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.

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.

Feature Analysis of the Atmospheric Particulate Pollutants (PM_(10) and PM_(2.5)) in Wenzhou City

[ Objective] The research aimed to analyze characteristics of the atmospheric particulate pollutants （ PMlo and PM2.s） in Wenzhou City. [Method] We analyzed interannual change rule of the dust haze in Wenzhou during 1978 -2008. Moreover, we respectively set monitoring points in urban district, industrial park and beauty spot of Wenzhou in summer and winter of 2010. Element, ion and polycyclic aromatic hydrocarbon com- positions and morphology of the particulate matter were analyzed. [ Result] Dust haze in Wenzhou City mainly appeared in winter and spring, which was related to local meteorological condition. In summer and winter, both PMlo and PM2.s concentrations presented the characteristic of industrial park 〉 commercial area 〉 beauty spot. Chain-like particle aggregates and ultrafine particles were main composition of the atmospheric particulate matter in Wenzhou. Contribution rate of the spherical particle amount was smaller than metropolis, which was related to local industry and traffic. Fe element had the most content in particulate matter. Mass concentration was mainly composed of 6 elements, such as Na, Si, S, K, Ca and Fe. Total concentration of the six elements occupied 70% -80% of the 16 elements. SO^- and NH4＊ in particulate matter were higher. They were mainly from human activity. Main compositions of the polycyclic aromatic hydrocarbon were naphthalene, anthracene, benzo （b） fluoranthene, indeno （1,2, 3-cd） pyrene and benzo （g, h, i） perylene, which was related to abrupt increase of the motor vehicle. [ Condusion] The research provided scientific basis and technology support for controlling atmospheric particulate matter pollution in Wenzhou City by government and related department.

Fine Particulate Pollution Characteristics in Jinan City

The characteristics of fine particulate pollution(PM10 and PM2.5) were measured at urban and suburban sites in Jinan during the 2008-2009 heating and non-heating seasons.The results showed that PM10 and PM2.5 pollution was quite serious,and PM mass concentration was higher during the heating season than the non-heating season.PM was the highest in the chemical factory and lowest in the development zone.The mass concentrations of PM10 and PM2.5 were linearly related,and the mass concentration ratio of PM2.5/PM10 was up to 0.59 in urban areas.PM pollution in Jinan was related to local meteorological factors:PM2.5 mass concentration and humidity were positively correlated,and PM2.5 mass concentration was negatively correlated with both click on the temperature and wind speed,although wind speed varied more.

Antagonistic Effects of N-acetylcysteine on Mitogen-activated Protein Kinase Pathway Activation, Oxidative Stress and Inflammatory Responses in Rats with PM2.5 Induced Lung Injuries

Objective To evaluate the antagonistic effects of N-acetylcysteine(NAC)on mitogen-activated protein kinases(MAPK)pathway activation,oxidative stress and inflammatory responses in rats with lung injury induced by fine particulate matter(PM2.5).Methods Forty eight male Wistar rats were randomly divided into six groups:blank control group(C1),water drip control group(C2),PM2.5 exposed group(P),low-dose NAC treated and PM2.5 exposed group(L),middle-dose NAC treated and PM2.5 exposed group(M),and high-dose NAC treated and PM2.5 exposed group(H).PM2.5 suspension(7.5 mg/kg)was administered tracheally once a week for four times.NAC of 125 mg/kg,250 mg/kg and 500 mg/kg was delivered intragastrically to L,M and H group respectively by gavage(10 ml/kg)for six days before PM2.5 exposure.The histopathological changes and human mucin 5 subtype AC(MUC5AC)content in lung tissue of rats were evaluated.We investigated IL-6 in serum and bronchoalveolar lavage fluid(BALF)by Enzyme-linked immunosorbent assay(ELISA),MUC5AC in lung tissue homogenate by ELISA,glutathione peroxidase(GSH-PX)in serum and BALF by spectrophotometry,and the expression of p-ERK1/2,p-JNK1/2 and p-p38 proteins by Western blot.All the measurements were analyzed and compared statistically.Results Lung tissue of rats exposed to PM2.5 showed histological destruction and increased mucus secretion of bronchial epithelial cells.Rats receiving NAC treatment showed less histological destruction and mucus secretion.Of P,L,M and H group,MUC5AC in lung tissue,IL-6 in serum and BALF were higher than controls(C1 and C2)(all P<0.05),with the highest levels found in the P group and a decreasing trend with increase of NAC dose.The activity of GSH-PX in serum and BALF of PM2.5 exposed rats(P,L,M and H)was lower than that of controls(all P<0.05),with higher activities found in NAC treated rats(L,M,and H),and an increasing trend with increase of NAC dose.The expressions of p-ERK1/2,p-JNK1/2 and p-p38 proteins in PM2.5 exposed lung tissue(P,L,M and H)was higher than controls(all P<0.05),with decreased levels and dose dependent downregulation found in NAC treated rats.Conclusion NAC can antagonize major MAPK pathway activation,lung oxidative stress and inflammatory injury induced by PM2.5 in rats.

