宜昌城区霾与非霾天气下PM2.5中12种元素污染特征比较

目的 了解宜昌城区霾与非霾天气下PM_2.5中元素污染特征,为本地区雾霾天气对人体健康效应的研究以及环保调控措施的制定提供科学依据。 方法 2016年12月－2017年11月利用中流量采样器采集大气中PM_2.5,电感耦合等离子体质谱检测铍、铝、铬、锰、镍、砷、硒、镉、锑、汞、铊和铅含量后,对12种元素霾与非霾天气下的差异进行比较。 结果 宜昌市大气中PM_2.5质量浓度的年均值为56.4 μg/m³,呈冬季(94.0 μg/m³)>春季(50.6 μg/m³)>秋季(36.6 μg/m³)>夏季(28.1 μg/m³)趋势;12种元素中污染水平最高的是铝(141.2 ng/m³),其次依次是铅(37.8 ng/m³)、锰(25.3 ng/m³)、砷(5.29 ng/m³)等。检测的12种元素占PM_2.5质量浓度的0.393%,非霾日(0.555%)高于霾日(0.232%)。 结论 宜昌市大气中PM_2.5污染情况较以往有所改善,但砷、铬、铅等金属污染应当予以重视。

Comparison of characteristics of twelve elements in PM2.5 during haze and non-haze episodes in urban areas of Yichang City

Objective To investigate the pollution characteristics of elements in atmospheric fine particles (PM_2.5) in haze and non-haze episodes in urban areas of Yichang City, and to provide a scientific basis for estimating the PM_2.5 health effects in local areas and developing environmental protection measures. Methods PM_2.5 samples were collected by a sampler of medium-flow capacity from December 2016 to November 2017. The contents of elements, including beryllium, aluminum, chromium, manganese, nickel, arsenic, selenium, cadmium, stibium, mercury, thallium and lead were detected by inductively coupled plasma-mass spectrometry (ICP-MS), and then the differences in mass concentration of the twelve elements between haze and non-haze episodes were compared. Results The annual mean concentration of PM_2.5 in urban areas of Yichang City was 56.4 μg/m³, showing a tendency of winter (94.0 μg/m³) > spring(50.6 μg/m³) > autumn (36.6 μg/m³) > summer(28.1 μg/m³). The pollution level of aluminum (141.2 ng/m³) was the most serious, followed by lead(37.8 ng/m³), manganese (25.3 ng/m³) and arsenic (5.29 ng/m³). The detected twelve elements accounted for 0.393% of PM_2.5 mass concentration, and their proportion in PM_2.5 mass concentration in non-haze days was significantly higher than that in haze days (0.555% vs. 0.232%). Conclusions The condition of PM_2.5 pollution in the atmosphere in Yichang City has been improved, but heavy metal pollution such as arsenic, chromium and lead should be taken seriously.