Bioavailability of lead-contaminated soils in a tropical environment: Jamaica

Abstract

The impact of soil lead bioavailability on exposure assessments is well documented in developed countries. However, in tropical developing countries such as Jamaica, few studies address its importance. An assessment of lead bioavailability in Jamaican soils is necessary as, over the past 40 years, cases of lead poisoning have consistently occurred. Exposure studies have indicated that the main pathway to human uptake is soil ingestion, and hence, a determination of lead bioavailability in Jamaican soils can significantly improve community health risk assessments. Given this need, this study seeks to assess the lead bioavailability in soils from sites previously found to have high lead contamination. These sites are: Mona Commons and Kintyre, both in the Parish of St Andrew, and Fraser’s Content in Parish St Catherine. The chosen sites have different soil characteristics, are now densely populated and have a history of childhood lead poisoning. Investigations were conducted using the Relative Bioavailability Leaching Procedure, which is an in vitro technique assessed and approved by the United States Environmental Protection Agency for specific site assessments of lead contamination. Three runs were conducted using representative samples of particle size less than 250 µm from each site. The results indicated relative bioavailability of Fraser’s Content, Mona Commons and Kintyre of 60%, 58% and 45%, respectively. These results are within the range reported in other countries (USA, Australia) with similar sources of contamination. It was concluded that the methodology may be used to assess lead bioavailability in Jamaican soils.