Baseline concentrations, source apportionment, and probabilistic risk assessment of heavy metals in urban street dust in Northeast Brazil

• Published in: The Science of the total environment 2023-02, Vol.858, p.159750, Article 159750
• Main Authors: Lima, Luiz Henrique Vieira, do Nascimento, Clístenes Williams Araújo, da Silva, Fernando Bruno Vieira, Araújo, Paula Renata Muniz
• Format: Article
• Language: English
• Subjects: Anthropogenic sources; Human health; Pollution; Potentially toxic elements; Vehicle emission
• ISSN: 0048-9697
• DOI: 10.1016/j.scitotenv.2022.159750

Heavy metal pollution by accelerating urbanization is an emerging socio-environmental issue that poses a potential risk to human health and the environment. In this scenario, street dust is a primary source of contaminants. Here, the metal concentrations in street dust of one of the biggest Brazilian cities were assessed aiming to identify and quantify the sources of contamination. The metal bioaccessibility and estimated probabilistic (non)–carcinogenic risks to humans were also evaluated. Thirty-six dust samples were collected in the metropolitan region of Recife. Results showed that the traffic governed the distribution and accumulation of metals in street dust. Emissions from vehicles were the primary source (> 70 %) of heavy metals, except for Cd, which had a mixed origin (natural, traffic, and industrial). Moderate to heavy dust contamination by Ba, Cu, Mn, Pb, and Zn were found, with a very high potential ecological risk. The main exposure route depended on the metal. Barium, Cu, and Pb had ingestion rather than dermal contact as the main route of exposure, while inhalation and dermal contact posed the main risks to Mn and Cr, respectively. The risk for children was higher than for adults. The probabilities of unacceptable carcinogenic risk scenarios (TCRI >10–6) for children and adults were 27 and 4 %, respectively, with Cr being the most concerning metal for the health of the urban population. [Display omitted] •Traffic emissions were the primary source of contamination in the city.•Risk assessment for heavy metals with bioaccessibility were combined.•There is a high probability of cancer in children exposed to street dust.•Chromium poses the highest risk to the health of the urban population.