Environmental pesticide exposure in Honduras following hurricane Mitch

To investigate whether environmental contamination occurred in the wake of hurricane Mitch (30-31 October 1998), we conducted a population-based cross-sectional household survey in the barrio of Istoca, Department of Choluteca, Honduras. The goals were to evaluate chemical contamination of potable water and the extent of human exposure to chemicals as a result of extensive flooding.

The survey consisted of an environmental exposure assessment, which included assaying water and soil samples for contaminants, and taking blood and urine samples from 45 adolescents aged 15-18 years. We also made a subjective questionnaire assessment of 155 households.

There was significant contamination of the soil in Istoca, but no water contamination in the aftermath of hurricane Mitch. The soil levels of chlopyrifos and parathion were 30- and 1000-times higher, respectively, than the Environmental Data Quality Level. However, the most striking finding was the detection of elevated levels of chlorinated and organophosphate pesticides in adolescents. Toxicological analyses of serum specimens showed that 51% of the samples had elevated levels of 1,1-dichloro-2,2-bis-(p-chlorophenyl) ethylene (p,p-DDE) (range, 1.16-96.9 ng/ml) (US reference mean = 3.5 ng/ml) in adults). Dieldrin levels > 0.2 ng/ml were also present in 23% of the serum specimens (serum levels of this analyte in US adolescents are < 0.2 ng/ml). Of 43 urine samples analysed for organophosphate metabolites, 18.6% contained diethyl phosphate (DEP) at levels which were greater that the reference mean of 6.45 micrograms/g creatinine. We also detected elevated levels of p-nitrophenol (p-NP) and of 3,5,6-trichloro-2-pyridinol (3,5,6-TCPY) in 91% and 42% of the samples, respectively.

The elevated levels of chlorinated pesticides were surprising, since although these substances were banned in Honduras 15 years ago it appears that they are still being used in the country. Moreover, elevated levels of organophosphates were detected in the study adolescents even three weeks after the hurricane. Since these chemicals are usually cleared from the body quickly, our data suggest that the adolescents face an ongoing threat from pesticide exposure.