Description
An organophosphate insecticide used on home and public lawns, gardens, trees and shrubs, as well as on cotton and some food crops. Malathion is also sprayed, aerially, over cities, suburbs and farmland to control mosquitoes and Mediterranean fruit flies. Some head lice treatments may also contain malathion.
Health Effects
Immediate Health Effects
- If SWALLOWED, malathion is Moderately Toxic
- If ABSORBED THROUGH SKIN, malathion is Not Available
- If INHALED (SNIFFED OR BREATHED IN), malathion is Slightly Toxic
Longterm or Delayed Health Effects
- This chemical is considered an Unclassifiable Carcinogen by the World Health Organization, the U.S. Environmental Protection Agency, or another agency.
- Neurotoxin = Can harm brain and central nervous system
- Suspected Endocrine Disruptor = May interfere with, mimic or block hormones
- Asthma Trigger
Other
- Can affect the brain and nervous system.
- Immediate effects may include nausea, dizziness, numbness, tingling sensations, pinpoint pupils, incoordination, headache, tremor, nausea, abdominal cramps, sweating, teary eyes, salivation, blurred vision, slow heartbeat, confusion.
- At very high exposures, can cause respiratory paralysis and death.
- Can cause skin rashes or irritation (redness, itchy or burning), hives or eye irritation (redness, tearing, swelling, blurred vision).
- There is some evidence that malathion can cause cancer, based upon animal studies. See “Other” section for details.
- Inorganic mercury can be corrosive and causes burns to skin, eyes, and respiratory passages.
How Exposures Occur
Absorption through the skin
- Children can be exposed by touching recently treated garden vegetables and fruits. Surfaces in homes, on playground equipment, recently treated lawns are other sources. Lawns and outdoor surfaces down-wind of farms that have sprayed malathion may also contain harmful residues. Lawns and outdoor surfaces may become contaminated when malathion is applied aerially. The U.S. EPA considers that there is a concern for toddlers who may be exposed after application to lawns or other turf areas.
Lice shampoos containing malathion can be absorbed through the scalp.
In Food
- Children may ingest traces of malathion in foods that have been treated with it. Malathion residues have been found on samples of bell peppers, celery, cherries, grapes, nectarines, peaches, pears, raspberries, spinach, and strawberries, among other foods.
Inhalation
- Children may breathe in malathion while it is being applied to nearby lawns, gardens or farms, or aerially for med-fly or mosquitoes.
Ingestion
- Children may accidently eat malathion by putting grass or soil into their mouths, or by touching contaminated surfaces and putting fingers in their mouths.
Significant Statistics
Nearly 17 million pounds of malathion are applied annually in the U.S., primarily to control boll weevils on cotton.
Overview of Malathion Risk Assessment. U.S. Environmental Protection Agency Office of Pesticide Programs, November 6, 2000. http://www.epa.gov/pesticides/op/malathion/overview.htm
10,637 cases of malathion-related illness reported to Poison Control Centers between 1985 and 1992.
Review of Malathion Incident Reports. U.S. Environmental Protection Agency Office of Prevention, Pesticides, and Toxic Substances, August 18, 1998. http://www.epa.gov/pesticides/op/malathion/incident.pdf
After malathion was sprayed aerially in several counties in Florida in 1998 to control the Mediterranean fruit fly, 123 people reported illness that was considered probably or possibly related to the spraying.
“Surveillance for Acute Pesticide-Related Illness During the Medfly Eradication Program Florida, 1998,” Journal of the American Medical Association Morbidity and Mortality Weekly Report, Vol. 282, No. 23 (December 15, 1999).http://jama.ama-assn.org/cgi/content/full/282/23/2204
Solutions
How to detect malathion
- There are over 250 products containing malathion on the market. Read labels to determine if the pesticide products and lice shampoos in your home are among them.
You can also find out if malathion is an ingredient in a pesticide product or lice shampoo on Pesticide Action Network Pesticides Database.
- If your district resorts to aerial or ground spraying near your home for mosquito or other pest control, contact your local health department to find out which chemicals are being used.
- Food: There is no way for parents to determine exactly how much malathion may be in their children’s food. You can get a rough idea of the fruits and vegetables that may contain malathion from:
The Environmental Working Group’s Report Card: Pesticides in Produce
Do You Know What You’re Eating? by Consumers Union
Consumers Union’s Update on Pesticides in Children’s Food
How to minimize exposure to malathion
- Avoid the use of pesticides whenever possible, especially near children. If you do have pesticides in your home, keep them tightly closed and out of the reach of children.
- Contact your local sanitation department or hazardous waste disposal program to find out how to dispose of pesticides properly.
- Earth 911 lists hazardous waste disposal sites by zip code.
- Prevent your home and lawn from becoming a breeding ground for mosquitoes. Unclog roof gutters, and remove all sources of standing water, such as old tires, bird baths, wading pools, and flowerpots.
