Characteristics and health risk assessment of polycyclic aromatic hydrocarbons associated with dust in household evaporative coolers

Abstract

This study reports a characterization of indoor polycyclic aromatic hydrocarbons (PAHs) associated with dust (dust-PAHs) in household evaporative coolers and their associated health effects. Extensive analysis showed that the indoor dust-PAHs stemmed mostly from pyrogenic sources (vehicular emissions) with mean total concentrations limited between 131 and 429ngg(-1). The distribution pattern of PAHs based on number of rings exhibited the following order of decreasing relative abundance: 4>3 > 5>6 > 2 rings. Results indicate that the mutagenicity of dust-PAHs exceeded their carcinogenicity, but that the potential carcinogenic effects are still significant. The mean lifetime cancer risk for different age groups for three pathways based on Model 2 (dermal (1.39x10(-1) to 1.91x10(-2)), ingestion (2.13x10(-3) to 8.08x10(-3)) and inhalation (1.62x10(-7) to 4.06x10(-7))) was 7.4-146 times higher than values predicted by Model 1 (dermal (5.13x10(-5) to 3.03x10(-3)), ingestion (9.34x10(-5) to 1.31x10(-3)) and inhalation (7.13x10(-20) to 1.68x10(-20))). Hence, exposure to dust-PAHs in household evaporative coolers lead to high risk, especially for children (less than 11 years) (HQ=2.71x10(-20) to 54.8 and LTCRs=7.13x10(-20) to 1.39x10(-1)). Strategies should be considered to eliminate such pollutants to protect people, especially children, from the non-carcinogenic and carcinogenic effects by changing household evaporative coolers with other cooling systems.