Sources and potential health risk of gas phase PAHs in Hexi Corridor, Northwest China

Abstract

Gas phase polycyclic aromatic hydrocarbons (PAHs) in Hexi Corridor, Northwest China were determined during heating and non-heating seasons, respectively, using passive air samplers. Polyurethane foam (PUF) disks were chosen as the sampling medium. Fifteen PAHs out of the 16 PAHs classified by the United States Environmental Protection Agency (U.S. EPA) were detected in this field sampling investigation. The atmospheric levels of sampled PAHs were higher at urban sites than that at rural sites among 14 sampling sites and increased during heating season. The highest concentration (11.34 ng m(-3)) was observed in Lanzhou during the heating season, the capital and largest industrial city of Gansu Province. PAH contamination in air was dominated by three aromatic ring congeners. Possible sources of PAHs were apportioned using PAH species ratios and the principle component analysis (PCA) combined with a multiple linear regression (MLR) method. Fossil fuel consumption was identified to be the predominant source of PAHs over Hexi Corridor, accounting for 43 % of the concentration of total (15) PAHs. Backward and forward trajectory and cluster analysis were also carried out to identify potential origins of PAHs monitored at several urban and rural sites. Lung cancer risk of local residents to gas phase PAHs via inhalation exposure throughout the province was found to be around a critical value of the lung cancer risk level at 10(-6) recommended by the U.S. EPA risk assessment guideline.

Passive air sampling for semi-volatile organic chemicals

“…Studies involving networks of PASs in a region are also very common and have been conducted around the world (Table 15). A region can be an administrative unit, such as a Chinese province 251,[346][347][348] or an Italian region [349][350][351] or it could be a country's coastal area [352][353][354][355] or an entire or partial watershed. [356][357][358][359] These types of studies have almost exclusively relied upon the PUF-PAS, with a few exceptions.…”

“…Accordingly, numerous PAS studies have sought to estimate inhalation exposure and the health risk associated with exposure to airborne PAHs. 336,348,[361][362][363]439,526 This is typically done by summing the products of the concentration of carcinogenic PAHs with their relative potency factors in order to obtain an equivalent concentration of benzo[a]pyrene, which in turn can be converted into a chronic daily inhalation intake rate. Sometimes, a value for the cancer risk due to inhalation is derived as well.…”

Revealing the Efficacy of Thermostable Biosurfactant in Heavy Metal Bioremediation and Surface Treatment in Vegetables

“…Metals accumulate in the environment as the by-product of anthropogenic developmental activities such as tanneries, manufacturing of arms and ammunition, paint, metal pipes, batteries, mining, etc. (Singh and Cameotra, 2004), and their high accumulation can lead to serious intoxication (Mao et al, 2016). Heavy metal accumulations in the environment are persistent to degradation, but can be converted to less toxic forms (Santona et al, 2006).…”