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

This study evaluated the bio accessibility of 9 high molecular weight polycyclic aromatic hydrocarbons (PAH(9)) in airborne particulate matter (PM) by employing a physiological extraction test with simulated lung fluids [Gambles 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 PAH(9) were detectable in the PM(2.5 )fractions. Indeno[1,2,3-c,d]pyrene (Ind), benzo[a]pyrene (BaP) and benzo[b]fluoranthene (BbF) were the most common PAH(9) species detected. After Gambles solution extraction, PM2.5 -bound PAH(9) bio accessibility 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 PAH(9) 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 Gambles 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 PAH(9) are not fully evaluated.