Characteristics and fate behavior of environmentally persistent free radicals in atmospheric particulate matter

Background,aim,and scope Environmentally persistent free radicals(EPFRs)have received significant attention due to their longer lifetime and stable existence in various environments.The strong environmental migration ability of particulate matter allows EPFRs to migrate over long-distance transport,thereby impacting the quality of the local atmospheric environment.Additionally,EPFRs can also adhere to atmospheric particles and interact with typical gaseous pollutants to affect atmospheric chemical reactions.EPFRs can produce some reactive organic species,promoting oxidative stress in the human body,damaging biological macromolecules and ultimately affecting the organism health.EPFRs are considered as a novel type of pollutant that affects human health.Despite their significance,there are few literatures available on the characteristics and fate behaviors of EPFRs up to date.Therefore,supplemental reviews are crucial for providing comprehensive understanding of EPFRs.Materials and methods This review summarizes the characteristics of EPFRs in particulate matter,outlines the generation mechanism and influencing factors of EPFRs,and the impacts of EPFRs on environmental quality and organism health.Results The content of EPFRs in particulate matter ranges from 1017 to 1020 spins∙g−1.Due to the strong mobility of atmospheric particulate matter,the long-term exposure to high levels of EPFRs may aggravate the impact of particulate matter on human health.The interaction between EPFRs and typical gaseous pollutants can alter their fate and influence atmospheric chemical reactions.EPFRs are mainly produced by transition metal elements and substituted aromatic hydrocarbons through electron transfer.Additionally,the chemical bond rupture of organic substances through heat treatment or ultraviolet radiation can also produce EPFRs,and heterogeneous reactions are capable producing them as well.The production of EPFRs is not only influenced by transition metal elements and precursors,but also by various environmental factors such as oxygen,temperature,light radiation,and relative humidity.Discussion EPFRs in atmospheric particulates matters are usually rich in fine particulates with obvious seasonal and regional variations.They can easily enter the human respiratory tract and lungs with inhalable particulates,thereby increasing the risk of exposure.Additionally,EPFRs in atmospheric particulates can interact with some typical gaseous pollutants,impacting the life and fate of EPFRs in the atmosphere,and alter atmospheric chemical reactions.Traditionally,EPFRs are generated by transition metal elements and substituted aromatic hydrocarbons undergoing electron transfer in the post-flame and cool-zone regions of combustion systems and other thermal processes to remove HCl,H2O or CO groups,ultimately produce semiquinones,phenoxyls,and cyclopentadienyls.Recent studies have indicated that EPFRs can also be generated under the conditions of without transition metal elemental.Organics can also produce EPFRs through chemical bond rupture during heat treatment or light radiation conditions,as well as through some heterogeneous reactions and photochemical secondary generation of EPFRs.The presence or absence of oxygen has different effects on the type and yield of EPFRs.The concentration,type,and crystal type of transition metal elements will affect the type,content,and atmospheric lifetime of EPFRs.It is generally believed that the impact of transition metal element types on EPFRs is related to the oxidation-reduction potential.The combustion temperature or heat treatment process significantly affects the type and amount of EPFRs.Factors such as precursor loading content,pH conditions,light radiation and relative humidity also influence the generation of EPFRs.EPFRs can interact with pollutants in the environment during their migration and transformation process in environmental medium.This process accelerates the degradation of pollutants and plays a crucial role in the migration and transformation of organic pollutants in environmental media.The reaction process of EPFRs may lead to the production of reactive oxygen species(ROS)such as∙OH,which can induce oxidative stress,inflammation and immune response to biological lung cells and tissues,leading to chronic respiratory and cardiopulmonary dysfunction,cardiovascular damage and neurotoxic effects,ultimately impacting the health of organisms.Conclusions The interaction mechanism between EPFRs in particulate matter and gaseous pollutants remains unclear.Furthermore,research on the generation mechanism of EPFRs without the participation of transition metals is not comprehensive,and the detection of EPFRs is limited to simple qualitative categories and lack accurate qualitative analysis.Recommendations and perspectives Further research should be conducted on the generation mechanism,measurement techniques,migration pathways,and transformation process of EPFRs.It is also important to explore the interaction between EPFRs in atmospheric particulate matter and typical gaseous pollutants.

