Integrated assessment of toxic elements in PM10 during cold season in a coastal city of southern Peru

Abstract

This study evaluated concentrations of particulate matter with aerodynamic diameter ≤ 10 µm (PM10) and potentially toxic elements (PTEs) in three urban zones of Ilo, a coastal city in southern Peru, during the cold season (July–October 2022). The cold season is characterised by greater atmospheric stability and a lower mixing layer height, which favours pollutant accumulation and scenarios of higher potential exposure. Three contrasting zones were analysed: commercial (UCZ), industrial (UIZ), and peripheral (UPZ), through daily PM10 sampling and analysis of six PTEs (Al, As, Ba, Cu, Mn, and Zn). The UPZ recorded the highest mean PM10 concentration (23.8 ± 11.6 µg/m3), with 5% of daily records exceeding the World Health Organization (WHO) guideline of 45 µg/m3, and the highest concentrations of Cu and As, significantly higher than UIZ and UCZ (p < 0.001 and p = 0.015, respectively). The combined application of environmental indices classified UPZ as heavily contaminated by Cu and As, with extreme enrichment (enrichment factor, EF Cu = 2432; EF As = 2393) and considerable ecological risk (potential ecological risk, PER = 384). Back-trajectory analysis (HYSPLIT) revealed that the highest concentration episodes at UPZ coincided with air masses arriving from continental sectors at 1000 m altitude, including the direction of the local smelter. Health risk assessment identified significant non-carcinogenic risk exclusively at UPZ (hazard index, HI = 7.2), dominated by Cu (89%), while the incremental lifetime carcinogenic risk (ILCR) from As remained at acceptable levels. These findings are applicable to industrialised coastal cities with port, metallurgical, and urban activities in developing countries.