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。

临沂市冬季环境空气PM2.5中水溶性离子污染特征及来源分析

为探究临沂市冬季环境空气PM2.5中水溶性离子污染特征及来源,于2016年12月11日—2017年1月9日在临沂大学、兰山区政府、高新区翠湖嘉园、汤庄办事处、河东区政府、临沂开发区6个采样点开展样品采集.结果表明:①采样期间全市ρ(PM2.5)日均值的平均值为144.86 μg/m^3,ρ(PM2.5)日均值在2016年12月20日和2017年1月4日出现峰值,分别为304.46 和341.65 μg/m^3.②水溶性离子日均质量浓度大小顺序依次为ρ(NO3^-)>ρ(SO4^2-)>ρ(NH4^+)>ρ(Cl^-)>ρ(K^+)>ρ(Ca^2+)>ρ(Na^+)>ρ(F^-)>ρ(Mg^2+)>ρ(NO^2-),其中,在PM2.5中w(NO3^-)、w(SO4^2-)、w(NH4^+)分别为22.33%、16.57%、13.62%,说明NO3^-、SO4^2-和NH4^+是临沂市PM2.5的主要组成部分.③临沂市污染天和非污染天ρ(PM2.5)日均值分别为164.00和56.86 μg/m^3.随污染水平增加,PM2.5中w(NO3^-)明显增高,w(SO4^2-)和w(NH4^+)基本不变,说明w(NO3^-)的增加导致ρ(PM2.5)的升高.污染天和非污染天的NOR (氮氧化率)分别为0.28和 0.11,SOR (硫氧化率)分别为0.34和0.28,说明污染越重,NOR和SOR越高,并且NO x 的气-粒转化速率较SO 2慢.污染天ρ(Cl^-)和ρ(K^+)分别为7.22和1.77 μg/m^3,分别是非污染天的2.5和3.0倍.④采样期间非污染天和污染天的N/S 〔ρ(NO3^-)/ρ(SO4^2-)〕分别为0.85和1.39,说明非污染天时固定源对PM2.5的贡献相对较大,而污染天时移动源对PM2.5的贡献相对较大.⑤通过PMF模型法解析出3个因子.因子1对PM2.5中水溶性离子的贡献率为56.13%,代表二次源和生物质燃烧源;因子2的贡献率为25.22%,代表工业源和垃圾焚烧源;因子3的贡献率为18.65%,代表扬尘源.研究显示,临沂市冬季PM2.5污染严重,水溶性离子来源复杂,应采取多源控制的污染防治对策.

Predictive Meteorological Factors for Elevated PM2.5 Levels at an Air Monitoring Station Near a Petrochemical Complex in Yunlin County, Taiwan

Since 1991, air pollution has gained special attention in Taiwan after a petrochemical complex was constructed in Mailiao Township, Yunlin County. We explored the association between the magnitude of PM2.5 and meteorological factors during 2012-2016. Our findings revealed that 1) mean PM2.5 levels gradually decreased from 30.70 μg/m3 in 2013 to 25.36 μg/m3 in 2016;2) wind speed is the main determinant of air quality—air quality significantly improved when it was faster than 4 m/sec;and 3) wind direction is another determinant of air quality—when the wind direction was southerly, air quality improved. Elevated PM2.5 levels were defined as those hourly levels higher than the third quartile (36 μg/m3). The significantly negative predictive factors for elevated PM2.5 levels were the summer or autumn seasons, rainfall, increased wind speed, and wind direction from 150&#176 to 230&#176 from the north. The significantly positive predictive factors for elevated PM2.5 levels were working hours from 6 a.m. to 2 p.m., a temperature between 11&#176C and 25&#176C, relative humidity between 40% and 68%, and wind direction (e.g., northerly wind, northeasterly wind, and easterly wind). The predictive formula is attached in the Appendix. Therefore, people should protect themselves on these high-risk days.

