Lead and mercury levels in an environmentally exposed population in the Central Brazil.

The objective was to assess the level of exposure to lead and mercury in a population in the Pantanal region in Mato Grosso State, Brazil. Blood lead (PbB) (n = 119) and urinary mercury (HgU) (n = 109) in local residents were measured by atomic absorption spectrometry. Comparison of means and correlations between variables used analysis of variance (ANOVA) and linear regression, respectively, with 95% confidence intervals. Mean PbB was 2.82 +/- 1.53 mu g dL(-1). The comparison of PbB stratified by collection site (p <= 0.01), work activity (p <= 0.01), and consumption of locally produced cow's milk (p <= 0.05) showed statistically significant differences. There were also positive associations between PbB and collection site (p <= 0.01), participants' profession (p <= 0.05), local milk (p <= 0.01), and source of drinking water (p <= 0.01). Mean HgU was 1.41 +/- 0.98 mu g L-1. The levels only showed significant differences for participants' profession (p <= 0.01), and positive associations emerged between HgU and work activity (p <= 0.01) and body mass index (p <= 0.01). The samples showed low lead and mercury levels, similar to those found in other environmentally exposed populations. Despite these low concentrations, current knowledge on the toxicity of these metals shows that health effects can already be felt at levels that were previously considered safe, thus characterizing a health hazard.