Carcinogenic risks of particulate matter during Middle Eastern dust events and normal days

Özet

This study evaluated and compared the carcinogenic risks due to inhalation exposure to particulate matter with an aerodynamic diameter below 10 μm (PM10) during dust and normal days in Ahvaz, Iran. PM10 was sampled every 6 day during a one-year period, with additional sampling during dust episodes (total = 84). The concentrations of arsenic, cadmium, chromium, nickel, and lead were determined using acidic digestion followed by analysis with inductively coupled plasma optical emission spectrometry (ICP-OES). Excess life-time carcinogenic risk (ELCR) of exposure to PM-bound heavy metals was estimated using inhalation unit risk (IUR) approach and a Monte Carlo simulation. The sum of carcinogenic risks of all five heavy metals on both dust (1.61 × 10−5) and non-dust (9.49 × 10−6) days exceeded the US EPA's risk limit (1 × 10−6). Chromium assuming Cr(VI) and arsenic risks were higher than those from the other heavy metals. The average of carcinogenic risks in summer and winter were 1.59 × 10−5 and 1.81 × 10−5, respectively. These results indicated that although dust events are short-term, acute episodes, their high frequency in some affected areas such as Ahvaz can increase the lifetime cancer risk.