The concentration of airborne microplastics is largely unknown in the remote high mountain area of the Tibetan Plateau. Here we report airborne microplastic concentrations of 2.5–58.8 n/m3 in urban, rural and wildland areas across the Tibetan Plateau, with smaller (∼89% <100 µm) fragments (>80%) dominating. Polyethylene terephthalate, polyethylene, polyamide and polystyrene were the dominant polymers of airborne microplastics on the Tibetan Plateau. Distribution of airborne microplastics was positively correlated with anthropogenic activity indices, such as population density and nighttime light intensity. Although the contribution of long-range atmospheric transport is valid, dispersed villages also appear to be a source of airborne microplastics for wildland areas across the Tibetan Plateau.

The ubiquitous occurrence of micro/nano plastics (MNPs) poses potential threats to ecosystem and human health that have attracted broad concerns in recent decades. Detection of MNPs in several remote regions has implicated atmospheric transport as an important pathway for global dissemination of MNPs and hence as a global health risk. In this review, the latest research progress on (1) sampling and detection; (2) origin and characteristics; and (3) transport and fate of atmospheric MNPs was summarized. Further, the current status of exposure risks and toxicological effects from inhaled atmospheric MNPs on human health is examined. Due to limitations in sampling and identification methodologies, the study of atmospheric nanoplastics is very limited today. The large spatial variation of atmospheric MNP concentrations reported worldwide makes it difficult to compare the overall indoor and outdoor exposure risks. Several in vitro, in vivo, and epidemiological studies demonstrate adverse effects of immune response, apoptosis and oxidative stress caused by MNP inhalation that may induce cardiovascular diseases and reproductive and developmental abnormalities. Given the emerging importance of atmospheric MNPs, the establishment of standardized sampling -pretreatment -detection protocols and compre- hensive toxicological studies are critical to advance environmental and health risk assessments of atmospheric MNPs.

Human-health risks from microplastics have attracted considerable attention, but little is known about human exposure pathways and intensities. Recent studies posited that inhalation of atmospheric microplastics was the dominant human-exposure pathway. Herein, our study identified that atmospheric microplastics ingested from deposition during routine dining/drinking activities represent another important exposure pathway. We measured abundances of atmospheric-deposited microplastics of up to 10(5) items m(-2) d(-1) in dining/drinking venues, with 90% smaller than 100 mu m and a dominance of amorphous fragments rather than fibers. Typical work-life scenarios projected an annual ingestion of 1.9 x 10(5) to 1.3 x 10(6) microplastics through atmospheric deposition on diet, with higher exposure rates for indoor versus outdoor dining/drinking settings. Ingestion of atmospheric-deposited microplastics through diet was similar in magnitude to presumed inhalation exposure, but 2-3 orders of magnitude greater than direct ingestion from food sources. Simple mitigation strategies (e.g., covering and rinsing dishware) can substantially reduce the exposure of atmospheric deposition microplastics through diet.

溶解氧(DO)是调控地表水水质、维持水生生态系统健康的关键因子.当前我国许多河流因有机污染而出现缺氧现象,因此,曝气就成为水体治理和生态修复的一种常用手段.光照、温度等环境因子的昼夜变化能够显著影响水体的自然复氧过程,曝气与日间和夜间的自然复氧过程相叠加时可能产生不同的耦合效果.本研究以典型平原河网水系某河流为研究对象,分别在日间曝气、夜间曝气模式下,对河流表、底层溶解氧等水质指标进行多日连续监测,以研究不同曝气节律对河流的复氧效果.结果显示,日间曝气对夏季河流水体补氧贡献不显著,且夜间停止曝气后水体出现了显著的缺氧状况.夜间曝气对水体的补氧效果较好,结合昼间水体的自然复氧,能够全日避免水体出现缺氧情况.本研究表明,在了解水体自然复氧能力的基础上合理地结合夜间曝气,将可能获得更加高效的曝气方案.

Microplastics (MPs) in marine and terrestrial environments have been intensively studied, but the dynamics of airborne MPs remains limited. Existing studies on atmospheric MPs are mostly derived from collection of atmospheric deposition, whereas direct measurements of airborne MPs are scarce. However, the abundance of airborne MPs is more relevant for evaluating human inhalation exposure risk. Herein, airborne MPs in indoor and outdoor environments from urban and rural areas of a coastal city in eastern China were investigated. MP concentrations (mean±SD) in indoor air (1583 ± 1180 n/m3) were an order of magnitude higher than outdoor air (189 ± 85 n/m3), and airborne MP concentrations in urban areas (224 ± 70 n/m3) were higher than rural areas (101 ± 47 n/m3). MPs smaller than 100 µm dominated airborne MPs, and the predominant shape of airborne MPs was fragments, as opposed to fibers. The larger MP size fractions contained a higher proportion of fibers, whereas the smaller size fractions were nearly exclusively composed of fragments. The health risk caused by ubiquitous airborne MPs should not be discounted as the maximum annual outdoor exposure of airborne MPs can reach 1 million/year, while indoor exposure may be even higher due to higher indoor airborne MP concentrations.

