Lead exposure from conventional and cottage lead smelting in Jamaica

A survey was conducted to determine the distribution and determinants of environmental and blood lead levels near a conventional and several cottage lead smelters and to assess the relationship between environmental and blood lead levels in a tropical developing-country setting. Fifty-eight households were studied in the Red Pond community, the site of the established smelter and several backyard smelters, and 21 households were studied in the adjacent, upwind Ebony Vale community in Saint Catherine Parish, Jamaica. Households were investigated, using questionnaires, soil and housedust lead measurements, and blood lead (PbB) measurements from 372 residents. Soil lead levels in Red Pond exceeded 500 parts per million (ppm) at 24 percent of household (maximum--18,600 ppm), compared to 0 percent in Ebony Vale (maximum 150 ppm). Geometric mean PbB levels >25 micrograms per deciliter (ug/dL), was more than twice that Ebony Vale in all age groups (p<0.0005). Within Red Pond, proximity to backyard smelters and to the conventional smelter were independent predictors of soil lead (p<0.05). Soil lead was the strongest predictors of PbB among Red Pond subjects under 12 years of age. The blood lead--Soil lead relationship in children differed from that reported in developed countries; blood lead levels were higher than expected for the household-specific soil lead levels that were observed. These data indicate that cottage lead smelters, like conventional ones, are a hazard for nearby residents and that children exposed to lead contamination in tropical, developing countries may be at higher risk for developing elevated blood levels than similarly-exposed children in developed countries (AU)

Blood lead and zinc protoporphyrin levels in donkeys and mules near a secondary lead smelter in Jamaica

During the course of an investigation into community lead poisoning near a secondary lead smelter in Jamaica, blood lead and zinc protoporphyrin levels were measured in 8 exposed and 6 (3 Jamaican, 3 US) unexposed donkeys and mules. The blood lead levels of 6 animals in the contaminated area ranged from 7.5 to 33 ug/d1 (mean=17.6 ug/d1), compared to 1.8 and 2.4 in unexposed Jamaican animals. More striking was the difference in zinc protoporphyrin levels; all 8 exposed donkeys and mules had values between 900 and 1890 ug/d1, compared with a range of 34-46 ug/d1 for 3 Jamaican control donkeys. These findings suggest that zinc protoporphyrin may be a useful method of screening for subclinical lead toxicity in equines (AU)