combustion of a hydrocarbon. It is more properly restricted to the product of the gas-phase combustion process but is commonly extended to include the residual pyrolyzed fuel particles such as cenospheres,...
particles also carry carcinogen
Carcinogen
A carcinogen is any substance, radionuclide, or radiation that is an agent directly involved in causing cancer. This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes...
ic components like benzopyrene
Benzopyrene
Benzo[a]pyrene, C20H12, is a five-ring polycyclic aromatic hydrocarbon whose metabolites are mutagenic and highly carcinogenic. Benzo[a]pyrene is listed as a Group 1 carcinogen by the IARC. It belongs to a class of polycyclic aromatic compounds known as benzopyrenes, which consist of a benzene...
s adsorbed on their surface. It is becoming increasingly clear that the legislative limits for engines, which are in terms of emitted mass, are not a proper measure of the health hazard. One particle of 10 µm diameter has approximately the same mass as 1 million particles of 100 nm diameter, but it is clearly much less hazardous, as it probably never enters the human body — and if it does, it is quickly removed. Proposals for new regulations exist in some countries, with suggestions to limit the particle surface area or the particle number.
A further complexity that is not entirely documented is how the shape of PM can affect health. Of course the dangerous feathery shape of asbestos
Asbestos
Asbestos is a set of six naturally occurring silicate minerals used commercially for their desirable physical properties. They all have in common their eponymous, asbestiform habit: long, thin fibrous crystals...
is widely recognised to lodge itself in the lungs with often dire consequences. Geometrically angular shapes have more surface area than rounder shapes, which in turn affects the binding capacity of the particle to other, possibly more dangerous substances.
The inhalable dust fraction is the fraction of dust that enters the nose and mouth and may be deposited anywhere in the respiratory tract. The thoracic fraction is the fraction that enters the thorax and is deposited within the lung airways and the gas-exchange regions. The respiratory fraction is what is deposited in the gas exchange regions (alveoli).
Public Health Effects
Researchers at the Johns Hopkins Bloomberg School of Public Health have conducted the largest nationwide study on the acute health effects of coarse particle pollution. Coarse particles are airborne pollutants that fall between 2.5 and 10 micrometers in diameter. The study, published in the May 14, 2008, edition of JAMA, found evidence of an association with hospital admissions for cardiovascular diseases but no evidence of an association with the number of hospital admissions for respiratory diseases. After taking into account fine particle levels, the association with coarse particles remained but was no longer statistically significant.Health effects on the public are considered to be caused by climate change, which is determined to be a result of increased global temperatures. An increased burden of malnutrition, diahhreal, cardio-respiratory, and infectious diseases, in addition to an increased morbidity and mortality caused by heat waves, floods, and droughts are all thought to be public health effects of global warming
Global warming
Global warming refers to the rising average temperature of Earth's atmosphere and oceans and its projected continuation. In the last 100 years, Earth's average surface temperature increased by about with about two thirds of the increase occurring over just the last three decades...
. Alarmingly, a change in the distribution of disease vectors, such as insects, is affecting public health, and thought to be initiated by climate change and air pollution.
The primary health concern caused by air pollution
Air pollution
Air pollution is the introduction of chemicals, particulate matter, or biological materials that cause harm or discomfort to humans or other living organisms, or cause damage to the natural environment or built environment, into the atmosphere....
, and particulate matter specifically is cardiovascular and respiratory diseases. The idea is that the earth has reached its carrying capacity
Carrying capacity
The carrying capacity of a biological species in an environment is the maximum population size of the species that the environment can sustain indefinitely, given the food, habitat, water and other necessities available in the environment...
and our ecological footprint
Ecological footprint
The ecological footprint is a measure of human demand on the Earth's ecosystems. It is a standardized measure of demand for natural capital that may be contrasted with the planet's ecological capacity to regenerate. It represents the amount of biologically productive land and sea area necessary to...
is high across the world, and increasing. The rise of CVD as the leading cause of death in America and developing countries, and the world in general, is resulting in premature mortality that can directly be linked to air pollution
Air pollution
Air pollution is the introduction of chemicals, particulate matter, or biological materials that cause harm or discomfort to humans or other living organisms, or cause damage to the natural environment or built environment, into the atmosphere....
