State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210046, People's Republic of China.
State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210046, People's Republic of China.
Environ Int. 2016 Sep;94:69-75. doi: 10.1016/j.envint.2016.05.010. Epub 2016 May 19.
Pollution controls were implemented to improve the air quality for the 2014 Youth Olympic Games (YOG) in Nanjing. To investigate the influence of pollution control on Pb inhalation bioaccessibility in PM2.5, samples were collected before, during, and after YOG. The objectives were to identify Pb sources in PM2.5 using stable isotope fingerprinting technique and compare Pb inhalation bioaccessibility in PM2.5 using two simulated lung fluids. While artificial lysosomal fluid (ALF) simulates interstitial fluid at pH 7.4, Gamble's solution simulates fluid in alveolar macrophages at pH 4.5. The Pb concentration in PM2.5 samples during YOG (88.2ngm(-3)) was 44-48% lower than that in non-YOG samples. Based on stable Pb isotope ratios, Pb in YOG samples was mainly from coal combustion while Pb in non-YOG samples was from coal combustion and smelting activities. While Pb bioaccessibility in YOG samples was lower than those in non-YOG samples (59-79% vs. 55-87%) by ALF, it was higher than those in non-YOG samples (11-29% vs. 5.3-21%) based on Gamble's solution, attributing to the lower pH and organic acids in ALF. Different Pb bioaccessibility in PM2.5 between samples resulted from changes in Pb species due to pollution control. PbSO4 was the main Pb species in PM2.5 from coal combustion, which was less soluble in ALF than PbO from smelting activities, but more soluble in Gamble's solution. This study showed it is important to consider Pb bioaccessibility during pollution control as source control not only reduced Pb contamination in PM2.5 but also influenced Pb bioaccessibility.
为了改善 2014 年青奥会期间南京的空气质量，实施了污染控制措施。本研究旨在调查污染控制对 PM2.5 中 Pb 吸入生物可给性的影响，为此采集了青奥会前、期间和后三个阶段的 PM2.5 样品。采用稳定同位素指纹技术确定 PM2.5 中 Pb 的来源，并使用两种模拟肺液比较 PM2.5 中 Pb 的吸入生物可给性。人工溶酶体液（ALF）模拟 pH7.4 时的细胞间液，而 Gamble 溶液模拟 pH4.5 时肺泡巨噬细胞中的液体。青奥会期间 PM2.5 样品中的 Pb 浓度（88.2ngm(-3))比非青奥会期间低 44-48%。基于稳定的 Pb 同位素比值，青奥会期间 PM2.5 中的 Pb 主要来源于煤炭燃烧，而非青奥会期间 PM2.5 中的 Pb 则来自煤炭燃烧和冶炼活动。ALF 模拟结果表明，青奥会期间 PM2.5 中 Pb 的生物可给性（59-79%）低于非青奥会期间（55-87%），而 Gamble 溶液模拟结果表明，青奥会期间 PM2.5 中 Pb 的生物可给性（11-29%）高于非青奥会期间（5.3-21%），这是由于 ALF 中 pH 值较低且含有机酸。污染控制导致 Pb 形态发生变化，进而引起 PM2.5 中 Pb 生物可给性的差异。来源于煤炭燃烧的 PM2.5 中主要的 Pb 形态为 PbSO4，其在 ALF 中的溶解度低于来自冶炼活动的 PbO，但在 Gamble 溶液中的溶解度更高。综上所述，污染控制不仅降低了 PM2.5 中的 Pb 污染，还影响了 Pb 的生物可给性，因此在进行污染控制时，考虑 Pb 生物可给性非常重要。
