Oxidative damage of chronic PM2.5 exposure to rat lung tissue

Objective:To investigate the oxidative damage caused by chronic exposure to PM2.5 in rat lung tissues according to the PM2.5 concentration in the atmospheric environment.Methods:Forty healthy SD rats were randomly divided into 4 groups,the control group and the 5 mg/kg,10 mg/kg,20 mg/kg PM2.5 exposure groups.The rats in each group were administered by intratracheal instillation with 1ml/kg,2 times per week.After 8 weeks of exposure,the changes of lung histopathology,superoxide dismutase(SOD),malondialdehyde(MDA),catalase(CAT)and reduced glutathione/oxidized glutathione(GSH/GSSG)were detected.Results:Compared with the control group,the histopathological changes in the lung tissue of the three dose groups exposed to PM2.5 were significant.Masson staining showed obvious collagen fibrosis.The activities of SOD and CAT in the lung tissue of the exposed group were decreased,and the contents of MDA were increased with statistically significant(P<0.05),showing that the difference was the most obvious in the middle-dose group.The GSH/GSSG ratio in the lung tissue decreased,indicating that the degree of oxidative damage was aggravated.Conclusion:Chronic exposure to PM2.5 could induce oxidative stress in the lung tissue of rats and caused different degrees of oxidative damage.

上海市A城区大气PM_(10)、PM_(2.5)污染与居民日死亡数的相关分析

目的 探讨大气颗粒物污染对人群健康的影响。方法 采用Poisson广义相加模型对上海市A城区大气PM1 0 、PM2 5的日平均污染浓度与居民日死亡数进行相关回归分析 ,并控制了时间长期趋势、气象、季节、一周日效应混杂因素的影响。结果 当大气PM1 0 、PM2 5浓度上升 10 μg m3时 ,总死亡数分别上升 0 5 3%(0 2 2 %～ 0 85 % )、0 85 % (0 32 %～ 1 39% )。结论 大气粗细颗粒物污染具有潜在的急性人群健康危害。

室内PM_(2.5)暴露水平影响研究

近年来,雾霾天气频繁发生,大气污染已引起世界范围的殷切关注;并且成为世界共同研究的课题,其中细颗粒物污染已成为首要问题。而伴随着生活方式的转变,人们越来越注重室内空气品质,因此,室内PM_(2.5)污染已成为亟需解决的问题。通过分析室内PM_(2.5)污染来源以及对人体健康的影响,进行了关于室内PM_(2.5)暴露水平影响的实验研究。结果表明,吸烟是室内PM_(2.5)的主要来源;吸烟时会使室内PM_(2.5)暴露水平显著升高;烹饪会使室内PM_(2.5)暴露水平严重超标;人员活动产生的细颗粒物强度取决于室内的人数、活动类型、活动强度等;室内PM_(2.5)暴露水平受室外影响较大,呈现明显的正相关性。

Characterizing PM_2.5Pollution of a Subtropical Metropolitan Area in China

The chemical and physical characteristics of PM2.5, especially their temporal and geographical variations, have been explored in metropolitan Hangzhou area (China) by a field campaign from September 2010 to July 2011. Annual average concentrations of PM2.5 and PM10 during non-raining days were 106 - 131 μg.m-3 and 127 - 158 μg.m-3, respectively, at three stations in urban breathing zones, while corresponding concentrations of PM2.5 and PM10 at an urban background station (16 mabove ground level in a park) were 78 and 104 μg.m-3, respectively. For comparison, the annual average PM10 concentration at a suburban station (5 mAGL) was 93 μg.m-3. Detailed chemical analyses were also conducted for all samples collected during the campaign. We found that toxic metals (Cd, As, Pb, Zn, Mo, Cu, Hg) were highly enriched in the breathing zones due to anthropogenic activities, while soluble ions (, , ) and total carbon accounted for majority of PM2.5 mass. Unlike most areas in China where sulfate was several times of nitrate in fine PM, nitrate was as important as sulfate and highly correlated with ammonium during the campaign. Thus, a historical shift from sulfate-dominant fine PM to nitrate-dominant fine PM was documented.

南充交警大气PM2.5个体暴露水平及健康风险评价

为探讨交警工作环境大气PM2.5个体暴露水平,现场监测交警大气PM2.5个体暴露浓度,同时采集个体暴露大气PM2.5样品,分析样品的化学成分并对部分元素进行健康风险评价。结果表明,交警大气PM2.5个体暴露浓度为74.4μg/m^3,明显高于大气环境浓度42.2μg/m^3;交警PM2.5个体暴露浓度与风速、湿度负相关,与温度存在一定程度上的正相关,降雨能降低PM2.5个体暴露浓度。应用健康风险评价模型发现Mn对交警存在非致癌风险,风险指数为2.48;Cr对交警存在致癌风险,风险指数为1.58×10^-3,应予以重视。