.
- Particulate matter studies in Bangkok Thailand indicated a 1.9% increased risk of dying from cardiovascular disease, and 1.0% risk of all disease for every 10 micrograms per cubic meter. Levels averaged 65 in 1996, 68 in 2002, and 52 in 2004. Decreasing levels may be attributed to conversions of diesel to natural gas combustion as well as improved regulations.
- The Mongolian government agency has recorded a 45% increase in the rate of respiratory illness in the past five years. Bronchial asthma, chronic obstructive pulmonary disease and interstitial pneumonia are the most common ailments treated by area hospitals. Levels of premature death, chronic bronchitis, and cardiovascular disease are increasing at a rapid rate.
Effects on vegetation
Particulate matter can clog stomatal openings of plants and interfere with photosynthesis functions. In this manner high particulate matter concentrations in the atmosphere can lead to growth stunting or mortality in some plant species.Climate effects
Climate effects can be extremely catastrophic; sulfur dioxideSulfur dioxide
Sulfur dioxide is the chemical compound with the formula . It is released by volcanoes and in various industrial processes. Since coal and petroleum often contain sulfur compounds, their combustion generates sulfur dioxide unless the sulfur compounds are removed before burning the fuel...
ejected from the eruption of Huaynaputina
Huaynaputina
Huaynaputina is a stratovolcano located in a volcanic upland in southern Peru. The volcano does not have an identifiable mountain profile, but instead has the form of a large volcanic crater. It has produced high-potassium andesite and dacite...
probably caused the Russian famine of 1601 - 1603, leading to the deaths of two million.
Particles can affect the climate in two different ways. The "direct effect" is caused by the fact that the particles scatter and absorb solar and infrared radiation in the atmosphere. The "indirect effect" of particles are more complex and more difficult to assess. Changes in the concentration of aerosols and PM in the atmosphere cause variations in the density and size of cloud droplets. There is a set amount of water available for clouds. The water can form large droplets within the clouds, which causes precipitation (a major removal mechanism for aerosols and source of acid rain). The addition of PM into the atmosphere causes the water to condense on to the particles. This results in more, but smaller droplets in the clouds, which increases the cloud albedo. In addition to increasing the albedo, this effect tends to decrease the chance of precipitation. If precipitation is suppressed, this results in excess water remaining in the atmosphere.
The primary concern for climate effects of air pollution
Air pollution
Air pollution is the introduction of chemicals, particulate matter, or biological materials that cause harm or discomfort to humans or other living organisms, or cause damage to the natural environment or built environment, into the atmosphere....
is an increase in global average temperatures. Greenhouse gases produced as a result of human activity trap heat in earth's atmosphere, warming the surface. Urbanization and industrialization is the main cause of airborn particulate matter, and so it follows that air pollution is a more serious threat in densely populated areas. Electricity and heat produced by antiquated methods such as wood burning and coal combustion is still the primary method for sustaining everyday life in developing countries. Climate effects inevitably lead to health effects, which are listed above, but consist mainly of respiratory problems, cardiovascular disease, and premature death.
Regulation
Due to the health effects of particulate matter, maximum standards have been set by various governments. Many urban areaUrban area
An urban area is characterized by higher population density and vast human features in comparison to areas surrounding it. Urban areas may be cities, towns or conurbations, but the term is not commonly extended to rural settlements such as villages and hamlets.Urban areas are created and further...
s in the U.S. and Europe still frequently violate the particulate standards, though urban air on these continents has become cleaner, on average, with respect to particulates over the last quarter of the 20th century. Much of the developing world, especially Asia, exceed standards by such a wide margin that even brief visits to these places may be unhealthy.
