Biological monitoring of workers at a recently opened hazardous waste disposal site.

A health assessment was performed in a recently opened landfill for toxic waste. The site has received 14,000 tons of hazardous waste, confined in drums or deposited as bulk material, which were left outdoors for seven months. The analysis in some samples showed that the waste is rich in heavy metals, however we did not find high levels of contaminates in air or surface soil in different areas on-site. When compared to a control group, high-risk workers show higher levels of arsenic in urine and hair, and non-specific symptoms (irritability and insomnia). But among groups, we did not find statistical differences in urinary mercury, blood lead, phenol in urine, cadmium in hair or blood, sister chromatid exchange values, lymphocytes proliferation kinetics, liver function tests, and other non-specific symptoms. We considered this project as a background study for human exposure to hazardous waste, providing useful results for the future evaluation of chronic effects in the same population.