No Spray News, March 11, 2002, Page 2

Malathion, the insecticide used here for mosquito spraying, has a low acute toxicity. (It would take about a shot glass of it to kill you outright.) But there are other health effects to consider:

Agreed: It's a Mutagen, and affects the Immune System.
USDA Pesticide Information Profile says so.

Mutagenic effects: Malathion produced detectable mutations in three different types of cultured human cells, including white blood cells and lymph cells [2,8]. It is not clear what the implications of these results are for humans.

Organ toxicity: The pesticide has been shown in animal testing and from use experience to affect the central nervous system, immune system, adrenal glands, liver, and blood. It has been reported that single doses of malathion may affect immune system response [2].

Journal of
Pesticide Reform
Concurs --

Mutagenicity

Malathion is mutagenic (causing genetic damage) in human, animal and bacteria cells.

Frequencies of chromosomal aberrations were significantly higher in cotton field workers exposed to mala- thion and other pesticides. 38,39 (The design of the study did not permit conclusions about a specific chemical.) Increased chromosome breaks and aberrations occurred following acute malathion human poisonings 40 and in human blood cells exposed to malathion. 41,42 Malathion caused sister- chromatid exchanges (exchanges of genetic material within a pair of chromosomes) in human blood cells 41-44 and fetal cells. 45

Malathion has, also caused mutations in laboratory animals, including rnice and hamsters, 46-49 and induced DNA breakage in the bacteria Escherichia coli. 50

In some cases malathion induced genetic damage at doses far below acutely toxic levels 45,51 and effects can be cumulative.45

Immune System Effects

Eradication programs for pests such as mosquitoes and fruit flies expose thousands of people to malathion applied in aerial applications. These type of pesticide applications often provoke complaints of allergic reactions and flu-lke symptoms. 8,25,74 In laboratory animals, oral doses of purified malathion disrupted immune system function In rnice at levels far below the dose required to cause cholinesterase inhbition. 75 This work suggests that malathion can cause sensitization and allergic reactions in humans and anirnals. Impurities present in technical malathion can further disrupt immune system function. 76-78

These immune system effects may have serious human health implications. Stimulation of immune responses may increase allergic reac- tions and also cause tissue damage. 77-78

Immunosuppression may enhance susceptibility of mammalian system to bacterial viral or parasitic infection or possible increased tumor formation. 77 Changes in immune system functions in anirnals exposed to impurities in malathion may also trigger lung damage. 79 Both malathion and the impurities in malathion can directly affect one immune system function that creates risks for individuals with liver damage. 80