A typical Printed Circuit Board（PCB） manufacturer was chosen as the object of this study.During PCB processing, fine particulate matter and heavy metals（Cu, Zn, Pb, Cr, Cd and Ni）will be released into the air and dust, which then impact workers＇ health and the environment. The concentrations of total suspended particle（TSP）, PM10 and PM2.5in the off-site were 106.3, 90.0 and 50.2 μg/m3, respectively, while the concentrations of TSP, PM10 and PM2.5in the workshops ranged from 36.1 to 365.3, from 27.1 to 289.8 and from 22.1 to212.3 μg/m3, respectively. Almost all six of the heavy metals were detected in all of the particle samples except Cd. For each workshop, it was obvious that Zn was the most enriched metal in TSP, followed by Cu 〉 Pb（Cr） 〉 Ni 〉 Cd, and the same trend was found for PM10 and PM2.5. In the dust samples, Cu（which ranged from 4.02 to 56.31 mg/g） was the most enriched metal, followed by Zn, Cr, Pb, Ni and Cd, and the corresponding concentrations ranged from 0.77 to 4.47, 0.37 to 1.59, 0.26 to 0.84, 0.13 to 0.44 and nd to0.078 mg/g, respectively. The health risk assessment showed that noncancerous effects are unlikely for Zn, Pb, Cr, Cu, Cd and Ni. The carcinogenic risks for Cd and Ni were all lower than 10-6, except for Cr. This result indicates that carcinogenic risks for workers are relatively possible in the workshops. These findings suggest that this technology is advanced from the perspective of environmental protection in the waste PCB＇s recycling industry.
Peng ZhouJie GuoXiaoyu ZhouWei ZhangLili LiuYangcheng LiuKuangfei Lin
As a new class of xenogenous nanoparticle, quantum dots （QDs） possess the potential to co-exist with Cu^2＋ in human liver. The combined toxicity is thus concerned. Considering QDs and Cu^2＋ are known ROS （reactive oxygen species） inducer, we investigated the combined oxidative stress and corresponding protective strategy using human hepatic L02 cells. The results demonstrated that the presence of a small amount of MPA-CdTe QDs （2 μg/mL） in a Cu^2＋ solution （2.5-20 μg/mL） resulted in a higher toxicity with up to 8-fold cell viability decrease, which was accompanied by cell morphology changes. The combined toxicity was then confirmed as ROS associated oxidative stress with up to 300% and 35% increase of the intracellular ROS level and glutathione S-transferase （GST） activity, respectively. N-acetylcysteine （NAC） can also provide almost complete protection against the induced toxicity. Therefore, the ROS associated oxidant injury might be responsible for the QDs-Cu^2＋/Cu^2＋ induced toxicity and could be balanced through cytoprotective antioxidant enzyme GST.
Yuxia Zhao,Kuangfei Lin,Wei Zhang,Lili Liu State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process,Shanghai 200237,China
