In Vitro investigations of high molecular weight polycyclic aromatic hydrocarbons in winter airborne particles using simulated lung fluids

Abstract

This study evaluated the bioaccessibility of 9 high molecular weight polycyclic aromatic hydrocarbons (PAH9) in airborne particulate matter (PM) by employing a physiological extraction test with simulated lung fluids [Gamble's solution and artificial lysosomal fluid (ALF)]. Airborne PM samples (PM2.5) were collected during the non-heating and heating periods in Harbin, a city in Northeast China. All PAH9 were detectable in the PM2.5 fractions. Indeno[1,2,3-c,d]pyrene (Ind), benzo[a]pyrene (BaP) and benzo[b]fluoranthene (BbF) were the most common PAH9 species detected. After Gamble's solution extraction, PM2.5-bound PAH9 bioaccessibility was significantly higher (p < 0.05) compared to its after ALF extraction. We estimated the lifetime excess inhalation cancer risks per million people owing to exposure to total PAH9 to be 29.1–69.8 and 141–477 cancer cases per million people during the non-heating and heating periods, respectively, while these numbers were reduced to 1.90–11.3 and 5.90–32.8 after Gamble's solution extraction (decreases of 90.7% and 92.7%) and 2.10–7.00 and 2.80–19.9 after ALF extraction (decreases of 92.6% and 97.3%). Predictions of pulmonary toxicity caused by airborne PM upon inhalation might be overestimated if the bioaccessibility and potential toxicity of PM2.5-bound PAH9 are not fully evaluated.