不同出行方式大气PM2.5个体暴露分析

于2017年7月在南充市城区固定线路,分别用粉尘测定仪和激光粒子计数器连续6d对步行、出租车、公交车、摩托车、私家车、自行车6种出行方式大气PM2.5个体暴露质量浓度、数浓度进行监测,分析不同出行方式大气PM2.5个体暴露质量浓度和数浓度。结果表明,不同出行方式质量浓度最高和最低分别为自行车(68.0±32.2)μg/m^3和出租车(35.6±21.5)μg/m^3;数浓度最高和最低分别为步行(1.93×10^8)N/m3和私家车(2.49×10^4)N/m^3。质量浓度和数浓度的暴露量最高分别为自行车(76.6±3.8)μg和自行车(2.25×10^8)N;两种浓度下出租车和私家车比较结果相差不大,而其他四种出行方式呈现完全不同的结果。

HMGA2基因缺失对PM2.5暴露致大鼠肺损伤和心功能不全的影响

目的探讨HMGA2基因缺失对PM2.5暴露致大鼠肺损伤和心功能不全的影响。方法将野生型(WT)大鼠按体重用随机数字表法分为对照组和PM2.5组,每组5只大鼠;将HMGA2^(-/-)大鼠按体重用随机数字表法分为HMGA2^(-/-)组和HMGA2^(-/-)+PM2.5组,每组5只大鼠。对照组和HMGA2^(-/-)组大鼠每天气管滴注0.3 ml 0.9%氯化钠溶液,PM2.5组和HMGA2^(-/-)+PM2.5组每天气管滴注0.3 ml PM2.5混悬液,连续4周后对大鼠的心功能[左心室射血分数(LVEF)、左心室缩短分数(LVFS)]和肺功能[肺活量(FVC)、最大通气量(MVV)]进行评价,检测大鼠血清中白介素-6(IL-6)、肿瘤坏死因子α(TNF-α)、3-硝基酪氨酸(3-NT)和4-羟基壬烯醛(4-HNE)水平,同时检测肺和心脏组织中高迁移率族蛋白A2(HMGA2)、核转录因子-κB(NF-κB)和过氧化物还原判酶5(PRDX5)蛋白水平。结果HMGA2^(-/-)组和HMGA2^(-/-)+PM2.5组大鼠肺和心脏组织中HMGA2无表达;与对照组比较,PM2.5组肺和心脏组织中HMGA2表达降低,差异有统计学意义(P<0.05);与对照组比较,HMGA2^(-/-)组各指标差异无统计学意义(P>0.05);与对照组比较,PM2.5组和HMGA2^(-/-)+PM2.5组大鼠FVC、MVV、LVEF和LVFS降低,IL-6、TNF-α、3-NT和4-HNE增加,肺和心脏组织中NF-κB和PRDX5降低(P<0.05);与PM2.5组比较,HMGA2^(-/-)+PM2.5组大鼠FVC、MVV、LVEF和LVFS降低,IL-6、TNF-α、3-NT和4-HNE增加,肺和心脏组织中NF-κB增加、PRDX5降低(P<0.05)。结论HMGA2基因敲除能加重PM2.5暴露致大鼠肺损伤和心功能不全,其机制可能与炎症和氧化应激有关。

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.

GIS-based analysis of population exposure to PM2.5 air pollution-A case study of Beijing

PM_（2.5）, formally defined as particulate matter with diameter less than 2.5 μm, is one of most harmful air pollutants threatening human health. Numerous epidemiological studies have shown that both short-term and long-term exposures to PM_（2.5） are strongly linked with respiratory diseases. In this study, various types of spatio-temporal data were collected and used to estimate the spatio-temporal variation of PM2.5 exposure in Beijing in 2014. The seasonal and daily variation of the population-weighted exposure level（PWEL） in 2014 was estimated and compared. The results show that the population exposure to ambient air pollution differs significantly in the four seasons, and the exposure levels in winter and spring are notably higher than the other seasons; the exposure level changes greatly from North to South, and each sub-district maintains similarity to neighboring sub-districts.

Indoor distribution and personal exposure of cooking-generated PM2.5 in rural residences of China:A multizone model study

The fine particulate matter(PM2.5)emitted during cooking is a significant contributor to household air pollution in rural China,resulting in millions of premature deaths annually.Since cooking is an internal pollution source,the indoor concentration of cooking-generated PM2.5 can vary among different rooms in multizone rural residences.This study provides a comprehensive understanding of indoor PM2.5 from cooking in rural residences by utilizing on-site investigations to gather information on cooking behavior and dwelling layout in three Chinese villages,and subsequently simulating indoor spatiotemporal concentrations of cooking-generated PM2.5 using a multizone model.Our findings indicate that the type of zone significantly influences the zonal concentration of PM2.5,with the highest concentrations found in kitchens(i.e.,13.9 to 188.0μg/m3)and lowest in non-adjacent zones to the kitchen(i.e.,0.01 to 7.5μg/m3)among all the modeled conditions.More importantly,the study also assesses the resulting personal exposures for occupants with different time-spent patterns,revealing that the main cook at home and preferring to stay in the adjacent rooms to the kitchen are at the highest risk for personal exposure.The highest personal exposure levels of cooking-generated PM2.5 are 28.5±30.1μg/m3,which is 34 times that of occupants who stay away from the kitchen.The study provides a deeper scientific insight into the indoor spatial distribution and personal exposure to cooking-generated PM2.5 in rural residences,which is crucial for developing effective interventions to mitigate the detrimental health impacts of household air pollution in rural areas.

