Distribution, Fate, Inhalation Exposure and Lung Cancer Risk of Atmospheric Polycyclic Aromatic Hydrocarbons in Some Asian Countries

Abstract

A large-scale monitoring program, the Asia Soil and Air Monitoring Program (Asia-SAMP), was conducted in five Asian countries, including China, Japan, South Korea, Vietnam, and India. Air samples were collected using passive air samplers with polyurethane foam disks over four consecutive 3-month periods from September 2012 to August 2013 to measure the seasonal concentrations of 47 polycyclic aromatic hydrocarbons (PAHs), including 21 parent and 26 alkylated PAHs, at 176 sites (11 background, 83 rural, and 82 urban). The annual concentrations of total 47 PAHs (∑47PAHs) at all sites ranged from 6.29 to 688 ng/m(3) with median of 82.2 ng/m(3). Air concentrations of PAHs in China, Vietnam, and India were greater than those in Japan and South Korea. As expected, the air concentrations (ng/m(3)) were highest at urban sites (143 ± 117) followed by rural (126 ± 147) and background sites (22.4 ± 11.4). Significant positive correlations were found between PAH concentrations and atmosphere aerosol optical depth. The average benzo(a)pyrene equivalent concentration (BaPeq) was 5.61 ng/m(3). It was estimated that the annual BaPeq concentrations at 78.8% of the sampling sites exceeded the WHO guideline level. The mean population attributable fraction (PAF) for lung cancer due to inhalation exposure to outdoor PAHs was on the order 8.8‰ (0.056-52‰) for China, 0.38‰ (0.007-3.2‰) for Japan, 0.85‰ (0.042-4.5‰) for South Korea, 7.5‰ (0.26-27‰) for Vietnam, and 3.2‰ (0.047-20‰) for India. We estimated a number of lifetime excess lung cancer cases caused by exposure to PAHs, which the concentrations ranging from 27.8 to 2200, 1.36 to 108, 2.45 to 194, 21.8 to 1730, and 9.10 to 720 per million people for China, Japan, South Korea, Vietnam, and India, respectively. Overall, the lung cancer risk in China and Vietnam were higher than that in Japan, South Korea, and India.

Environmentally prevalent polycyclic aromatic hydrocarbons can elicit co-carcinogenic properties in an in vitro murine lung epithelial cell model

“…PAHs are formed from the incomplete combustion of organic material containing two or more fused benzene rings (ATSDR 2005 ) and are found in high amounts in firsthand, secondhand, and thirdhand smoke from cigarettes, at hazardous waste sites, oil production sites, and are components of diesel exhaust (ATSDR 2005 ; Lee et al 2010 ). PAHs also attach to particulate matter (PM), both PM 2.5 and PM 10 , and elevated PAH concentrations have been observed in mega-cities compared to rural and undeveloped natural environments (Hong et al 2016 ; Zhang et al 2016 ). Thus, based on the numerous potential exposures, PAHs are an international public health concern.…”

Recent analytical methods for atmospheric polycyclic aromatic hydrocarbons and their derivatives

“…For the analysis of PAHs in airborne particulates, GC-MS using electron ionization (70 eV) mode and HPLC-fluorescence detection (HPLC-FL) are the most common methods (Araki et al, 2009;Chen et al, 2011;Liu et al, 2007;Zhang et al, 2010). Applications of these methods to all or some subset of the US Environmental Protection Agency (US-EPA) 16 priority PAHs (Ma et al, 2013;Tang et al, 2015;Xu, Lv, Cheng, & Li, 2015;Zhang et al, 2016) and World Health Organization (WHO) 17 PAHs (Feng et al, 2012;Hong et al, 2016;Omar et al, 2002) were determined because of their carcinogenicity and/or mutagenicity. Recently, GC-MS and HPLC-FL methods were reported for determining benzo[c]fluorene, whose relative potency factor with respect to the mutagenicity of benzo [a]pyrene are about 20, as reported by US-EPA (Morisaki et al, 2016;Yagishita et al, 2015).…”

Substantial reductions in ambient PAHs pollution and lives saved as a co-benefit of effective long-term PM2.5 pollution controls

“…Reduced cancer risks were also found for the periods with mega-events, such as the APEC meeting (Xie et al, 2017). It should be noted that uncertainties are inherent in cancer risk assessment, as a lack of knowledge about the factors affecting exposure or toxicity assessment (Hong et al, 2016).…”