Determination and source identification of priority polycyclic aromatic hydrocarbons in PM2.5 in Taiyuan, China

- We analyzed PAHs in PM2.5 in Taiyuan (China) over a year.
- Results show strong seasonal variation, with highest values in winter.
- The frequency of PAHs was as follows: 4-ring > 6-ring > 5-ring > 3-ring.
- Main PAH sources are combustion and vehicle emissions.
- The ranking of ILCR in decreasing order was as follows: winter, spring, autumn, and summer.
- The loss of life expectancy for male and female adults is higher in winter.

Sixteen polycyclic aromatic hydrocarbons (PAHs) present in PM2. 5 were analyzed in 2012 in Taiyuan (China) using high performance liquid chromatography (HPLC) with fluorescence and ultraviolet detectors. The average daily mass concentrations of ΣPAHs in different seasons ranged from 10.36 ng/m3 to 215.93 ng/m3 and had strong seasonal variation, with highest values in winter and lowest in summer. Over the whole year, PAHs appeared in the following order of frequency: 4-ring > 6-ring > 5-ring > 3-ring; in winter, the percentage of 4-ring PAHs was the highest (62.68%), while in summer, the percentages of 5-ring and 6-ring PAHs (cumulative total of 50.57%) were higher. The ratio method was employed to investigate potential source categories of PAHs in PM2.5 in Taiyuan, with data suggesting that the main PAH sources are coal and wood combustion and vehicle emissions. Finally, a risk assessment of PAHs was performed based on benzo(a)pyrene equivalent (BaPeq) values and individual cancer risk ratios, with results suggesting that the toxicity of PAHs was high during winter and spring time in Taiyuan. The values of incremental lifetime cancer risk (ILCR) induced by whole year inhalation exposure(Ri) for all age groups were larger than 10− 6 in spring and winter, while Ri values for male and female adults in summer and autumn were also larger than 10− 6, indicating high potential carcinogenic risk. During the same season, the ILCR of adults was greater than that of other age groups and that of females was a little higher than of males. With respect to the season, the ranking of ILCR in decreasing order was as follows: winter, spring, autumn, and summer.