Hazard posed by metals and As in PM2.5 in air of five megacities in the Beijing-Tianjin-Hebei region of China during APEC.

Airborne fine particulate matter (PM2.5) from five megacities including Beijing, Tianjin, Shijiazhuang, Baoding, and Jinan were collected during November 2014 and compared with similar periods in 2012 and 2013. The November 2014 period coincided with the Asia Pacific Economic Cooperation (APEC) Leaders Meeting during which measures to control pollution of the air were introduced. Concentrations of 11 elements in PM2.5 were quantified by inductively coupled plasma-mass spectrometry (ICP-MS) after microwave-assisted digestion. Potential effects of five toxic trace metals including Mn, Ni, Cu, Zn, Pb, and the metalloid As on health were assessed. In 2014, concentrations of PM2.5 were significantly less than during the same period in 2012 and 2013. Mean concentrations of six elements ranked in decreasing order, Zn > Pb > Cu ≈ Mn > As > Ni, and spatial concentrations ranked in decreasing order, Shijiazhuang > Baoding > Tianjin > Jinan > Beijing. Risks of the five metals and the metalloid As to health of humans were small, except for Mn in Shijiazhuang. Risks to health posed by other elements were less during the period of study. Risks posed by the five metals and As in Beijing were greater to varying degrees after the APEC meeting. Risks to health of humans during the APEC were overall lesser than the same period in 2012 and 2013, mostly due to lesser emissions due to the short-term control measures.