Spatial and Temporal Variation of Particulate Matter (PM10 and PM2.5) and Its Health Effects during the Haze Event in Malaysia

This study aims to assess and compare levels of particulate matter(PM10 and PM2.5)in urban and industrial areas in Malaysia during haze episodes,which typically occur in the south west monsoon season.The high concentrations of atmospheric particles are mainly due to pollution from neighbouring countries.Daily PM concentrations were analysed for urban and industrial areas including Alor Setar,Tasek,Shah Alam,Klang,Bandaraya Melaka,Larkin,Balok Baru,and Kuala Terengganu in 2018 and 2019.The analysis employed spatiotemporal to examine how PM levels were distributed.The data summary revealed that PM levels in all study areas were right-skewed,indicating the occurrence of high particulate events.Significant peaks in PM concentrations during haze events were consistently observed between June and October,encompassing the south west monsoon and inter-monsoon periods.The study on acute respiratory illnesses primarily focused on Selangor.Analysis revealed that Klang had the highest mean number of inpatient cases for acute exacerbation of bronchial asthma(AEBA)and acute exacerbation of chronic obstructive pulmonary disease(AECOPD)with values of 260.500 and 185.170,respectively.Similarly,for outpatient cases of AEBA and AECOPD,Klang had the highest average values of 41.67 and 14.00,respectively.Shah Alam and Sungai Buloh did not show a significant increase in cases during periods of biomass burning.The statistical analysis concluded that higher concentrations of PM were associated with increased hospital admissions,particularly from June to September,as shown in the bar diagram.Haze episodes were associated with more healthcare utilization due to haze-related respiratory illnesses,seen in higher inpatient and outpatient visits(p<0.05).However,seasonal variability had minimal impact on healthcare utilization.These findings offer a comprehensive assessment of PM levels during historic haze episodes,providing valuable insights for authorities to develop policies and guidelines for effective monitoring and mitigation of the negative impacts of haze events.

Ambient Fine Particulate Matter Exposure and Blood Pressure:Evidence from a Large Chinese Multiple Follow-Up Study

Objective This study aimed to investigate the association of ambient PM_(2.5)exposure with blood pressure(BP)at the population level in China.Methods A total of 14,080 participants who had at least two valid blood pressure records were selected from the China Health and Retirement Longitudinal Survey during 2011–2015.Their long-term PM_(2.5)exposure was assessed at the geographical level,on the basis of a regular 0.1°×0.1°grid over China.A mixed-effects regression model was used to assess associations.Results Each decrease of 10μg/m^(3)in the 1 year-mean PM_(2.5)concentration(FPM1Y)was associated with a decrease of 1.24[95%confidence interval(CI):0.84–1.64]mmHg systolic BP(SBP)and 0.50(95%CI:0.25–0.75)mmHg diastolic BP(DBP),respectively.A robust association was observed between the long-term decrease in PM_(2.5)and decreased BP in the middle-aged and older population.Using a generalized additive mixed model,we further found that SBP increased nonlinearly overall with FPM1Y but in an approximately linear range when the FPM1Y concentration was<70μg/m^(3);In contrast,DBP increased approximately linearly without a clear threshold.Conclusion Efficient control of PM_(2.5)air pollution may promote vascular health in China.Our study provides robust scientific support for making the related air pollution control policies.

Impact of Urban 3D Morphology on Particulate Matter 2.5(PM2.5) Concentrations:Case Study of Beijing, China