Canada
In CanadaCanada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
the standard for particulate matter is set nationally by the federal-provincial Canadian Council of Ministers of the Environment
Canadian Council of Ministers of the Environment
The Canadian Council of Ministers of the Environment is an inter-governmental organization in Canada with members from the federal government, ten provincial governments and three territorial governments...
(CCME). Jurisdictions (provinces) may set more stringent standards. The CCME standard for particulate matter is 30 ug/m3 (daily average, i.e. 24-hour period, 3 year average, 98th percentile).
EU legislation
In directivesEuropean Union directive
A directive is a legislative act of the European Union, which requires member states to achieve a particular result without dictating the means of achieving that result. It can be distinguished from regulations which are self-executing and do not require any implementing measures. Directives...
1999/30/EC and 96/62/EC, the European Commission
European Commission
The European Commission is the executive body of the European Union. The body is responsible for proposing legislation, implementing decisions, upholding the Union's treaties and the general day-to-day running of the Union....
has set limits for PM10 in the air:
| Phase 1 from 1 January 2005 |
Phase 2¹ from 1 January 2010 |
|
|---|---|---|
| Yearly average | 40 µg/m³ | 20 µg/m³ |
| Daily average (24-hour) allowed number of exceedences per year. |
50 µg/m³ 35 |
50 µg/m³ 7 |
¹ indicative value.
Mongolia
Mongolia's capital city Ulaanbaatar, is affected by choking air pollution caused by coal and wood burning stoves used for heating and cooking. The new market economy of the country and its very cold winter seasons have led to the formation of Ger districts, where 60% of the coldest capital city in the world's population resides. The resulting air pollution problem is characterized by very high concentrations of airborn particles, particulate matter, and by less severe sulphur dioxide and nitrogen oxide levels. Measurements carried out in UB shows that PM is by far the most serious component of the air pollution problem.Suggested solutions and interventions include fuel gas desulfurization (FGD) technology and electro-static precipitators (ESP) at existing power plants, which are estimated to reduce PM concentrations 10% to 20%. Public awareness must be increased for laws and initiatives such as a 50% rebate on night time electric bills. In February 2011 the "Law on Air Pollution Reduction in the Capital City" was passed. This law includes fines for people and businesses not following limits, and tax incentives to individuals and businesses reducing air pollution. A recent list of the World's worst polluters published by Daily Finance on November 29, 2010 ranks Ulaanbaatar 5th in the world, a real tragedy considering its population only hovers around the 1.3 million mark.
During the winter months in particular, urban air obscures vision, and negatively impacts human health. The air pollution also affects the visibility in the city to such an extent that airplanes on some occasions are prevented from landing at the local airport. The annual average temperature in UB is 0 C, making it the world's coldest capital city. About 40% of the population in UB Mongolia
Mongolia
Mongolia is a landlocked country in East and Central Asia. It is bordered by Russia to the north and China to the south, east and west. Although Mongolia does not share a border with Kazakhstan, its western-most point is only from Kazakhstan's eastern tip. Ulan Bator, the capital and largest...
lives in apartments, about 80% of them supplied with central heating systems from 3 combined heat and power plants (CHP). The power plants consumed almost 3.4 million tons of coal in 2007. The pollution control technology is in poor condition.
In addition to stack emissions, another unaccounted for source in the emission inventory is the fly ash from the ponds where fly ash is disposed. Removed fly ash is sent to settling tanks where the sedimented dust is collected and sent to the ash pond. These ash ponds are continually subjected to wind erosion in the dry season.
In Ulaanbaatar, Mongolia
Mongolia
Mongolia is a landlocked country in East and Central Asia. It is bordered by Russia to the north and China to the south, east and west. Although Mongolia does not share a border with Kazakhstan, its western-most point is only from Kazakhstan's eastern tip. Ulan Bator, the capital and largest...
annual seasonal average particulate matter concentrations have been recorded as high as 279. To put this in perspective, the World Health Organization's recommended PM10 level is 20. This means that UB's PM10 levels are 14 times higher than what is recommended. This also means that UB has left Northern China's most polluted cities in its wake. Compared to such high concentrations, some cities in Northern China and South Asia also had concentrations above 200 micrograms per meter cubed up to a few years ago. The PM levels in Chinese cities are being reduced in recent years.
