Exposure assessment of chlorinated pesticides in the environment

A preliminary study was conducted to characterize the temporal trends of chlorinated pesticides in the environment from measured concentrations of residues in human adipose tissue. Samples obtained from autopsy patients in the North Texas area were analyzed for the presence of selected chlorinated pesticides by using electron-capture gas chromatography. The results indicate a greater than 97% occurrence for each compound with the exception of 1,1-dichloro-2-(o-chlorophenyl)-2-(p^'-chlorophenyl)ethane(o,p'-DDE) and 1,1,1-trichloro-2-(o-chlorophenyl)-2-(p'-chlorophenyl)ethane(o,p’-DDT), each of which occurred in only 54% of the sampled population. Statistical analyses of the data showed positive correlations between concentrations of pesticides and age for some of the compounds (p < 0.05). However, there was no statistically significant difference between the concentrations of pesticides in males and females. The geometric means of pesticides concentrations were compared with those reported in previous surveys of the general population conducted by the U.S. Environmental Protection Agency (U.S. EPA). The results of this study indicate a declining temporal trend in the environment for proscribed compounds such as DDT, while pesticides whose uses are currently restricted do not indicate any decrease in the environment.