Routes of exposure include inhalation, ingestion, and dermal contact in both occupational and non-occupational settings. PAHs are widely distributed in the atmosphere, and they can pose adverse health effects to human beings because of their well-known carcinogenic, mutagenic, and teratogenic properties that lead to increased human health risks. Heavier PAHs (more than 4 rings) tend to adsorb PM, while lighter PAHs (less than 4 rings) tend to retain gaseously and will be removed via precipitation. PAHs originated from three sources 1.petrogenic sources that are caused by fossil and petroleum fuels and often have 2 to 3 aromatic rings or the same PAH with low molecular weight (LMWPAHs) that are mostly concentrated in the vapor phase, 2.pyrogenic, which is caused by incomplete combustion of fuels and is called as compounds with higher aromatic ring (≥ 4) or PAH with high molecular weight (HMWPAHs)and potentially accumulate in the particle phase, 3.natural PAHs that are produced by biological processes and usually do not affect human health in environmental exposure levels and are not considered, and short-term environmental exposures to petrogenic and pyrogenic PAHs can lead to tissue irritation (e.g., skin, respiratory, eyes, gastrointestinal). Although PAHs are naturally produced by forest fires and volcanoes, most of the PAHs present in the ambient air are the result of man-made processes. PAHs are a natural component of most fossil fuels. Polycyclic aromatic hydrocarbons (PAHs) have received particular care, because of their wide distribution in the atmosphere. Therefore, considering the various sources of air pollutants and its role on people’s health, decision makers should adopt appropriate policies on air quality to reduce the ambient air PAHs and to mitigate human exposure.Īirborne particulate matter in urban environments can be divided into coarse particles, d ≤ 10 µm (PM 10), and fine particles, d ≤ 2.5 µm (PM 2,5), which shows a mixture of both organic and inorganic materials. The total cancer risk values as a result of exposure to PAHs in ambient air PM 10 in all three cities for children and adults and in both cold and warm seasons were between 1 × 10 − 6 and 1 × 10 − 4, and this indicates a potential carcinogenic risk.
The results showed that the total PAHs concentration in the cold and warm seasons was dependent on industrial activities, particularly the neighboring petrochemical units of the city, vehicular exhausts, traffic and use of oil, gas, and coal in energy production. The most abundant PAHs species were Pyr, Chr, B P, and Flt.
The high molecular weight PAHs were the most predominant components. The Σ16 PAHs concentration in ambient air PM 10 during the cold season in Ahvaz, Abadan and Asaluyeh was 244.6, 633, and 909 ng m − 3, respectively, and during the warm season in Ahvaz, Abadan, and Asaluyeh was 242.1, 1570 and 251 ng m − 3, respectively. The mean concentrations of PM 10 in two warm and cold seasons in Ahvaz were higher and in Abadan and Assaluyeh were lower than the national standard of Iran and the guidelines of the World Health Organization. This study investigates the concentrations of PM 10-bound PAHs and their seasonal variations in three cities of Ahvaz, Abadan, and Asaluyeh in Iran.
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