Methoxychlor is a syntheticorganochlorideinsecticide, now obsolete. Tradenames for methoxychlor includeChemform,Maralate,Methoxo,Methoxcide,Metox, andMoxie.
Methoxychlor was used to protect crops, ornamentals, livestock, and pets against fleas, mosquitoes, cockroaches, and other insects. It was intended to be a replacement forDDT, but has since been banned for use as a pesticide based on its acute toxicity,bioaccumulation, and endocrine disruption activity.[3]
The amount of methoxychlor in theenvironment 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 detected insediments.[4] 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.
Human exposure to methoxychlor occurs via air, soil, and water,[8] 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.[8] Inanimal models, high doses can lead toneurotoxicity.[8] Some methoxychlor's metabolites haveestrogenic effects in adult and developing animals before and after birth.[8] One studied metabolite is2,2-bis(p-hydroxyphenyl)-1,1,1-trichloroethane (HPTE) which shows reproductive toxicity in an animal model by reducing testosterone biosynthesis.[9][10] Such effects adversely affect both the male and femalereproductive systems. It is expected that this "could occur in humans" but has not been proven.[8] While one study has linked methoxychlor to the development ofleukemia in humans, most studies in animals and humans have been negative, thus the EPA has determined that it is not classifiable as acarcinogen. The EPA indicates that levels above theMaximum Contaminant Level of 40 ppb "cause" central nervous depression, diarrhea, damage to liver, kidney, and heart, and - by chronic exposure - growth retardation.[3]
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[8] 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 anendocrine disruptor.[citation needed]
Food contamination may occur at low levels and it is recommended to wash all foods.[8] A number ofhazardous waste sites are known to contain methoxychlor.
Maximum pesticide residue limits for the EU/UK are set at 0.01 mg/kg for oranges and 0.01 mg/kg for apples.