Airborne microplastics (MPs) are receiving increasing attention due to their ubiquitous nature and the potential human health consequences resulting from inhalation. The limited data for airborne MP concentrations vary widely among studies (∼4 orders of magnitude), but comparisons are tenuous due to the inconsistent collection and detection/enumeration methodologies among studies. Herein, we used uniform methodologies to obtain comparable airborne MP concentration data to assess MP exposure intensity in five Chinese megacities. Airborne MP concentrations in northern cities (358 ± 132 items/m3) were higher than those in southeast cities (230 ± 94 items/m3) but of a similar order of magnitude, unlike previous studies. The majority (94.7%) of MPs found in air samples were smaller than 100 μm, and the main shape of airborne MPs was fragments (88.2%). Polyethylene, polyester, and polystyrene were the dominant polymers comprising airborne MPs. No consistent relationships were detected between airborne MP concentration and typical socioeconomic indices, and the spatial and diurnal patterns for airborne MPs were different from various components of air quality indices (PM2.5, PM10, etc.). These findings reflect the contrasting source/generation dynamics between airborne MPs and other airborne pollutants. Maximum annual exposure of humans to airborne MPs was estimated in the range of 1-2 million/year in these megacities, highlighting the need for additional research examining the human health risks from the inhalation of airborne MPs.

平原河网地区水污染治理难度比较大,如何巩固治水成果也是一个难题.在温瑞塘河主河道设置6个水质监测点,于2018年对主要水质项目pH值、 高锰酸盐指数(KMnO4)、 氨氮(NH3-N)、 总磷(TP)和溶解氧(DO)进行逐月监测.结果表明,研究河段TP、KMnO4、NH3-N和DO的年均值分别为0.16、1.50、2.45、5.32 mg·L-1,对照 《地表水环境质量标准》(GB 3838—2002),分别符合Ⅲ类、 Ⅲ类、 Ⅱ类和Ⅲ类水质要求.该河段已从整体上消除了劣Ⅴ类水体,目前的主要污染物是NH3-N.该河道水质的空间变异性和季节变异性均不显著.防止水质反弹将是未来的工作重点之一.针对平原河网水质的水污染防治,提出坚持连片治理、坚持水陆共治、 注重生态恢复、 完善长效机制的对策建议.

地表直接径流和基流均是流域非点源氮/磷养分输出的重要水文途径.科学认识和定量模拟基流氮/磷养分输出对于准确解析水源地水体非点源污染来源至关重要.基于Load Estimator模型和数字滤波算法,建立了定量水源地基流氮素输出的方法体系.以浙江省珊溪水源地的玉泉溪流域为例,利用玉泉溪2010-01-2013-12期间逐月总氮(TN)水质监测数据和逐日流量数据,展示了该方法的计算过程.结果表明,本文建立的水源地基流氮素输出定量方法结果合理,模拟精度高,决定系数和纳什系数分别为0.83和0.80;玉泉溪流域2010-2013年TN负荷量为141.21～274.68 t·a-1,平均208.63 t·a-1,年基流TN负荷量为84.39～168.68t·a-1,平均127.69 t·a-1;基流对玉泉溪年均TN负荷量贡献率高达60％以上,流域基流养分输出对地表水体的污染应引起足够重视.

新型冠状病毒肺炎的疫情发生以及快速传播,使公共卫生应急管理再次引起人们的关注.这次疫情既展现了公共卫生应急管理的重要性,也暴露了防治过程中存在的弊端.本文围绕公共卫生应急管理通过法律法规手段、行政管理手段、医疗技术手段、预防宣教手段在新型冠状病毒肺炎疫情中的应用,提出公共卫生应急管理优化策略,助力全国各省疫情防控工作,科学精准打赢疫情持久战,推进我国公共卫生应急管理事业的发展.

In recent years, there is great concern about plastic pollution due to the identification of several environmental risks associated with microplastics (< 5 mm). This study investigated microplastic and macroplastic accumulation patterns in a newly formed Spartina alterniflora colonized saltmarsh of an estuary in southeastern China. Abundance of microplastic and macroplastic particles was in the range of 9600-130725 and 200-4350 n/m(2), respectively. Abundances of microplastics and macroplastics were highest at the saltmarsh edge, but the mass of macroplastics was highest in the saltmarsh interior. Mass of microplastics and macroplastics in bareflats was significantly lower than vegetated areas. Although microplastics accounted for 96.3% of total plastic abundance, macroplastics accounted for 90% of total plastic mass. Results showed that S. alterniflora dominated saltmarshes have a strong ability to trap plastic debris, especially macroplastics. Thus, coastal saltmarshes may serve as a transformer of macroplastics to microplastics and consequently as a source of microplastics to the ocean.