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.

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。

基于机器学习的郑州市大气PM_(2.5)与O_(3)浓度预测方法及气象因子的影响分析

近年来,我国面临着细颗粒物(PM_(2.5))污染形势依然严峻以及臭氧(O_(3))污染日益凸显的双重压力.为进一步准确预测郑州市大气PM_(2.5)与O_(3)浓度并探明气象因子的影响,本研究使用2018−2022年郑州市大气污染物和气象因子逐时数据,结合统计学单因素分析和机器学习LightGBM模型多因素分析,建立了一种基于长时间序列数据的PM_(2.5)与O_(3)浓度预测及气象因子影响分析的综合分析方法.结果表明:①训练后的LightGBM模型能够较好地预测PM_(2.5)污染,准确率达80.8%;对O_(3)污染预测的准确率为52.5%.②郑州市大气PM_(2.5)浓度与气压呈正相关,与比湿和环境温度均呈负相关;大气O_(3)8 h滑动平均浓度(O_(3)-8 h浓度)与比湿和太阳辐射均呈正相关,与气压呈负相关.③有利的气象条件可能是2021年PM_(2.5)年均浓度得到显著改善的重要因素;同时,不利的气象条件也促使2021年和2022年6月O_(3)月评价值(O_(3)日最大8 h滑动平均90百分位浓度)有所上升.研究显示,这种基于长时间序列的综合分析方法适用于大气PM_(2.5)与O_(3)浓度的气象因子影响分析,也能有效预测PM_(2.5)与O_(3)的浓度.

2016—2022年珠三角地区PM_(2.5)中多环芳烃污染特征及健康风险

目的评价多环芳烃暴露的人群健康风险,了解珠三角地区大气PM_(2.5)及其中16种多环芳烃的污染特征和来源。方法2016—2022年在广东省珠三角地区的广州、深圳、佛山及珠海市选10个区设置10个监测点,每月10—16日采集环境空气样品,测定PM_(2.5)及其中16种多环芳烃含量,分析多环芳烃污染来源,使用BaP毒性当量法评价多环芳烃呼吸暴露途径的人群健康风险。结果2016—2022年珠三角地区PM_(2.5)逐年平均浓度(x±s)分别为(57.45±29.66)、(51.26±35.69)、(43.86±33.17)、(40.53±24.70)、(29.26±34.27)、(31.57±24.91)、(30.17±21.06)μg/m^(3),呈下降趋势(Z=-29.83,P<0.01),PM_(2.5)中多环芳烃平均浓度(x±s)分别为(6.23±6.29)、(5.17±6.95)、(4.00±4.46)、(3.34±3.93)、(2.52±2.92)、(3.05±4.30)、(2.65±2.60)ng/m^(3),浓度虽然降低近60%,但下降趋势无统计学意义,多环芳烃16种成分除萘(NAP)外均呈下降趋势(P<0.05),2018—2022年PM_(2.5)中多环芳烃致癌效应健康风险CR值M(P_(25),P_(75))为5.35×10^(-7)(2.54×10^(-7),1.21×10^(-6)),自第69百分位数开始大于1×10^(-6),第99百分位数为9.19×10^(-6),均小于1×10^(-4)。结论珠三角地区四城市大气PM_(2.5)污染整体呈不断改善趋势,四城市中临海的深圳和珠海市优于佛山和广州市,PM_(2.5)与多环芳烃成分含量呈显著正相关,逐月变化趋势基本一致。多环芳烃污染主要是本地源排放所致,存在石化燃料燃烧、机动车尾气排放、石油挥发和有机物质燃烧等多重来源,不同城市多环芳烃污染构成和来源并不完全一致,且高温燃煤对多环芳烃浓度变化有重要影响。珠三角地区大气PM_(2.5)中多环芳烃具有潜在致癌风险,宜引起关注。

