Characterization and health impact assessment of hazardous air pollutants in residential areas near a large iron-steel industrial complex in Korea

Comprehensive air monitoring of hazardous air pollutants (HAPs) was conducted at four residential sites (three in the town and one in a suburb) in Pohang, where Korea's largest iron-steel industrial complex is located. The objectives of this study were to evaluate the occurrence and spatiotemporal distributions of HAPs and to identify important HAPs based on a health risk assessment. The 130 HAPs that were measured simultaneously included volatile organic compounds (VOCs), carbonyls, polycyclic aromatic hydrocarbons (PAHs), phthalates, and heavy metals (HMs). The impact of industrial emissions on the ambient levels of HAPs in Pohang appeared to be significant, because the concentrations of multiple HAPs at residential sites near the industrial complex were considerably higher than those at the suburban site. The concentrations of VOCs (except formaldehyde) and HMs did not exhibit a specific seasonal pattern, but PAH levels were generally 4-5 times higher in winter than in summer. The cumulative cancer risks posed by 28 HAPs averaged over the three residential sites and the suburban site were 2.3 x 10(-4) and 1.6 x 10(-4), respectively, both of which exceeded the tolerable risk criterion of 1 x 10(-4). Benzo[a]pyrene posed the highest risk, followed by As, formaldehyde, benzene, and dibenz[a,h] pyrene. However, no single HAP exceeded the non-cancer risk criterion of 1. These results support the need for stricter controls on emissions of PAHs, VOCs, and HMs in Pohang, particularly for sources in the iron-steel industrial complex.