Wang Wenhua, Shao Longyi, Li Xian, Li Yaowei, Lyu Ruihe, Zhou Xiuyan
School of Resources and Civil Engineering, Northeastern University, Shenyang, 110819, China; School of Resources and Materials, Northeastern University at Qinhuangdao, Qinhuangdao, 066004, China.
State Key Laboratory of Coal Resources and Safe Mining & College of Geosciences and Surveying Engineering, China University of Mining and Technology, Beijing, 100083, China.
Environ Pollut. 2023 Oct 15;335:122288. doi: 10.1016/j.envpol.2023.122288. Epub 2023 Aug 4.
Dust storms are one of the largest sources of non-exhaust emissions in China, which can adversely affect air quality and human health during long-distance transportation. To study the influence of dust storms on aerosol particle composition, samples of fine aerosol (PM) were collected before, during, and after the severe dust storm episodes in a coastal city of North China. Then the water-soluble inorganic ions in the filters were analyzed. The results showed that the chemical composition varied significantly in different sampling periods. Before the dust storm periods (Phase 1), the weather was characterized by high relative humidity. NO was the main water-soluble inorganic ion, accounting for about 1/3 of the total mass of PM, which is very different from the situation a few years ago when sulfate was the dominant. The results indicated that the chemical composition of the atmosphere in China has changed significantly after the implementation of strict air pollution control measures. During the severe dust storm periods (within a few hours after the dust invasion, Phase 2), the proportion of Ca in PM was high; the sulfate formation was limited due to adiabatic air mass affected by the cold front, and the sulfate content might be mainly from desert soil. However, a small amount of nitrate can be formed during their long-distance transportation. After the dust storm periods (Phase 3), dust plums and local polluted air mass mixed well. The proportion of secondary inorganic ions increased, and nitrate formation was still the main. The changes in the chemical composition from a few years ago during Phase 1 and the sharp changes in different water-soluble inorganic ions during different Phases should be carefully considered to evaluate their implications for air quality and human health.
沙尘暴是中国非尾气排放的最大来源之一，在长距离传输过程中会对空气质量和人体健康产生不利影响。为研究沙尘暴对气溶胶颗粒成分的影响，在中国北方沿海城市的严重沙尘暴事件发生前、期间和之后采集了细气溶胶（PM）样本。然后对滤膜中的水溶性无机离子进行了分析。结果表明，不同采样时期化学成分差异显著。在沙尘暴时期之前（阶段1），天气特征是相对湿度较高。NO是主要的水溶性无机离子，约占PM总质量的1/3，这与几年前以硫酸盐为主的情况有很大不同。结果表明，中国实施严格的空气污染控制措施后，大气化学成分发生了显著变化。在严重沙尘暴时期（沙尘侵入后的几小时内，阶段2），PM中Ca的比例较高；受冷锋影响的绝热气团限制了硫酸盐的形成，硫酸盐含量可能主要来自沙漠土壤。然而，在其长距离传输过程中会形成少量硝酸盐。在沙尘暴时期之后（阶段3），沙尘羽流与当地污染气团充分混合。二次无机离子比例增加，硝酸盐形成仍然是主要的。应仔细考虑阶段1中与几年前相比化学成分的变化以及不同阶段不同水溶性无机离子的急剧变化，以评估它们对空气质量和人体健康的影响。