Urban particulate matter 2.5(PM2.5)pollution and public health are closely related,and concerns regarding PM2.5 are widespread.Of the underlying factors,the urban morphology is the most manageable.Therefore,investigations of the impact of urban three-dimensional(3D)morphology on PM2.5 concentration have important scientific significance.In this paper,39 PM2.5 monitoring sites of Beijing in China were selected with PM2.5 automatic monitoring data that were collected in 2013.This data set was used to analyze the impacts of the meteorological condition and public transportation on PM2.5 concentrations.Based on the elimination of the meteorological conditions and public transportation factors,the relationships between urban 3D morphology and PM2.5 concentrations are highlighted.Ten urban 3D morphology indices were established to explore the spatial-temporal correlations between the indices and PM2.5 concentrations and analyze the impact of urban 3D morphology on the PM2.5 concentrations.Results demonstrated that road length density(RLD),road area density(RAD),construction area density(CAD),construction height density(CHD),construction volume density(CVD),construction otherness(CO),and vegetation area density(VAD)have positive impacts on the PM2.5 concentrations,whereas water area density(WAD),water fragmentation(WF),and vegetation fragmentation(VF)(except for the 500 m buffer)have negative impacts on the PM2.5 concentrations.Moreover,the correlations between the morphology indices and PM2.5 concentrations varied with the buffer scale.The findings could lay a foundation for the high-precision spatial-temporal modelling of PM2.5 concentrations and the scientific planning of urban 3D spaces by authorities responsible for controlling PM2.5 concentrations.

Human Health Risks from Exposure to Heavy Metals of Suspended Particulate Matter around the Tongon Gold Mine, Côte d’Ivoire

The Tongon mine, the largest gold mine in C?te d’Ivoire, has been in operation since April 2010. However, to our knowledge to date, no study has been conducted on metallic contamination in suspended particulate matter (PM10 and PM2.5) where there is a lack of information on the carcinogenic and non-carcinogenic risk to human health associated with the exposure of populations in the Tongon area to these pollutants. The general objective of this study is to evaluate the level of contamination of PM10;PM2.5 by heavy metals and their impact on the health of populations exposed to these pollutants in the Tongon gold mine area. The sampling and measurement of suspended particulate matter (PM10 and PM2.5) were done using a MiniVol TAS passive air sampler. Heavy metal concentrations were determined by inductively coupled plasma mass spectroscopy (Nex ION 2000 ICP-MS, USA). The results indicate that the average concentrations of suspended particles (PM2.5 and PM10) obtained are all above the recommended exposure limits. In addition, among the heavy metals contained in the suspended particles, the concentrations of arsenic and nickel are high and all above the standard limit values. The assessment of the health risks related to the inhalation of PM10 particles reveals that their inhalation over a long period could cause a carcinogenic risk.

PM2.5对代谢相关脂肪性肝病模型小鼠肝淋巴生成的影响

目的研究大气细颗粒物(particulate matter 2.5,PM2.5)暴露对C57BL/6J小鼠和代谢相关脂肪性肝病模型小鼠肝淋巴生成的影响,为防治PM2.5暴露所致肝损伤提供新靶点。方法将40只雄性C57BL/6J小鼠随机分为正常组,PM2.5组,代谢相关脂肪性肝病模型组(MAFLD组)和PM2.5-MAFLD组。MAFLD组和PM2.5-MAFLD组小鼠连续12周给予高脂饲料,其余两组给予普通饲料。从13~16周,PM2.5组和PM2.5-MAFLD组小鼠通过气管滴注法进行PM2.5染毒(每周2次);其余两组小鼠同时通过气管滴注法滴注生理盐水。末次PM2.5染毒结束24 h后将实验动物处死。测定小鼠血清丙氨酸氨基转移酶(alanine aminotransferase,ALT)和天冬氨酸氨基转移酸(aspartate aminotransferase,AST)水平;用免疫荧光染色法评估肝淋巴LYVE1表达水平;测定肝氧化应激指标(4-HNE和T-GSH/GSSG)水平;用蛋白免疫印迹法测定肝淋巴生成标志蛋白(PROX1和LYVE1),淋巴生成调节蛋白VEGF-C和淋巴连接蛋白VE-cadherin的蛋白质表达水平。结果PM2.5染毒显著增加了MAFLD组小鼠血清AST和ALT水平,显著降低了肝组织PROX1、LYVE1和VEGF-C蛋白表达水平,增加肝4-HNE水平和降低了肝T-GSH/GSSG水平(P<0.05)。然而,PM2.5染毒并没有显著影响C57BL/6J小鼠血清AST和ALT水平、肝组织中PROX1、LYVE1、VEGF-C和VE-cadherin的蛋白表达水平及肝的4-HNE和T-GSH/GSSG(P>0.05)。结论PM2.5染毒能显著加重MAFLD小鼠肝的氧化损伤,并且能通过降低肝VEGF-C减少肝淋巴生成。

