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 429 ng g−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 (1.39 × 10−1 to 1.91 × 10−2), ingestion (2.13 × 10−3 to 8.08 × 10−3) and inhalation (1.62 × 10−7 to 4.06 × 10−7)) was 7.4–146 times higher than values predicted by Model 1 (dermal (5.13 × 10−5 to 3.03 × 10−3), ingestion (9.34 × 10−5 to 1.31 × 10−3) and inhalation (7.13 × 10−20 to 1.68 × 10−20)). Hence, exposure to dust-PAHs in household evaporative coolers lead to high risk, especially for children (less than 11 years) (HQ = 2.71 × 10−20 to 54.8 and LTCRs = 7.13 × 10−20 to 1.39 × 10−1). 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. This work is novel in that there are no reports to our knowledge of the nature and impacts of dust-PAHs for indoor environments associated with evaporative coolers as a transportation conduit between ambient air and living spaces. The results of this work have broad implications for other regions owing to the pervasiveness of evaporative coolers and dust.
- Carcinogenic and non-carcinogenic
- Evaporative cooler
ASJC Scopus subject areas
- Health, Toxicology and Mutagenesis