Human bio-monitoring study around a plant that recycles and refines precious metals in Central Italy.

In an area characterized by the presence of a plant that recycles and refines precious metals the study aims to evaluate the exposure to the plant emissions of the residents in the neighbourhood using human urinary biomarkers, in comparison with those obtained in a reference and in an urban area and with the data concerning dispersions of plant emissions obtained through a specific diffusional model. 153 subjects in the study area, 95 in the urban area and 55 in the reference area, aged 18-60years, answered to a self-administered questionnaire and collected their 24-h urine. Urinary concentrations of antimony, silver, cadmium, cobalt, chromium, mercury, nickel, platinum, creatinine, and the porphyrin patterns were detected. The results for the 3 areas were compared using parametric and non-parametric tests. Significant higher concentrations of mercury, cadmium, silver and nickel are observed in the study area in comparison with the reference area, but no differential distribution was observed by different levels of environmental pollution defined by the study's diffusion model, and no correlation was found between the concentrations of altered urinary porphyrin and metals. Life styles being equal, residents in the study area as well as residents in the urban area have high urinary levels of mercury, silver and nickel in comparison with the reference area, suggesting common environmental pressures probably related to diffuse gold processing activities, suggesting common environmental pressures. The excess of cadmium only in the study area suggests a role played by exposure to plant emissions, even if a differential distribution was not observed by different levels of environmental pollution.