山柰酚改善细颗粒物PM2.5诱导的老龄大鼠肺损伤的作用和机制研究

目的细颗粒物(PM2.5)被认为与多种呼吸系统问题有关,在老年人群中尤为显著。本研究旨在探索山柰酚是否可以治疗PM2.5诱导的老龄大鼠肺损伤,并探讨其潜在的作用机制。方法30只雄性Wistar大鼠(16个月龄)被随机分为5组:对照组、PM2.5暴露组和PM2.5暴露+山柰酚低剂量、中剂量和高剂量组。PM2.5暴露持续时间2周后,检测各组大鼠的肺功能、肺形态、炎症程度以及Toll样受体4(TLR4)/核因子-κB(NF-κB)信号通路相关蛋白的表达水平。结果与对照组相比,PM2.5暴露导致老龄大鼠发生显著的肺损伤,表现为明显的肺功能受损和组织病理学改变,支气管肺泡灌洗液(BALF)中的炎性因子TNF-α和IL-6浓度增加,血液中炎性细胞比例改变,肺组织中TLR4的表达和核转录因子-κB(NF-κB)磷酸化水平增加。山柰酚的治疗则呈剂量依赖性地改善了PM2.5所致肺功能损伤和组织病理学改变,抑制炎性因子分泌和炎症细胞比例失衡,抑制了TLR4/NF-κB信号通路的激活。结论山柰酚能够对PM2.5暴露引起的老龄大鼠肺损伤产生保护作用,抑制炎症反应和结构损伤,其作用机制可能与抑制TLR4/NF-κB信号通路的激活相关。

藤茶总黄酮对PM2.5所致大鼠肺损伤的作用研究

目的评价藤茶总黄酮对大气细颗粒物(PM2.5)所致大鼠肺损伤的作用。方法雄性Wistar大鼠35只随机分为5组:对照组,模型组,藤茶总黄酮(TF)高、中、低剂量组,每组7只。模型组、TF各组气管滴注PM2.5混悬液10 mg/kg,每周1次,共4次,对照组则以生理盐水进行气管滴注。滴注次日起,对照组、模型组以0.5%羧甲基纤维素钠灌胃,TF组以不同剂量(500、250、125 mg/kg)藤茶总黄酮灌胃,每周5次,共4周。收集大鼠肺组织、肺泡灌洗液(BALF),观察肺组织病理形态,检测肺组织中超氧化物歧化酶(SOD)、丙二醛(MDA)、谷胱甘肽过氧化物酶(GSH-Px),酶联免疫吸附试验(ELISA)检测BALF中肿瘤坏死因子-α(TNF-α)、白细胞介素-6(IL-6)、白细胞介素-1β(IL-1β)。结果与对照组相比,模型组大鼠肺组织损伤明显,SOD、GSH-Px活性显著降低,MDA含量、BALF中TNF-α、IL-6、IL-1β水平显著升高。在中高剂量TF干预下,PM2.5肺损伤模型大鼠的肺组织损伤减轻,SOD、GSH-Px活性显著增强,MDA含量、BALF中TNF-α、IL-6、IL-1β水平显著下降,差异有统计学意义。结论藤茶总黄酮对PM2.5所致大鼠肺损伤具有一定的保护作用,这一作用与减轻大鼠肺部的氧化应激和炎症反应有关。

Exposure to ambient air particulate matter and non-alcoholic fatty liver disease

The present study was designed to alert the public opinion and policy makers on the supposed enhancing effects of exposure to ambient air particulate matter with aerodynamic diameters < 2.5 mm (PM 2.5 ) on non-alcoholic fatty liver disease (NAFLD), the most common chronic liver disease in Western countries. For far too long literature data have been fixated on pulmonary diseases and/or cardiovascular disease, as consequence of particulate exposure, ignoring the link between the explosion of obesity with related syndromes such as NAFLD and air pollution, the worst characteristics of nowadays civilization. In order to delineate a clear picture of this major health problem, further studies should investigate whether and at what extent cigarette smoking and exposure to ambient air PM 2.5 impact the natural history of patients with obesity-related NAFLD,i.e. , development of non alcoholic steatohepatitis, disease characterized by a worse prognosis due its progression towards fibrosis and hepatocarcinoma.