United States
The United States Environmental Protection AgencyUnited States Environmental Protection Agency
The U.S. Environmental Protection Agency is an agency of the federal government of the United States charged with protecting human health and the environment, by writing and enforcing regulations based on laws passed by Congress...
(EPA) sets standards for PM10 and PM2.5 concentrations in urban air. (See National Ambient Air Quality Standards
National Ambient Air Quality Standards
The National Ambient Air Quality Standards are standards established by the United States Environmental Protection Agency under authority of the Clean Air Act that apply for outdoor air throughout the country...
.) EPA regulates primary particulate emissions and precursors to secondary emissions (NOx
NOx
NOx is a generic term for the mono-nitrogen oxides NO and NO2 . They are produced from the reaction of nitrogen and oxygen gases in the air during combustion, especially at high temperatures...
, sulfur
Sulfur
Sulfur or sulphur is the chemical element with atomic number 16. In the periodic table it is represented by the symbol S. It is an abundant, multivalent non-metal. Under normal conditions, sulfur atoms form cyclic octatomic molecules with chemical formula S8. Elemental sulfur is a bright yellow...
, and ammonia). The U.S. climate policy under the Bush administration held a goal to cut greenhouse gases by 18% between 2002 and 2012. Bush set out to encourage energy efficiency renewable energy, and agricultural practices. Under the Obama administration the U.S. climate policy sets out to change Corporate Average Fuel Economy (CAFE) standards to 35.5 miles per gallon by 2016, 4 years ahead of the 2007 schedule. In December 2009 Obama participated in the United Nation's Climate Change Conference.
California
In October 2008, the Department of Toxic Substances Control (DTSC), within the California Environmental Protection Agency, announced its intent to request information regarding analytical test methods, fate and transport in the environment, and other relevant information from manufacturers of carbon nanotubes. DTSC is exercising its authority under the California Health and Safety Code, Chapter 699, sections 57018-57020. These sections were added as a result of the adoption of Assembly Bill AB 289 (2006). They are intended to make information on the fate and transport, detection and analysis, and other information on chemicals more available. The law places the responsibility to provide this information to the Department on those who manufacture or import the chemicals.On January 22, 2009, a formal information request letter was sent to manufacturers who produce or import carbon nanotubes in California, or who may export carbon nanotubes into the State. This letter constitutes the first formal implementation of the authorities placed into statute by AB 289 and is directed to manufacturers of carbon nanotubes, both industry and academia within the State, and to manufacturers outside California who export carbon nanotubes to California. This request for information must be met by the manufacturers within one year. DTSC is waiting for the upcoming January 22, 2010 deadline for responses to the data call-in.
The California Nano Industry Network and DTSC hosted a full-day symposium on November 16, 2009 in Sacramento, CA. This symposium provided an opportunity to hear from nanotechnology industry experts and discuss future regulatory considerations in California.
DTSC is expanding the Specific Chemical Information Call-in to members of the nanometal oxides, the latest information can be found on their website.
Colorado
Key points in the Colorado Plan include reducing emission levels and solutions by sector. Agriculture, transportation, green electricity, and renewable energy research are the main concepts and goals in this plan. Political programs such as mandatory vehicle emissions testing and the prohibition of smoking indoors are actions taken by local government to create public awareness and participation in cleaner air. The location of Denver next to the Rocky Mountains and wide expanse of plains makes the metro area of Colorado's capital city a likely place for smog and visible air pollution.Affected areas
| Most Polluted World Cities by PM | |
|---|---|
| Particulate matter, μg/m3 (2004) |
City |
| 279 | Ulaanbaatar, Mongolia |
| 169 | Cairo, Egypt |
| 150 | Delhi, India |
| 128 | Kolkata, India (Calcutta) |
| 125 | Tianjin, China |
| 123 | Chongqing, China |
| 109 | Kanpur, India |
| 109 | Lucknow, India |
| 104 | Jakarta, Indonesia |
| 101 | Shenyang, China |
The most concentrated particulate matter pollution tends to be in densely populated metropolitan areas in developing countries. The primary cause is the burning of fossil fuels by transportation and industrial sources.
