Pesticide exposure fumigants

Production, Import/Export, Use, Release, and Disposal. Hexachlorobutadiene is not produced for commercial purposes in the United States, however small amounts are imported from Germany. Hexachlorobutadiene is mainly produced as a by-product of chlorinated hydrocarbon synthesis and is a primary component of "hex-wastes" (EPA 1982b). Its uses as a pesticide and fumigant have been discontinued. Hexachlorobutadiene is disposed chiefly by incineration, and to a lesser extent by deep well injection and landfill operations (EPA 1982b). More recent production and release data would be helpful in estimating human exposure to hexachlorobutadiene. 

Common operations in which exposure to DBCP is likely to occur are during its production and during its formulation into pesticides and fumigants. 

Pesticides are used to kill household insets, rats, cockroaches, and other pests. Pesticides can be classified based on their chemical nature or use as organophosphates, carbonates, chlorinated hydrocarbons, bipyridyls, coumarins and indandiones, rodenticides, fungicides, herbicides, fumigants, and miscellaneous insecticides. The common adverse effects are irritation of the skin, eyes, and upper respiratory tract. Prolonged exposure to some chemicals may cause damage to the central nervous system and kidneys [32,33]. 

Exposure to l,2-dibromo-3-chloropropane has occurred during its production and use as a pesticide, nematocide and soil fumigant however, production is believed to have ceased. It has been detected at low- levels in ambient air, water and soil. 

In the case of pesticides which are not ChE inhibitors, exposure is measured by the analysis of blood and/or urine for the active ingredient or its metabolites. Baseline levels of pesticides and/or metabolites are not usually determined, with the exception of methyl bromide. In this case, a blood sample is taken to check for bromide ion before fumigators use the pesticide. Blood and urine tests are run only in the case of spills or other accidents to assist in identifying the cause of poisoning or to monitor workers in a workplace. Paraquat, chlorinated hydrocarbons, mercury, p-nitrophenol, and dinitrophenol are examples of pesticides or metabolites of pesticides that have been found in the urine of exposed workers. 

Expensive biological measures, including blood and adipose levels of TCDD, do not correlate with clinical symptoms (Demers and Perrin 1995). Elevated liver function tests in the presence of chloracne indicate exposure. Dioxin has no antidote, and most symptoms require supportive management. No specific literature addresses psychiatric treatment issues of dioxin poisoning. In most exposures to an unknown herbicide, fumigant, or pesticide, the clinical evaluation should proceed as described in Chapter 4. 

In this bioassay, activity due to contact cannot be distinguished from activity through fumigant action because the containers were sealed. There are two ways to address this problem. The first is to ventilate the chamber to draw off all vapors as is done with a number of pesticide bioassays (e.g., Morse et al. 1986), thus restricting exposure to direct contact. The second simply is to isolate the test semiochemical from physical contact the subjects to that the only means of exposure is by fumigant action. This is illustrated by bioassays of chromenes and benzofurans from Encelia spp. developed by Isman and Proksch (1985) as follows. 

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