Effects of Lianhua Qingwen on Pulmonary Oxidative Lesions Induced by Fine Particulates(PM2.5) in Rats

Objective To investigate the antagonistic effects of different doses of Lianhua Qingwen on pulmonary injury induced by fine particulates PM2.5 in rats. Methods Fine particulates suspended in the environment were collected. Forty-eight healthy adult wistar rats were randomly divided into 6 groups with 8 rats in each group. Four groups of rats were exposed to PM2.5 by intratracheally dripping suspensions of fine particulates PM2.5(7.5 mg/kg) as dust-exposed model rats. Among them 24 rats in three groups received Lianhua Qingwen treatment(crude drug) at a dose of 2 g/kg, 4 g/kg, 8 g/kg per day for 3 days before dust exposure and were defined as low-dose, middle-dose and high-dose Lianhua Qingwen treatment groups respectively. The other dust-exposed model rats without treatment were assigned as PM2.5 control group. The un-exposed rats were set as saline control group(1.5 ml/kg saline) and blank control group. All rats were killed after 24 hours of the exposure. Lung tissue, serum and bronchoalveolar lavage fluid(BALF) were collected. The levels of malonaldehyde(MDA), lactate dehydrogenase(LDH), and glutathione peroxidase(GSH-PX) in blood serum and BALF, and superoxide dismutase(SOD) in blood surum were measured using fluorescent quantitation PCR; Expression of NF-E2-related factor 2(NRF-2), heme oxygenase 1(HO-1) and quinone oxidoreductase 1(NQO1) in lung tissues were measured using Western blot. Pathological changes of lung tissues in each group were also examined. Results Pathology revealed thickened alveolar septum, congestion of capillary, interstitial edema and infiltration of lymphocyte and neutrophil surrounding bronchiole in the PM2.5 control group, which weresignificantly relieved in the Lianhua Qingwen treatment groups. Compared to the blank and saline control groups, the PM2.5 control group had significantly higher levels of LDH and MDA(p<0.01) and lower level of GSH-PS(p<0.01) in BALF, significantly higher levels of LDH and MDA(p<0.05) and lower level of GSH-PS(p<0.05) in rat serum. The levels of MDA in blood serum and BALF were significantly lower in each treatment group than that in PM2.5 control group(all P<0.05). In both middle-dose and high-dose treatment group the measurements of LDH in serum and BALF as well as GSH-PX in serum were significant difference from those of PM2.5 control group(all P<0.05). Expressions of NRF-2, HO-1 and NQO1 in lung tissues were significantly different among middle-dose and high-dose treatment group compared with those in PM2.5 control group(all P<0.05). Conclusion Fine particulates PM2.5 in environment may induce pulmonary oxidative lesions in rats. Middle-dose and high-dose Lianhua Qingwen has antagonist effece on the injuries induced by fine particulates.

Short-term exposure to fine particulate matter and hospital admission for stroke:a meta-analysis

Objective Air pollution is an important risk factor for cardiovascular diseases throughout the world.Fine particulate matter(PM)air pollution alone is responsible for over three million deaths each year.Large and growing literature has explored whether short-term exposure to fine particulate matter is associated with stroke,but results from prior studies have been inconsistent.To fill this gap,we assessed the evidence quantitatively from epidemiological time-series studies published worldwide and determined whether short-term exposure to fine particulate matter(<2.5μm or<10μm)diameter[PM2.5 and PM10]was associated with increased risk of hospital admission for stroke(including ischemic and hemorrhagic stroke).