See also
- SootSootSoot is a general term that refers to impure carbon particles resulting from the incomplete combustion of a hydrocarbon. It is more properly restricted to the product of the gas-phase combustion process but is commonly extended to include the residual pyrolyzed fuel particles such as cenospheres,...
- Adequately wetAdequately wetThe phrase "adequately wet" is an environmental term referring to the handling of asbestos containing work, such as the demolition of older houses containing carcinogenic asbestos tiles or roof materials. Since there is no minimum threshold for a safe level of outdoor asbestos particle...
- Aerosol scienceAerosol scienceAerosol science is the rapidly expanding field of science which investigates the physical, chemical, and biological properties of aerosolized materials , which behave in ways that make them unique from even other forms of similar materials...
- Air pollutionAir pollutionAir pollution is the introduction of chemicals, particulate matter, or biological materials that cause harm or discomfort to humans or other living organisms, or cause damage to the natural environment or built environment, into the atmosphere....
- Arden Pope
- Biological warfareBiological warfareBiological warfare is the use of biological toxins or infectious agents such as bacteria, viruses, and fungi with intent to kill or incapacitate humans, animals or plants as an act of war...
- Carrying CapacityCarrying capacityThe carrying capacity of a biological species in an environment is the maximum population size of the species that the environment can sustain indefinitely, given the food, habitat, water and other necessities available in the environment...
- Clouds
- Criteria air contaminantsCriteria air contaminantsCriteria air contaminants , or criteria pollutants, are a set of air pollutants that cause smog, acid rain and other health hazards. The laws and regulations of different polities may define different sets. CACs are typically emitted from many sources in industry, mining, transportation,...
- DepositionDeposition (Aerosol physics)In aerosol physics, Deposition is the process by which aerosol particles collect or deposit themselves on solid surfaces, decreasing the concentration of the particles in the air. It can be divided into two sub-processes: dry and wet deposition. The rate of deposition, or the deposition velocity,...
- Diesel particulate matter
- DustDustDust consists of particles in the atmosphere that arise from various sources such as soil dust lifted up by wind , volcanic eruptions, and pollution...
- Ecological footprintEcological footprintThe ecological footprint is a measure of human demand on the Earth's ecosystems. It is a standardized measure of demand for natural capital that may be contrasted with the planet's ecological capacity to regenerate. It represents the amount of biologically productive land and sea area necessary to...
- FogFogFog is a collection of water droplets or ice crystals suspended in the air at or near the Earth's surface. While fog is a type of stratus cloud, the term "fog" is typically distinguished from the more generic term "cloud" in that fog is low-lying, and the moisture in the fog is often generated...
- Global dimmingGlobal dimmingGlobal dimming is the gradual reduction in the amount of global direct irradiance at the Earth's surface that was observed for several decades after the start of systematic measurements in the 1950s. The effect varies by location, but worldwide it has been estimated to be of the order of a 4%...
- Global WarmingGlobal warmingGlobal warming refers to the rising average temperature of Earth's atmosphere and oceans and its projected continuation. In the last 100 years, Earth's average surface temperature increased by about with about two thirds of the increase occurring over just the last three decades...
- MicromeriticsMicromeriticsMicromeritics is the science and technology of small particles. The knowledge and control of the size of particles is of importance in pharmacy and materials science. The size, and hence the surface area of a particle, can be related to the physical, chemical and pharmacologic properties of drugs...
- Global warmingGlobal warmingGlobal warming refers to the rising average temperature of Earth's atmosphere and oceans and its projected continuation. In the last 100 years, Earth's average surface temperature increased by about with about two thirds of the increase occurring over just the last three decades...
