Assessment of Human Exposure to Airborne Trace Metals in a Residential Area Near an Industrial Waste Pile in Southeastern Brazil

Resumo

Introduction: Chronic exposure to Pb, Mn, Cd, Cr, and Ni may result in severe health outcomes such as carcinogenicity, neurotoxicity, and respiratory disorders. In this study, the concentrations of these toxic metals were assessed in a residential complex located near the waste disposal area of the Companhia Siderúrgica Nacional (CSN), in Volta Redonda-RJ, Brazil. Objective: To determine the concentrations of these metals in ambient air and to evaluate the potential impact on the exposed population by analyzing biomarkers of internal exposure. Material and Methods: Air sampling was conducted at four fixed monitoring sites over a period of four years, targeting stationary emission sources. The concentrations of metals in air and biological samples were determined using ICP-MS and GFAAS, respectively. To ensure analytical quality, certified reference materials were used: EP-H3 Drinking Water (EnviroMAT), Lyphochek Whole Blood Metals Control, and Lyphochek Urine Metals Control (BIORAD).
Results and Conclusion: The study included five air monitoring campaigns with the participation of 211 residents. In all air samples, Cr levels exceeded the 0.1 ng.m-3 limit set by IRIS-USEPA, and 40.5% of samples surpassed the 3.0 ng.m-3 Ni threshold from NYSDEC, among the most stringent standards worldwide. Pb, Cd, and Mn concentrations were below regulatory air quality limits. Biological samples revealed (in µg.L-1 unless noted): Cd-U: 0.53 (0.20–3.70), Cd-B: 0.70 (0.28–1.62), Cr-U: 0.35 (0.22–2.98), Ni-U: 3.76 (1.40–39.75), Mn-B: 7.69 (2.69–20.54), Mn-U: 0.94 (0.39–20.44), and Pb-B: 1.76 µg/dL (0.39–8.32). Although some metals did not exceed air quality standards, internal exposures were significant. 34% of participants presented blood lead levels above the national biological reference value (95% Confidence Interval: 1.89–2.04 µg.L-1).50% had urinary chromium levels exceeding reference limits (95% CI: 0.033–0.043 µg/g creatinine).68% exhibited elevated urinary nickel levels (95% CI: 1.294–1.793 µg.L-1), with a mean of 3.61 µg.L-1, which surpasses levels typically observed in occupationally exposed cohorts. These findings underscore a significant environmental exposure scenario, with potential implications for neurobehavioral, genotoxic, and endocrine-disrupting effects. The strong correlation between ambient metal concentrations and internal biomarkers reinforces the need for continuous environmental health surveillance and public health intervention strategies.