Assessment of pesticides in soil from obsolete pesticides stores: a Caribbean case study

The fate of highly hazardous or persistent pesticides in soils and their potential for environmental and health risks depends on the physical and chemical properties of the pesticide, soil properties including biological health and climatic conditions. Assessing the fate and impact of pesticides in soil is complicated in the Caribbean due to the high diversity of soils and duality of climate. The FAO supported national competent authorities from 11 countries in the Caribbean in the assessment of obsolete stocks and potentially contaminated soil. The Environmental Management Tool Kit (EMKT) prioritised Fond Cole and Camden Base as the only critical sites. Preliminary site investigations that utilised the rapid environmental assessment (REA) methodology identified that contamination was restricted to an impervious layer at the Camden site. Pesticide properties varied across groups, with the organochlorides exhibiting greater sorptive capacity and lower leaching potential relative to the organophosphates. All tested soils were non-saline with alkaline pH and notably sandy in texture with low adsorptive capacity. Analysis of pesticide levels revealed low to undetected quantities across contaminated sites. Traces of Endrin and Dieldrin were found in Marienburg, Suriname. Overall, assessment of soil contamination from stored obsolete pesticides revealed minimal contamination, however, detailed assessment considering contamination gradients should be performed where pesticides were identified.