Methoxychlor
Encyclopedia
Methoxychlor is a synthetic organochlorine used as an insecticide
.
The amount of methoxychlor in the environment
changes seasonally due to its use in farming and foresting. It does not dissolve readily in water, so it is mixed with a petroleum-based fluid and sprayed, or used as a dust. Sprayed methoxychlor settles on the ground or in aquatic ecosystems, where it can be found in sediments. Its degradation may take many months. Methoxychlor is ingested and absorbed by living organisms, and it accumulates in the food chain. Some metabolites may have unwanted side effects.
was banned in the United States
in 2003 and in the European Union
in 2002.
as observed in animal experiments. Some of the agent's metabolites have estrogen
ic effect as shown in adult and developing animals before and after birth One studied metabolite is 2,2-bis(p-hydroxyphenyl)- 1,1,1-trichloroethane (HPTE) which is considered to have reproductive toxicity in the animal model by reducing testosterone biosynthesis. Such effects adversely affect the both the male and female reproductive system
s. It is expected that this "could occur in humans" but has not been proven. While one study has linked methoxychlor to the development of leukemia
in humans, most studies in animals and humans have been negative, thus the EPA has determined that it is not classifiable as a carcinogen
. The EPA indicates that levels above the Maximum Contaminant Level
of 40 ppb "cause" central nervous depression, diarrhea, damage to liver, kidney, and heart, and - by chronic exposure - growth retardation.
Little information is available regarding effects on human pregnancy and children, but it is assumed from animals studies that methoxychlor crosses the placenta, and it has been detected in human milk Exposure to children may be different than in adults because they tend to play on the ground, further, their reproductive system may be more sensitive to the effects of methoxychlor as an endocrine disruptor
.
Food contamination may occur at low levels and it is recommended to wash all foods.. A number of hazardous waste
sites are known to contain methoxychlor.
Tradenames for methoxychlor include Chemform, Maralate, Methoxo, Methoxcide, Metox and Moxie.
Insecticide
An insecticide is a pesticide used against insects. They include ovicides and larvicides used against the eggs and larvae of insects respectively. Insecticides are used in agriculture, medicine, industry and the household. The use of insecticides is believed to be one of the major factors behind...
.
Usage
Methoxychlor is used to protect crops, ornamentals, livestock, and pets against fleas, mosquitoes, cockroaches, and other insects. It was intended to be a replacement for DDT, but has since been banned based on its acute toxicity, bioaccumulation, and endocrine disruption activity .The amount of methoxychlor in the environment
Natural environment
The natural environment encompasses all living and non-living things occurring naturally on Earth or some region thereof. It is an environment that encompasses the interaction of all living species....
changes seasonally due to its use in farming and foresting. It does not dissolve readily in water, so it is mixed with a petroleum-based fluid and sprayed, or used as a dust. Sprayed methoxychlor settles on the ground or in aquatic ecosystems, where it can be found in sediments. Its degradation may take many months. Methoxychlor is ingested and absorbed by living organisms, and it accumulates in the food chain. Some metabolites may have unwanted side effects.
Banned
The use of methoxychlor as a pesticidePesticide
Pesticides are substances or mixture of substances intended for preventing, destroying, repelling or mitigating any pest.A pesticide may be a chemical unicycle, biological agent , antimicrobial, disinfectant or device used against any pest...
was banned in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
in 2003 and in the European Union
European Union
The European Union is an economic and political union of 27 independent member states which are located primarily in Europe. The EU traces its origins from the European Coal and Steel Community and the European Economic Community , formed by six countries in 1958...
in 2002.
Human exposure
Human exposure to methoxychlor occurs via air, soil, and water, primarily in people who work with the substance or who are exposed to air, soil, or water that has been contaminated. It is unknown how quickly and efficiently the substance is absorbed by humans who have been exposed to contaminated air or via skin contact. In high doses the agent can lead to neurotoxicityNeurotoxicity
Neurotoxicity occurs when the exposure to natural or artificial toxic substances, which are called neurotoxins, alters the normal activity of the nervous system in such a way as to cause damage to nervous tissue. This can eventually disrupt or even kill neurons, key cells that transmit and process...
as observed in animal experiments. Some of the agent's metabolites have estrogen
Estrogen
Estrogens , oestrogens , or œstrogens, are a group of compounds named for their importance in the estrous cycle of humans and other animals. They are the primary female sex hormones. Natural estrogens are steroid hormones, while some synthetic ones are non-steroidal...
ic effect as shown in adult and developing animals before and after birth One studied metabolite is 2,2-bis(p-hydroxyphenyl)- 1,1,1-trichloroethane (HPTE) which is considered to have reproductive toxicity in the animal model by reducing testosterone biosynthesis. Such effects adversely affect the both the male and female reproductive system
Reproductive system
The reproductive system or genital system is a system of organs within an organism which work together for the purpose of reproduction. Many non-living substances such as fluids, hormones, and pheromones are also important accessories to the reproductive system. Unlike most organ systems, the sexes...
s. It is expected that this "could occur in humans" but has not been proven. While one study has linked methoxychlor to the development of leukemia
Leukemia
Leukemia or leukaemia is a type of cancer of the blood or bone marrow characterized by an abnormal increase of immature white blood cells called "blasts". Leukemia is a broad term covering a spectrum of diseases...
in humans, most studies in animals and humans have been negative, thus the EPA has determined that it is not classifiable as a 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...
. The EPA indicates that levels above the Maximum Contaminant Level
Maximum Contaminant Level
Maximum Contaminant Levels are standards that are set by the United States Environmental Protection Agency for drinking water quality. An MCL is the legal threshold limit on the amount of a substance that is allowed in public water systems under the Safe Drinking Water Act...
of 40 ppb "cause" central nervous depression, diarrhea, damage to liver, kidney, and heart, and - by chronic exposure - growth retardation.
Little information is available regarding effects on human pregnancy and children, but it is assumed from animals studies that methoxychlor crosses the placenta, and it has been detected in human milk Exposure to children may be different than in adults because they tend to play on the ground, further, their reproductive system may be more sensitive to the effects of methoxychlor as an endocrine disruptor
Endocrine disruptor
Endocrine disruptors are chemicals that interfere with endocrine in animals, including humans. These disruptions can cause cancerous tumors, birth defects, and other developmental disorders...
.
Food contamination may occur at low levels and it is recommended to wash all foods.. A number of hazardous waste
Hazardous waste
A hazardous waste is waste that poses substantial or potential threats to public health or the environment. According to the U.S. environmental laws hazardous wastes fall into two major categories: characteristic wastes and listed wastes.Characteristic hazardous wastes are materials that are known...
sites are known to contain methoxychlor.
Labeling
The EPA lists methoxychlor as "a persistent, bioaccumulative, and toxic (PBT) chemical by the EPA Toxics Release Inventory (TRI) program" , and as such it is a waste minimization priority chemical.Tradenames for methoxychlor include Chemform, Maralate, Methoxo, Methoxcide, Metox and Moxie.