Effect of Varying Temperature and Oxygen on Particulate Matter Formation in Oxy-Biomass Combustion

Offsetting particulate matter emissions has become a critical global aim as there are concerted efforts to deal with environmental and energy poverty challenges.This study consists of investigations of computing emissions of particulate matter from biomass fuels in various atmospheres and temperatures.The laboratory setup included a fixed bed electric reactor and a particulate matter(PM)measuring machine interfaced with the flue gas from the fixed bed reactor combustion chamber.The experiments were conducted at seven different temperatures(600℃-1200℃)and six incremental oxygen concentrations(21%-100%).Five biomass types were studied;A-cornstalk,B-wood,C-wheat straw,D-Rice husk,E-Peanut shell,each pulverized to a size of approximately 75 microns.The study shows that PM emitted during char combustion is consistently higher than that emitted during the de-volatilization.During de-volatilization,increase in temperature leads to linear decrease in PM emission between atmospheres of 21%O_(2)to 50%O_(2),thereafter,between 70%O_(2)to 100%O_(2);increase in temperature leads to a rise in PM emission.The average PM formation from all the five considered biomass is relatively comparable however,with differing atmospheres and temperatures,the fibrous and low-density biomass forms more PM.During char combustion,the study shows that at oxygen levels of 21%,70%,90%and 100%,increase in temperature leads to increased PM emission.The increase in oxygen concentration and temperature increases the rate of combustion hence diminishing the time of combustion.

A Study of the Correlation between the Concentration of Particulate Matter and Green Area Ratio Measured through a Portable Monitoring System: With Particular Focus on the Case of Dalseo-Gu, Daegu Metropolitan City

This study analyzed the relationship between the measured concentration of particulate matter (PM) and green area, which is an important spatial factor affecting urban PM concentration and even more carbon neutral in cities. In order to investigate the effects of green area, the green area ratio (GAR) is used and correlated with particulate matter. As a result of analyzing the correlation between GAR and PM concentration using the measured PM data, it was found that there was a positive correlation between the two variables. Hence, the higher the GAR, the lower the PM concentration. It can be said that the introduction of spatial elements with high GAR scores, such as parks and forests in cities, is effective in reducing PM concentration. In this study, a portable PM monitoring system using a vehicle for PM measurement was also established and operated. As a result, it was found that a PM monitoring system using a light-scattering sensor is an effective PM measurement method that can be used at the local government level. It was also found that a follow-up study is needed in the future to identify the PM mitigation functions of urban green areas according to the detailed characteristics of green areas as well as various environmental factors. This study can be used in air quality improvement activities and efforts as reference data by policy decision makers and in the field of environmental planning associated with the removal of airborne particulate matter pollution in urban areas.

Indoor and Outdoor Particulate Matter Exposure of Rural Interior Alaska Residents

To assess the exposure of residents in rural communities in the Yukon Flats to particulate matter of 2.5 μm or less in diameter (PM2.5), both indoor and outdoor concentration observations were carried out from March to September 2019 in Ft. Yukon, Alaska. Indoor concentrations were measured at 0.61 m (breathing level during sleeping) in homes and at 1.52 m heights (breathing level of standing adult) in homes and office/commercial buildings. Air quality was better at both heights in cabins than frame homes both during times with and without surface-based inversions. In frame houses, concentrations were higher at 0.61 m than 1.52 m, while the opposite is true typically for cabins. Differences between shoulder season and summer indoor concentrations in residences were related to changes in heating, subsistence lifestyle and mosquito repellents. In summer, office and commercial buildings, air quality decreased due to increased indoor emissions related to increased use of equipment and mosquito pics as well as more merchandise. During summer indoor concentrations reached unhealthy for sensitive groups to hazardous conditions for extended times that even exceeded the high outdoor concentrations. Due to nearby wildfires, July mean outdoor concentrations were 55.3 μg·m-3 which exceeds the 24-h US National Ambient Air Quality Standard of 35 μg·m-3. Indoor and outdoor concentrations correlated the strongest with each other for office/commercial buildings, followed by frame houses and cabins. Office/commercial buildings with temperature monitors had one to two orders of magnitude lower concentrations than those without.