妊娠期PM_(2.5)暴露与足月低体重儿的关联分析

目的探讨孕期各阶段PM_(2.5)暴露与足月低体重儿发生风险的关系。方法收集2015年9月1日至2017年12月31日在河北省22个危重孕产妇监测点分娩的118783名孕产妇住院资料,并收集其孕期各阶段的空气质量监测数据;根据足月新生儿是否低体重儿,将其分为足月低体重儿组和足月非低体重儿组,比较两组的孕期PM_(2.5)暴露情况,采用logistic回归模型分析其对足月低体重儿患病的影响。结果足月低体重儿组孕期各阶段PM_(2.5)暴露水平明显高于足月非低体重儿组(P<0.05);妊娠期暴露于PM_(2.5)会增加足月低体重儿的发生风险;全孕期、孕早期、孕中期、孕晚期PM_(2.5)暴露浓度每增加10μg/m3,足月低体重儿的发生风险分别增加4.9%、1.6%、1.7%、1.5%;高龄妊娠、低龄妊娠、产检次数少、初产、多产次(产次≥2)、多胎妊娠、胎儿女性、孕妇患妊娠高血压疾病、前置胎盘、胎盘早剥、心脏病均为足月低体重儿的独立危险因素(P<0.05)。结论妊娠期高浓度PM_(2.5)暴露会显著增加足月低体重儿的发生风险,应注意做好孕期防护。

水泥窑PM_(2.5)排放特性及其PAHs风险分析

采用荷电低压颗粒物撞击器(ELPI)、便携式PM2.5采样器和稀释系统,对国内3家新型干法水泥生产厂(5条生产线)的水泥窑(包括窑头和窑尾)进行现场采样,分析水泥窑排放PM2.5的质量浓度、粒数浓度及其中的多环芳烃(PAHs)浓度,对呼吸致癌风险进行评价.结果表明:从粒数浓度分析,PM2.5中70%以上为PM0.33,这部分颗粒物主要是由气化凝结形成的.各采样点排放的PAHs主要以二环和三环的低环PAHs为主.第3个水泥厂窑头排放的PAHs含量最高,而且苯并[a]芘(BaP)超过国家所规定的8ng/m3标准限值,同时其呼吸致癌风险水平为4.46×10-4,高于可接受致癌风险水平的上限,需要有效处理.

基于X射线荧光光谱的大气重金属在线分析方法的评估及应用

实验自行搭建了一套基于X射线荧光光谱(XRF)的大气重金属分析仪,建立了大气颗粒物中多种重金属同时在线分析的方法,并通过测定标准膜片评估了方法的准确性、灵敏度、重复性以及检出限等。通过与国家标准方法采用的电感耦合等离子体质谱法(ICP-MS)的实验结果对比,结果表明方法能够较为准确的测定大气颗粒物中多种重金属的含量,相对误差在15%以内。采用实验仪器在线测定了一段时期室内外大气颗粒物中重金属的含量,并结合发布的空气质量指数(AQI)进行了初步分析,结果表明重金属与细颗粒物(PM2.5)含量具有一定正相关性;通过在广东某大气超级监测站一个月内的监测数据,证明了仪器实际应用的可靠性。通过上述方法的开发、参数评估以及简单应用,结合多种数据的交叉分析,表明实验方法能够满足日常的重金属监测需要。

南充市大气细颗粒物PM_(2.5)的监测及污染控制研究

针对南充市大气细颗粒物PM_(2.5)的监测及其污染控制探讨问题。首先对PM_(2.5)的监测进行了介绍,在这里介绍了南充市污染气象的数据、南充市高坪区环境空气污染气象的数据和南充市三区环境空气的状况,然后探讨了南充市PM_(2.5)监测站网的建设,在这里同时探讨了国外PM_(2.5)监测站网概况和中国对PM_(2.5)监测站网的建设,最后对PM_(2.5)对环境产生的影响进行了总结,对南充市PM_(2.5)对大气层及气候环境产生的影响和PM_(2.5)进行了探讨。