- Global Atmosphere WatchGlobal Atmosphere WatchThe Global Atmosphere Watch is a worldwide system established by the World Meteorological Organization a United Nations agency to monitor trends in the Earth's atmosphere...
- HazeHazeHaze is traditionally an atmospheric phenomenon where dust, smoke and other dry particles obscure the clarity of the sky. The World Meteorological Organization manual of codes includes a classification of horizontal obscuration into categories of fog, ice fog, steam fog, mist, haze, smoke, volcanic...
- Medical geologyMedical geologyMedical geology is an emerging interdisciplinary scientific field consisting of those aspects of geology as they affect human, animal and plant health.Examples include:*Lead and other heavy metal exposure resulting from dust and other particulates...
- MongoliaMongoliaMongolia is a landlocked country in East and Central Asia. It is bordered by Russia to the north and China to the south, east and west. Although Mongolia does not share a border with Kazakhstan, its western-most point is only from Kazakhstan's eastern tip. Ulan Bator, the capital and largest...
- National Ambient Air Quality StandardsNational Ambient Air Quality StandardsThe National Ambient Air Quality Standards are standards established by the United States Environmental Protection Agency under authority of the Clean Air Act that apply for outdoor air throughout the country...
(USA) - Particulate mask
- "Pea soup" fogPea soup fogPea soup, or a pea souper, is a type of visible air pollution, a thick and often yellowish smog caused by the burning of soft coal. Smog, a portmanteau of hi"smoke" and "fog", can be lethal, and even the healthy may be inconvenienced by it.-London:...
- PollutionPollutionPollution is the introduction of contaminants into a natural environment that causes instability, disorder, harm or discomfort to the ecosystem i.e. physical systems or living organisms. Pollution can take the form of chemical substances or energy, such as noise, heat or light...
- Radiological weaponRadiological weaponA radiological weapon or radiological dispersion device is any weapon that is designed to spread radioactive material with the intent to kill, and cause disruption upon a city or nation....
- RespiratorRespiratorA respirator is a device designed to protect the wearer from inhaling harmful dusts, fumes, vapors, or gases. Respirators come in a wide range of types and sizes used by the military, private industry, and the public...
- ScrubberScrubberScrubber systems are a diverse group of air pollution control devices that can be used to remove some particulates and/or gases from industrial exhaust streams. Traditionally, the term "scrubber" has referred to pollution control devices that use liquid to wash unwanted pollutants from a gas stream...
Further reading
- Article at earthobservatory.nasa.gov describing the possible influence of aerosols on the climate
- The Intergovernmental Panel on Climate Change (the principal international scientific body on climate change) chapter on atmospheric aerosols and their radiative effects
- InsideEPA.com, Study Links Air Toxics To Heart Disease In Mice Amid EPA Controversy
- Preining, Othmar and E. James Davis (eds.), "History of Aerosol Science," Österreichische Akademie der Wissenschaften, ISBN 3700129157 (pbk.)
- G Invernizzi et al., Particulate matter from tobacco versus diesel car exhaust: an educational perspective. Tobacco Control 13, S.219-221 (2004)
- JEFF CHARLTON Pandemic planning: a review of respirator and mask protection levels.
- Hinds, William C., Aerosol Technology: Properties, Behavior, and Measurement of Airborne Particles, Wiley-Interscience, ISBN 0471194107
External links
- National Pollutant Inventory — Particulate matter fact sheet
- WHO-Europe reports: Health Aspects of Air Pollution (2003) (PDF) and "Answer to follow-up questions from CAFE (2004) (PDF)
- American Association for Aerosol Research
- Particulate Air Pollution
- Aerosol Society — The Development of Aerosol Science in the United Kingdom
- Watch and read 'Dirty Little Secrets', 2006 Australian science documentary on health effects of fine particle pollution from vehicle exhausts
- Aerosol Science and Technology
- Canada-Wide Standards
- Little Green Data Book 2007, World Bank. Lists C02 and PM statistics by country.
- Air Pollution in World Cities (PM10 Concentrations)
- European Environment Agency
- Airborne Particles and their Health Effects — A trinational research network