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Malathion's Real Name is
Dimethoxy Phosphino Thioyl Thio Butanedioic Acid Diethyl Ester
Malathion Molecule
10 H19 O6 P S2

by Dr. Wayne Sinclair, M.D.
Allergy, Asthma & Immunology (Immunology Board Certified), Vero Beach, Florida
Richard W. Pressinger, M.Ed., Tampa, Florida

The Medical Research below was located from the University of Florida
and University of South Florida Medical Libraries.

Considerable information has been promoted by the agricultural interests regarding the safety of malathion. There is, however, another disturbing side to this chemical. Whereas, the original safety of malathion was based solely on its ability not to cause immediate death in lab animals, scientists now realize there are many other ways malathion can harm health, many of which can be quite subtle and not detected immediately.. Malathion effects can include weakening of the immune system, neurological damage, reproductive disorders, harm to the unborn child during pregnancy, harm to second generation offspring and mutations/genetic damage to DNA.  In essence, the chemical is causing accelerated aging to various biological systems within the individual.  Harm to many aspects of wildlife is also extensive from malathion. Documentation to all of these effects can be viewed in the research articles below. .

Malathion Index
Health Effects Research Summaries Included in this Report
click topic below for more information or scroll through the web site

Human Deaths from Malathion - 5 die and 2,800 poisoned after malathion spraying in Pakistan
Intestinal Disorders - found higher in children born after California aerial malathion spraying
Intestinal Disorders in Test Animals - more evidence supporting intestinal defects in children
Leukemia -
Child leukemias develop after homes sprayed with malathion and other pesticides
Kidney Damage -
physician finds kidney damage after patient sprays malathion in home
Human Birth Defect - suspected from exposure to malathion lice shampoo
Brain Damage - for unknown reasons malathion causes far more damage in older brains
Chromosome Defects - found in human blood cells exposed to malathion
Gene Loss - malathion is able to literally "knock-off" genes from our DNA molecule
Review of Malathion Genetic Studies - technically oriented - recommended for health professionals
Health Disorders found in Second Generation Offspring
- evidence for long term effects
Lung Damage - unusual effect from malathion ingredient - not found in other pesticides
Birth Defects - occurs in hens after malathion feeding
Impurities in Malathion - highly toxic compounds increase during storage due to time and heat
Immune System Weakening - thereby increasing risk of bacteria or viral infections (2 studies)
Sunlight Makes Toxic - malathion reacts with ultraviolet light to become more toxic
Impurities Weaken Detoxification - impurities found to weaken ability of liver to detoxify
Breakdown of Malathion - time periods for malathion breakdown in soil - forming of malaoxon
Fish Heart Defects - heart defects appear in fish exposed to malathion
Fish Gill Damage - low levels of malathion cause deterioration of Blue Fish gills
Frog/Tadpole Mutations - effects of malathion on causing mutations in frogs
Shrimp Effects - malathion at low levels affects a shrimp's ability to locate food
Lizard Organ Damage - small lizards suffer internal organ damage from very low level malathion
Unknown Risks of Malathion - Surprising information about what we do not know

and Bob Crawford says there is no evidence of harmful effects of malathion.........

Health Effects Research Summaries

Malathion Not as Safe as Believed - 5 Die - 2,800 Poisoned 
SOURCE: Archives in Toxicology, 42:95-106, 1979

The following information is from the report from the Bureau of Tropical Diseases, Center for Disease Control, Atlanta, Georgia entitled "The Toxicological Properties of Impurities in Malathion." Below is a direct quote from the introductory abstract to the article:

"During a malaria eradication program in Pakistan in 1976, out of 7,500 spray men, 2,800 became poisoned and 5 died. The major determinant of the poisoning has been identified as isomalathion present as an impurity in the malathion. It seems almost certain that the isomalathion was produced during storage of the formulated malathion.

The quantitative correlation found between isomalathion content and toxicity of many field samples of malathion has been confirmed by an examination of mixtures of pure compounds. Addition of known amounts of isomalathion to technical malathion indicates that other active substances are present. These impurities have been identified (trimethyl phosphorothioates) and have been shown to behave like isomalathion in potentiating the toxicity of malathion. Some preliminary work on their toxicological properties is reported."
Drs. W.N. Aldridge, J.W. Miles, D.L. Mount and R.D. Verschoyle
Toxicology Unit, Medical Research Council Laboratories
Pesticides Branch, Vector Biology and Control Division
Center for Disease Control, Atlanta GA