2016年北京市某城区采暖季PM_(2.5)中PAHs的污染特征及来源分析

目的分析2016年北京市某城区采暖季重污染与非重污天气过程PM_(2.5)中PAHs的污染特征,并对PAHs的污染来源进行初步识别。方法2016年12月30日—2017年2月9日连续采集42 d PM_(2.5)样品,采用高效液相色谱法测定PAHs水平,分析比较重污染与非重污染天气过程PAHs的污染特征,采用特征比值法对PAHs的污染来源进行初步识别。结果采样期间PM_(2.5)及其PAHs质量浓度M(P_(25),P_(75))为78.23(50.05,218.93)μg/m^(3)和58.06(25.23,112.13)ng/m^(3);重污染天气过程的PM_(2.5)及PAHs质量浓度中位数分别是非重污染天气过程的3.94倍和2.89倍;无论是重污染还是非重污染天气过程,单体PAHs中占比最高的均为荧蒽、苯并b荧蒽和芘,累积占比达50%,其次是Ba P,占比为10%;4环PAHs占比最高(50.5%±9.2%),其次是5环PAHs(34.5%±7.2%),6环PAHs(15.0%±3.7%)最低。重污染与非重污染天气过程单体和环数占比分布变化不大。4环PAHs/(5环PAHs+6环PAHs)、Ba P/Bghi P、Ind/(Ind+Bghi P)、Fl T/(Fl T+Pyr)和Ba A/(Ba A+Chr)的均值分别为1.08、1.56、0.53、0.58和0.49,提示PAHs污染主要来自本地污染源,煤/生物质燃烧源和交通源为主要污染来源。结论2016年北京市某城区采暖季PAHs污染水平仍处于较高水平,燃煤和机动车尾气是其主要来源,建议周边居民出行应做好个人健康防护。

石家庄市大气PM_(2.5)中PAHs污染特征及来源分析

在石家庄市城区内采集2019年全年大气细颗粒物(PM_(2.5))样品,采用气相色谱—质谱法测定其中多环芳烃(PAHs)浓度,分析了石家庄市PM_(2.5)中PAHs的不同时期污染水平、组成特征及主要来源。结果表明,石家庄市PM_(2.5)中总多环芳烃(ΣPAHs)质量浓度年均值为74.12 ng/m^(3),季节规律为春季(19.66 ng/m^(3))<夏季(53.52 ng/m^(3))<秋季(61.03 ng/m^(3))<冬季(145.16 ng/m^(3)),月平均浓度为16.51~230.40 ng/m^(3);单体BkF和Chry的月、季、年均浓度均在ΣPAHs中占比最高;环数分布特征为4环和5环的PAHs含量明显高于3环和6环的;采用特征化合物比值法分析,石家庄市PM_(2.5)中PAHs污染主要来自于液体石化燃料、煤炭和生物质燃烧源。

南宁市大气颗粒物PM_(l0)、PM_(2.5)污染水平

为了初步调查南宁市大气中颗粒物PMl0、PM2.5的污染水平 ,于2002年春、夏、秋、冬4季在南宁市的5个典型城市功能区 ,采集了85个样品.结果表明 ,南宁市PMl0、PM2.5 的污染很严重 ,超标率为82.5 %、92.5% ,而且对人体健康危害更大的PM2.5 占PM10 的大部分 ,约为63.5 % ,且重污染区PM2.5 浓度超过轻污染区近一倍 ,应引起公众和相关职能部门的高度重视.

细颗粒物对Apo E基因敲除小鼠动脉粥样硬化斑块及其内部巨噬细胞表型的影响

目的探讨细颗粒物(PM 2.5)对Apo E基因敲除(Apo E-/-)小鼠动脉粥样硬化(AS)斑块及其内部巨噬细胞表型的影响。方法将32只8周龄雄性Apo E-/-小鼠(AS模型小鼠)随机分为两组,均给予高脂饲料喂养8周,同时对照组、PM 2.5组分别气管滴注生理盐水、PM 2.5生理盐水混悬液。8周后,采用电感耦合等离子体质谱法测定小鼠全血重金属含量,Movat染色法评估主动脉根部斑块面积,天狼星红染色检测斑块内胶原含量,免疫组化染色分别检测斑块内巨噬细胞(MAC-2阳性区域)和平滑肌细胞(β-actin阳性区域)数量,实时荧光定量PCR法检测降主动脉斑块中M1型[诱导型一氧化氮合酶(iNOS)、白细胞介素12(IL-12)]和M2型[精氨酸酶1(Arg-1)、CD206]巨噬细胞标志性因子基因。结果与对照组比较,PM 2.5组全血中重金属成分中铝、钒、铁含量升高,斑块面积增大,斑块中巨噬细胞数量增加、胶原含量降低,斑块内M1型巨噬细胞标志性因子iNOS、IL-12 mRNA表达增加而M2型巨噬细胞标志性因子CD206、Arg-1 mRNA表达下降(P均<0.05)。结论PM 2.5暴露促进了Apo E-/-小鼠AS的进展,其原因可能与动脉粥样斑块内巨噬细胞向M1表型倾斜有关。