Using a Parafoil Kite for Measurement of Variations in Particulate Matter—A Kite-Based Dust Profiling Approach

This paper reports on the use of a kite-based system for measuring low-altitude particulate matter (PM) concentrations over grassland in Inner Mongolia. The motivation came from PM-concentration measurements at heights below 3 m over non-erodible surfaces which showed constant concentrations and made flux calculations relatively uncertain. One aim was the quantification of wind-driven matter fluxes across ecosystem boundaries, where the relevant layer can be assumed at heights below 100 m. Compared to other measurement techniques (e.g. LIDAR, towers and airborne systems) kite-based systems represent an inexpensive, highly flexible research tool which is well-suited for application in remote sites. The basis of the introduced system is a 4 m2 Parafoil kite which has enough lifting capacity to carry equipment of about 6 kg at wind velocities between 3 ms-1 to nearly 20 ms-1. A self-adjusting platform was constructed to balance moves and to carry a portable Environmental Dust Monitor (EDM), anemometer and a GPS receiver. So, all parameters necessary for a vertical profile of dust fluxes could be measured. In the first flights the applied kite-based dust profiling system (KIDS) was examined according to general technical application problems. Firstly, the influence of diverse surface characteristics, the flying condition and height-stability was tested. The result suggests that surface characteristics in general have a higher influence than the optimal wind velocity, which ranged from 9 ms-1 to 17 ms-1. Secondly, uncertainties in the measured data were quantified and assessed. The uncertainties in wind velocity measurements due to motion in horizontal and vertical direction were not higher than 0.45% - 0.65% and 1.8% - 2.2% during the kite ascent. The outcome of the study illustrates the suitable application of KIDS for low-altitude measurements in remote sites.

PM2.5与妊娠不良结局的相关性研究进展

大气污染对人体的不良健康影响已受到国内外学者的广泛关注,其中大气细颗粒物(PM2.5)不但会对机体的呼吸、心血管、免疫等系统带来损害,甚至还会威胁下一代健康。妊娠期女性完全暴露于一定浓度的PM2.5可能会引起早期妊娠丢失、死胎死产、低出生体重儿、早产、出生缺陷等不良妊娠结局,乃至会完全破坏子代的代谢等,导致其出生后会个别慢性疾病的易感率大大提升。在本研究中,笔者对PM2.5致妊娠不良结局的流行病学、动物学研究进度实施概述、分析等,以期为今后的研究提供参考。

哈尔滨市大气PM_(2.5)中五种金属成分复合暴露对人群死亡风险的影响

目的定量评估哈尔滨市大气PM_(2.5)中金属成分复合暴露对人群死亡的暴露-反应关系及联合效应大小。方法基于监测系统收集哈尔滨市2013—2018年每日死亡数据、每日气象和大气污染物数据。采集大气细颗粒物(PM_(2.5))并进行金属成分浓度测定,基于随机森林模型预测大气PM_(2.5)中每日金属成分浓度。运用分位数g计算回归(quantile g-computation,qgcomp)估计大气PM_(2.5)中金属成分复合暴露对非意外、心血管系统和呼吸系统疾病死亡的联合效应,并探索敏感暴露人群,最后采用加权分位数和回归(weighted quantile sum regression,WQS)进行敏感性分析。结果2013—2018年期间,哈尔滨市非意外、心血管系统和呼吸系统疾病日均死亡人数的中位数(M)分别为75、42和7例。大气PM_(2.5)多种金属成分复合暴露每增加一个四分位数,非意外死亡的相对风险(relative risk,RR)为1.026(95%CI:1.010~1.043);心血管系统疾病死亡风险的RR值为1.038(95%CI:1.016~1.060)。分层分析结果表明男性和≥60岁人群为大气PM_(2.5)金属复合暴露的敏感人群。敏感性分析进一步证实上述研究结果较稳健,且金属As对人群死亡贡献的权重最大。结论大气PM_(2.5)中金属成分复合暴露可增加人群非意外死亡和心血管系统疾病死亡的发生风险,且男性和≥60岁人群是金属复合暴露的敏感人群。

北京地区紫外辐射长期变化特征分析研究

本文利用2005~2020年北京地区观测得到的辐射资料,揭示近十多年来北京地区紫外辐射的变化规律,同时对影响紫外辐射长期变化的主要因子进行了分析。结果表明,紫外辐射呈现出明显的日、季节变化特征。日变化呈现出单峰的变化规律,在正午时出现一天中的极大值,而早晚则是低值时段,极大值和极小值分别出现在中午12时(北京时,下同;16.26 W m^(−2))和上午08时(5.64 W m^(−2))。紫外辐射从春季开始逐渐增强,到夏季出现一年中的极大值,随后开始下降,直到冬季出现一年中的极小值,月均极大值和极小值分别出现在6月(12.17 W m^(−2))和12月(5.4 W m^(−2))。紫外辐射年均值为9.74 W m^(−2)。紫外辐射与晴空指数呈现正相关,与气溶胶光学厚度和大气细颗粒物PM_(2.5)呈现负相关。

