Characteristics and health risk-oriented source of VOCs contamination in a typical non-ferrous metal smelting plant and its surrounding area for prioritizing the VOCs control strategies

Non-ferrous metal smelting plant (NMSP) discharges quantities of volatile organic compounds (VOCs) into the surrounding residential areas (RA). A total of 92 VOC species were identified. VOC concentrations in NMSP ranged from 88.1 to 154.4 μg/m³ , with aromatic hydrocarbons (AHs) and aliphatic hydrocarbons (AIHs) accounting for more than 75.0 % of TVOCs. Spatial distribution revealed a significant negative correlation between VOCs concentration and distance from NMSP (p < 0.01), and contaminants predominantly transported southward over short and medium distances. Health risk assessment revealed that the inhalation carcinogenic risks in NMSP and RA were 3.0 × 10^-5 and 1.2 × 10^-5, exceeding the acceptable risk level (1.0 ×10^-6). Benzene (AHs), 1,2-dichloroethane (halogenated hydrocarbons; HHs), and 1,2-dichloropropane (HHs) were the primary contributors. Health risk-oriented source apportionment further showed that NMSP emissions contributed 50.54 % of the carcinogenic risk and 49.84 % of the non-carcinogenic risk in RA. Further prioritizing the control efficiency of AHs and HHs emissions from NMSP to over 96.1 % and 97.1 % would reduce the carcinogenic risk level by one risk category and eliminate non-carcinogenic concerns in RA. Greater emphasis should be placed on high-risk compounds, rather than solely on high-concentration compounds. This study provides critical insight for prioritizing VOC control strategies to maximize environmental and health co-benefits.