See How To Keep Mosquitos From Biting for more tips on preventing and avoiding mosquito bites.
Alternatives
- Choose least-toxic pest control methods for your home garden, lawn and shrubs. Adopt Integrated Pest Management practices.
- If your area will be sprayed with malathion (or other chemicals), demand to be notified at least 24 hours in advance to keep children, pets and people with asthma or allergies inside. Close all windows and doors, and switch off air conditioning during spraying. Keep laundry or toys inside. Cover lawn furniture and swingsets, or rinse them afterwards.
- Buy certified organic foods, which are grown without synthetic pesticides, when you can. See 10 Fruits and Vegetables to Buy Organic.
Otherwise, wash fruits and vegetables well and peel them.
- The most effective means of treating lice is the removal of nits (egg sacks) by hand. There are anedoctal reports of success of food-grade oils used to smother lice and ease the removal of nits. Special lice combs also aid in lice and nit removal.
Avoid using lice shampoos containing pesticides, such as malathion, permethrin and lindane! Shampoos made with enzymes from natural vegetable extracts are a safe and effective alternative to toxic pesticides. The enzymes loosen the “glue” that holds nits in the hair so that they can be combed out.
For More information
Books, articles, factsheets and reports
Chemical Watch Factsheet: Malathion. Beyond Pesticides/National Coalition Against the Misuse of Pesticides.
http://www.beyondpesticides.org/main.html
Brenner, Loretta. “Malathion,” Journal of Pesticide Reform, Vol. 12, No. 4 (Winter 1992).
http://www.pesticide.org/malathion.pdf
Head Lice Information. Harvard School of Public Health, Updated August 9, 2000.
http://www.hsph.harvard.edu/headlice.html
Rumsey, Kay. "Dealing with Head Lice," Journal of Pesticide Reform, Vol. 18, No. 2 (Summer 1998).
http://www.pesticide.org/HeadliceUpdate.pdf
Olkowski, William, Sheila Daar, and Helga Olkowski. Common-Sense Pest Control: Least Toxic Solutions for Your Home, Garden, Pets, and Community. Newton, Conn,: Taunton Press, 1991.
OVERKILL: Why Pesticide Spraying for West Nile Virus May Cause More Harm Than Good.
Toxics Action Center and Maine Environmental Policy Institute, July 2001
http://www.meepi.org/wnv/mass.htm
Head-lice shampoos can be dangerous, Consumer Reports (September 2003).
http://www.consumerreports.org/main/detailv3.jsp?CONTENT%3C%3Ecnt_id=325835&FOLDER%3C%3Efolder_id=162687&bmUID=1061401446227
Other government agencies
National Pesticide Information Center
Oregon State University
333 Weniger Hall
Corvallis, OR 97331-6502
800-858-7378
http://npic.orst.edu/
U.S. Environmental Protection Agency
Office of Pesticide Programs
Ariel Rios Building
1200 Pennsylvania Ave. NW
Washington DC 20460
http://www.epa.gov/pesticides
Nonprofit organizations
Beyond Pesticides/National Coalition Against the Misuse of Pesticides (NCAMP)
701 E Street SE, Suite 200
Washington, DC 20003
202-543-5450
http://www.beyondpesticides.org/main.html
Northwest Coalition for Alternatives to Pesticides (NCAP)
P.O. Box 1393
Eugene, OR 97440
541-344-5044
http://www.pesticide.org
Pesticide Action Network North America (PANNA)
49 Powell Street, Suite 500
San Francisco, CA 94102
415-981-1771
http://www.panna.org
The National Pediculosis Association
P.O. Box 610189
Newton, MA 02461
781-449-NITS
http://www.headlice.org
Other websites
Pesticide Action Network Pesticide Database
http://www.pesticideinfo.org
Malathion Medical Research Index
http://www.chem-tox.com/malathion/research/index.htm
Pesticide Action Network Pesticide Advisor
http://www.panna.org/resources/advisor.dv.html
Other
The cancer-causing potential of malathion has been debated among U.S. EPA staff and other scientists. In EPA’s original February 2000 risk assessment of malathion, the agency classified malathion as a “likely human carcinogen.” This status was changed in April 2000, when EPA downgraded malathion to “suggestive evidence of carcinogenicity but not sufficient to assess human carcinogenic potential.” This lesser regulatory status results in fewer restrictions on the pesticide’s use.
Several dissenting EPA scientists and scientific advisors believe that the downgrade of this classification by EPA was in response to industry pressure. In order to achieve a lower status, it is alleged that test data was manipulated to reflect a lower incidence of cancer in animals exposed to malathion. The changed decision did not reflect any new data.
Letter from EPA Senior Toxicologist Dr. Brian Dementi Concerning Cancer and Non-Cancer Toxicology Issues. U.S. Environmental Protection Agency, November 8, 2000.
http://www.epa.gov/pesticides/op/malathion/dementi_1100.pdf