2020—2022年海口市城区大气PM_(2.5)中重(类)金属组成及来源解析

目的探析海口市主城区大气PM_(2.5)中重(类)金属污染的组成和主要来源。方法于2020—2022年对海口市主城区进行逐月定期(10—16日)采集大气PM_(2.5)样品,每日持续采样时间不少于22 h;利用电感耦合等离子体质谱法(ICP-MS)测量PM_(2.5)样品中25种重(类)金属成分;对PM_(2.5)中检出率较高的16种重(类)金属成分采用正定矩阵因子分解模型(PMF)解析主要污染来源。结果2020—2022年海口市主城区大气PM_(2.5)质量浓度范围4.00~64.00μg/m^(3),均数(x±s)为(20.48±12.88)μg/m^(3)、中位数(M)17.00μg/m^(3)及四分位数间距(IQR)14.25μg/m^(3),年度间PM_(2.5)24小时平均浓度差异不具有统计学意义(χ^(2)=1.24,P>0.05);不同季节PM_(2.5)24小时平均浓度差异具有统计学意义(χ^(2)=44.86,P<0.01),PM_(2.5)24小时平均浓度(均数)高低顺序为冬季>秋季>春季>夏季;16种重(类)金属的质量浓度范围为0.01~1008.00 ng/m^(3),质量浓度M值由高到低依次为Fe>Al>Zn>Mn>Pb>Ba>Cu>Sr>Ni>Se>V>As>Sn>Cr>Cd>Li。PMF模型解析结果表明,PM_(2.5)中16种重(类)金属污染主要贡献来源以道路及土壤尘源(49.82%)和交通尾气源(36.96%)为主,次之贡献源有混合燃烧源(9.61%)、建材施工尘源(2.51%)和船舶燃油源(1.10%)。结论2020—2022年海口市大气PM_(2.5)质量浓度均未超过我国《环境空气质量标准》(GB 3095-2012)24小时平均浓度二级限值(75μg/m^(3))水平,PM_(2.5)中重(类)金属构成主要以Fe、Al、Zn、Mn和Pb元素为主,其主要贡献源是道路及土壤尘源和交通尾气源。

2022年南京市大气PM_(2.5)中多环芳烃污染特征及健康风险

目的了解南京市大气细颗粒物(PM_(2.5))中多环芳烃(polycyclic aromatic hydrocarbons,PAHs)污染特征,评估其健康风险。方法于2022年每月10—16日分别在江北新区和江宁区2个监测点开展PM_(2.5)和PAHs采样,分别采用称重法和高效液相色谱法测定PM_(2.5)和PAHs含量,利用健康风险评价模型评价PAHs的致癌风险。结果不同季节PM_(2.5)、PAHs和B[a]P的浓度存在差异(P<0.01),其中PM_(2.5)、PAHs浓度均是冬、春季高于夏、秋季,B[a]P浓度春季高于夏、秋季。两个监测点PAHs、B[a]P年均浓度、春季、夏季浓度的比较,差异均具有统计学意义(P<0.05),且江北新区均高于江宁区。两个监测点含量最高的多环芳烃是5环、其次是4环和6环。两个监测点3环、4环、5环、6环PAHs年均浓度均不同(P均<0.05),江北新区高于江宁区。PAHs年浓度中位数值对两个监测点人群的终生超额致癌风险均大于1.0×10^(-6)。PAHs年浓度95分位数对人群的年龄段超额致癌风险除江宁区0~2岁年龄段人群外,对其他年龄段人群的超额致癌风险均大于1×10^(-6)。结论南京市两个监测点大气PM_(2.5)中PAHs分布存在季节和地区差异,具有潜在的超额致癌风险。