PANNA: Malathion Facts

Malathion Facts

EPA has expressed concern about children’s health risks from malathion when exposure from lawn treatments is combined with exposure from food and drinking water.

Used To Control: Insects
Top Uses: Cotton, medfly quarantine, mosquito control
Known Health Effects: Neurotoxicity, possible carcinogenity, suspected hormone disruption

Use and Exposure

Malathion is an organophosphorus insecticide used on agricultural and nonagricultural crops as well as residential applications, such as lawns and gardens. It is also used in government programs to control mosquitoes and boll weevils. EPA estimates that about 16.7 million pounds of active ingredient are used annually, mostly (11.2 million pounds) on cotton as part of the Boll Weevil Eradication Program (1). Malathion has been used recently to kill mosquitoes in efforts to control the spread of West Nile Virus. People may be exposed by eating contaminated food, drinking contaminated water, or breathing air near the manufacture or use of malathion (2). EPA states that “adult applicator exposure and toddler post-application exposure to turf treatments are of risk concern,” particularly in combination with food and drinking water exposure (1).

In California, 489,650 pounds were used in 2000. The top crops on which malathion were used were alfalfa and strawberries. Another common use in California was “regulatory purposes,” which might include the control of medflies and vector-borne diseases like West Nile Virus (3).

Health Effects

Breathing, ingesting, or touching malathion causes neurological effects stemming from the inhibition of cholinesterase, an enzyme necessary for the proper transmission of nerve impulses. Symptoms include excessive salivation and tearing, uncontrolled urination, weakness, nausea, vomiting, diarrhea, headaches, pinpoint pupils, confusion and dizziness. At higher doses, tremors, convulsions or respiratory paralysis may occur, sometimes leading to coma and death. Malathion is a possible carcinogen, and a suspected endocrine disruptor that interferes with the natural function of estrogen, androgen and thyroid hormones.

Companies That Manufacture Products Containing Malathion

Cheminova Agro A/S, Griffin LLC, Prentiss Inc., Verdant Brands Inc., AMVAC Chemical Corp., Gowan Co., Drexel Chemical Co., Platte Chemical Co. Inc., Micro-Flo Co. (2)

References

(1) United States Environmental Protection Agency, Office of Pesticide Programs. “Malathion Summary.” November 2000. Available at http://www.epa.gov/pesticides/op/malathion/summary.htm accessed 1/22/03.
(2) United States Environmental Protection Agency. “Overview of Malathion risk Assessment.” November 2000. Available at http://www.epa.gov/oppsrrd1/op/malathion/overview.htm accessed 1/27/03.
(3) Pesticide Action Network Pesticide Database. “Chemical Information about Malathion.” Available at http://www.pesticideinfo.org/PCW/Detail_Chemical.jsp?Rec_Id=PC32924 accessed 1/22/03.