Human exposure monitoring pesticides

Table 6 Biomarkers Used in Biological Monitoring of Human Exposure to Some Groups of Pesticides...

The EPA has conducted four major studies of actual human exposure using monitors worn by random samples of people. The results are shocking. Smoking, clothes that had been dry cleaned and hung in closets, and heated water in showers and clothes washers (i.e., chloroform from chlorinated water) are major sources of human exposure to volatile organic compounds (VOCs), all of which exceeded outdoor exposure sources by two to five times at the median exposure level. The major sources of exposure to another VOC, p-dichlorobenzene, are toilet fresheners and mothballs. Pesticide exposure stems from two main sources (1) vapors emitted by soil into homes through basements and (2) soil tracked into buildings on shoes. Major stationary and mobile sources account for only 2 to 25 percent of personal exposure to the two dozen or so VOCs and pesticides that the EPA studied (Wallace 1993, 138 Ott and Roberts 1998). 

San RHC, Rosin MP, See RH, et al. 1989. Use of urine for monitoring human exposure to genotoxic agents. In Biological Monitoring for Pesticide Exposure Measurement, Estimation, and Risk Reduction. ACS Symposium Series 382, 98-116. 

INTRODUCTION 14 PESTICIDE CATEGORIES 15 PESTICIDE HANDLERS 15 Agricultural Pesticide Handlers 15 Tasks Performed by an Individual 16 Factors Affecting Exposure 16 Residential and Institutional Pesticide Handlers 18 Families of Pesticide Handlers 19 STUDY DESIGN CONSIDERATIONS 20 Worker Stratification 21 Routes of Exposure 21 Respiratory Exposure 21 Dermal Exposure 21 Sampling Strategy Selection 21 Statistical Analysis 22 PROTECTION OF HUMAN SUBJECTS 22 PESTICIDE EXPOSURE MONITORING METHODS 23 Passive Dosimetry 23... 

ICPS (1996). Biological Monitoring of Human Exposure to Pesticides, International Centre for Pesticide Safety, Milan, Italy (draft). 

Some examples of the use of LC-MS in the analysis of pesticides and metabolites in human urine for exposure monitoring are ... 

So, what remains is to assess human exposure to the pesticide. While I do not want to discuss exposure asessment extensively today - it is not our topic - I think a brief discussion would clarify how risk assessments based on toxicity data are used in completing a full hazard assessment. Exposure assessment is not a new art. It is, however, an area that requires a lot of work. Most often we do not have monitoring data to precisely describe human exposure, for example. Models are bing used to predict these exposure patterns but no standard process for making these predictions has yet been established. 

Through these studies we have acquired considerable data on human exposure as well as experience in designing and conducting research to monitor real-life exposure of pesticide applicators. Exposure is relevant to human health only in relation to the dose taken into the body, its toxicity, and the rate of excretion. In our studies we have monitored no group nor individual whose dose approaches a level which could affect human health. Our studies have shown that exposure and dose are influenced materially by human attire and habits, type and function of equipment, and safety precautions such as protective clothing or washing soon after exposure to a concentrate. 

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