Pesticides pulmonary effects

Kay, K. (1970) Pesticides and associated health factors in agricultural environments effects on mixed-function oxiding enzyme metabolism, pulmonary surfactant and immunological reactions, in Pesticides Symposia, R. Dichmann (Ed.), Halos Co., Miami, FL. 

These pesticides inhibit acetylcholine esterase and produce effects similar to, but much milder and more transient than, nerve agents. In some cases, inhalation exposure may also lead to pulmonary edema. 

Toxicities for these compounds vary over a wide range. Mercury based pesticides may produce eye and/or skin irritation. Some mercury compounds are readily absorbed across the skin and can produce systemic effects. Inhalation of some mercury based pesticides can cause damage to the respiratory system leading to pulmonary edema. Some can cause nausea and/or vomiting. Many impact the nervous system. 

The world s worst industrial disaster occurred in Bhopal, India, in 1984 in which nearly 40 metric tons of methyl isocyanate was released from a pesticide plant killing over 3000 people. Most deaths resulted from pulmonary edema within 3 days of accident. Many follow-up studies indicated pulmonary, ophthalmic, neurological, reproductive, immunologic and hematologic toxic effects among the survivors. 

PU are compounds formed by reacting the polyol component with an isocyanate compound, typically toluene diisocyanate (TDI) methylene diisocyanate (MDI) or hexamethylene diisocyanate. Polyols are relatively non-toxic (i.e., polyether type polyols are found to be safe, because they are low in oral toxicity with almost no irritation effect to the eyes and skin), however, isocyanates are highly toxic and the product can have a significant toxicity if remnants of isocyanate are in it, which manifests itself mainly as a respiratory (as well as a dermal) hazard. Exposure to the vapour of isocyanates directly may cause irritation for the eyes, respiratory tract and skin. Such an irritation may be too severe to produce bronchitis and pulmonary oedema. As health hazards of isocyanates are considered, one immediately remembers one of the worst industrial disasters of the 20th century, that occurred in Bhopal, India, because of the toxic cloud of methyl isocyanate was released accidentally from the Union Carbide pesticide factory in December 1984. An estimated 3,000 people died immediately with a final of some 20,000, most suffocating from the cloud s toxic chemicals, and some 50,000 were injured, most were residents living near the plant. 

All organophosphates recommended as pesticides are subjected to screening for delayed neurotoxicity through research into their influence on neurotoxic esterase, as well as in direct experiments on hens. Enough data have been collected to show pesticides as potential producers of various delayed adverse effects, which may be irreversible or somewhat reversible (atherosclerosis, hepatocirrhosis, pulmonary fibrosis, demyelinization of nerve trunks). These effects should be projected and considered in human health assessments of pesticides. 

Important Point Methyl isocyanate is an organic chemical that is used in the production of pesticides. Methyl isocyanate, commonly referred to as MIC, is extremely toxic to humans. Short-term exposure may cause death or adverse health effects, including pulmonary edema (respiratory inflammation), bronchitis, bronchial pneumonia, and reproductive effects. 

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