Levels and ecological and health risk assessment of PM2.5-bound heavy metals in the northern part of the Persian Gulf

Bushehr, a port along the northern part of the Persian Gulf, has repeatedly encountered dust storms in recent years but there is not been a comprehensive study on the PM 2.5 contents in this region. The present study reports the characteristics and health risks of atmospheric PM 2.5 -bound heavy metals (HMs) in Bushehr from December 2016 to September 2017. A total of 46 samples were analyzed, and a high volume air sampler equipped with quartz fiber filters was used for sampling. Inductively coupled plasma optical emission spectroscopy (ICP-OES) was also used for HMs analyses. Risk assessment and hazard index (HI) of these metals were computed by using USEPA’s exposure parameters. The results showed that the average 24-h mass concentration of PM 2.5 ranged from 22.09 to 292.45 μg/m 3 . The results also indicated that 95.65 and 82.61% of the samples were higher than WHO and EPA guidelines for 24-h PM 2.5 . Also there was no statistically significant relationship between wind direction and PM 2.5 .The average concentration levels of seven measured metals (Cd, Co, Cr, Fe, Ni, Pb, and V) in the PM 2.5 samples were in the range of 6.03 ng/m 3 to 1335.94 ng/m 3 , and the order of their concentration was Fe > Ni > Pb > Cr > Cd > V > Co. Principal component analysis (PCA) showed that PM 2.5 -bound heavy metals were categorized in three groups. The ecological risk level of calculated metals was very significant, and the major contribution of the ecological risk was related to Cd. The highest HQ in children and adults was related to Cr, and overall HI in children was higher than adults. Also the RI values of Cr in both groups of children and adults were indicated high risk of developing cancer in human.