Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resources and Environmental Science, China Agricultural University, Beijing 100193, China.
Analysis and Testing Center, Beijing Normal University, Beijing 100875, China.
Sci Total Environ. 2024 Oct 10;946:174129. doi: 10.1016/j.scitotenv.2024.174129. Epub 2024 Jun 23.
Metal pollutants in fine particulate matter (PM) are physiologically toxic, threatening ecosystems through atmospheric deposition. Biotoxicity and bioavailability are mainly determined by the active speciation of metal pollutants in PM. As a megacity in China, Beijing has suffered severe particulate pollution over the past two decades, and the health effects of metal pollutants in PM have received significant attention. However, there is a limited understanding of the active forms of metals in PM and their ecological risks to plants, soil or water in Beijing. It is essential that the ecological risks of metal pollutants in PM are accurately evaluated based on their bioavailability, identifying the key pollutants and revealing historic trends to future risks control. A two-year project measured the chemical speciation of pollution elements (As, Cd, Cu, Cr, Ni, Mn, Pb, Sb, Sr, Ti, and Zn) in PM in Beijing, in particular their bioavailability, assessing ecological risks and identifying key pollutants. The mass concentrations of total and active species of pollution elements were 199.12 ng/m and 114.97 ng/m, respectively. Active fractions accounted for 57.7 % of the total. Cd had the highest active proportion. Based on the risk assessment code (RAC), most pollution elements except Ti had moderate or high ecological risk, with RAC exceeding 30 %. Cd, with an RAC of 70 %, presented the strongest ecological risk. Comparing our data with previous research shows that concentrations of pollution elements in PM in Beijing have decreased over the past decade. However, although the total concentrations of Cd in PM have decreased by >50 % over the past decade, based on machine model simulation, its ecological risk has reduced by only 10 %. Our research shows that the ecological risks of pollution elements remain high despite their decreasing concentrations. Controlling the active species of metal pollutants in PM in Beijing in the future is vital.
金属污染物在细颗粒物（PM）中具有生理毒性，通过大气沉积对生态系统构成威胁。生物毒性和生物利用度主要取决于 PM 中金属污染物的活性形态。作为中国的一个特大城市，北京在过去二十年中遭受了严重的颗粒物污染，PM 中金属污染物的健康影响受到了广泛关注。然而，对于北京 PM 中金属的活性形态及其对植物、土壤或水的生态风险，人们的了解有限。基于生物利用度准确评估 PM 中金属污染物的生态风险，确定关键污染物并揭示历史趋势对未来风险控制至关重要。一个为期两年的项目测量了北京 PM 中污染元素（As、Cd、Cu、Cr、Ni、Mn、Pb、Sb、Sr、Ti 和 Zn）的化学形态，特别是它们的生物利用度，评估了生态风险并确定了关键污染物。污染元素的总浓度和活性浓度分别为 199.12ng/m 和 114.97ng/m。活性分数占总分数的 57.7%。Cd 的活性比例最高。根据风险评估代码（RAC），除 Ti 外，大多数污染元素都具有中等或高生态风险，RAC 超过 30%。Cd 的 RAC 为 70%，具有最强的生态风险。将我们的数据与以前的研究进行比较表明，过去十年北京 PM 中污染元素的浓度有所下降。然而，尽管过去十年 PM 中 Cd 的总浓度下降了超过 50%，但根据机器模型模拟，其生态风险仅降低了 10%。我们的研究表明，尽管浓度下降，污染元素的生态风险仍然很高。未来控制北京 PM 中金属污染物的活性形态至关重要。
