Spatial heterogeneity of volatile organic compound pollution in a typical industrial park based on multi-point online monitoring: Pollution characteristics, health risks, and priority-controlled species

Emissions from industrial parks are crucial sources of ambient volatile organic compound (VOC) pollution, characterized by high concentrations, complex compositions, dispersed emission sources, and uneven spatial distribution. To better understand and address this issue, it is crucial to analyze the spatial differences in VOC pollution and associated health risks through multi-point monitoring. In this study, we established four online monitoring sites in a typical industrial park in Kaifeng, China. We monitored 115 VOC species and found significant differences in the concentration and chemical composition of total VOCs (TVOCs) among the four sites. Two sites were primarily composed of halohydrocarbons (49.80% and 41.21%), while the other two sites had a higher proportion of aromatics (54.78% and 39.03%). Acetaldehyde was the main contributor to ozone formation potential (OFP) at one site, while toluene was associated with the other three sites. The site with the highest VOC concentration and OFP also showed the highest secondary organic aerosol formation potential (SOAP). In terms of health risk assessment, acrolein posed a non-carcinogenic risk at all sites, but there were disparities in the carcinogenic risk among the four sites. 1,2-Dichloroethane at one site exceeded the definite risk limit, while 1,2-dibromoethane and chloroform were considered probable risk species at another site. Considering both the environmental impact and health risk, we used entropy-weighting to calculate a comprehensive control index (CCI). This index identified 1,2-dichloroethane as the Level Ⅰ controlled pollutant species at two sites, and toluene at the other two sites. This study highlights the spatial heterogeneity in VOC pollution and health risks within the industrial park, providing valuable insights for targeted pollution control strategies.