硅藻土矿开采区颗粒物浓度特征分布及环境健康风险评价研究

选择位于白山市六道沟镇山区典型的硅藻土矿点及晾坯场,采用野外现场监测结合健康风险评价的分析方法,研究了硅藻土矿点和晾坯场内工况条件下PM 2.5和PM 10的浓度特征,依据WHO环境空气准则值、美国和中国AQI指数对硅藻土矿点和坯场进行了健康风险评估.结果表明:静态工况时,矿点内PM 2.5浓度均值是(30.2±0.53)μg/m^3,PM 10的浓度均值是(152.47±0.46)μg/m^3;坯场PM 2.5浓度均值是(32.4±0.32)μg/m^3,PM 10浓度均值是(79.7±0.69)μg/m^3.动态工况时,矿点PM 2.5和PM 10的均值分别为(197.4±32.5)μg/m^3和(3 055.4±205.6)μg/m^3;坯场PM 2.5和PM 10的均值分别为(139±44.6)μg/m^3和(2 195.4±135.2)μg/m^3.矿区颗粒物暴露水平,静态工况时,矿点PM 2.5和PM 10分别为30.2μg/m^3和152.5μg/m^3,坯场PM 2.5和PM 10分别为32.4μg/m^3和79.7μg/m^3;动态条件时,矿点PM 2.5和PM 10分别为98.7μg/m^3和1 527.7μg/m^3,坯场PM 2.5和PM 10分别为69.5μg/m^3和1 097.7μg/m^3.环境健康风险评价结果表明:动态工况时(短期暴露),矿点和坯场PM 10和PM 2.5浓度远超IT-1目标;矿点和坯场PM 10的AQI指数均已超出指数上限(爆表),而PM 2.5的AQI指数也依次为很不健康和不健康、重度污染和中度污染.静态工况时(较长期暴露),矿点和坯场PM 2.5浓度实现IT-3目标,矿点PM 10小于IT-2,坯场PM 10高于IT-1;矿点和坯场PM 2.5和PM 10的AQI指数分别为二级(适中)和三级(轻度污染)、二级(良).

Characterization of personal exposure concentration of fine particles for adults and children exposed to high ambient concentrations in Beijing, China

In China, the health risk from overexposure to particles is becoming an important public health concern. To investigate daily exposure characteristics to PM 2.5 with high ambient concentration in urban area, a personal exposure study was conducted for school children, and office workers in Beijing, China. For all participants （N = 114）, the mean personal 24-hr exposure concentration was 102.5, 14.7, 0.093, 0.528, 0.934, 0.174 and 0.703 μg/m 3 for PM 2.5 , black carbon, Mn, Al, Ca, Pb, and Fe. Children’s exposure concentrations of PM 2.5 were 4–5 times higher than those in related studies. The ambient concentration of PM 2.5 （128.5 μg/m 3 ） was significantly higher than the personal exposure concentration （P 0.05）, and exceed the reference concentration （25 μg/m 3 ） of WHO air quality guideline. Good correlation relationships and significant differences were identified between ambient concentration and personal exposure concentration. The relationships indicate that the ambient concentration is the main factor influencing personal exposure concentration, but is not a good indicator of personal exposure concentration. Outdoor activities （commute mode, exposure to heating, workday or weekend travel） influenced personal exposure concentrations significantly, but the magnitude of the influence from indoor activities （exposure to cooking） was masked by the high ambient concentrations.

Exposure to air pollutants in Vietnam:Assessing potential risk for tourists

Tourism can form an important component of a nation＇s GDP, and Vietnam is among the most visited countries in Southeast Asia. Most studies on personal exposure focus on the general population, or occupational cohorts with exposure to specific pollutants. However, short-term exposure to air pollutants while visiting regions with high levels of air pollution can lead to acute health effects. A personal exposure study was conducted across three cities in Vietnam to estimate exposure to particulate matter （PM2.5） and black carbon for tourists. Measurements were conducted during the wet season in 2014 in Ho Chi Minh City, Da Lat and Nha Trang using portable instrumentation. Average 24-hr PM2.5 and BC exposures were estimated as 18.9 ± 9.24 and 3.41 ± 1.33 μg/m3 and among the three cities, Ho Chi Minh was found to have the highest PM2.5 concentrations. Environmental tobacco smoke, commuting and street food stands were found to contribute to highest levels of exposure to PM2.s and BC across all cities.

Epitranscriptomic 5-Methylcytosine Profile in PM_(2.5)-induced Mouse Pulmonary Fibrosis

Exposure of airborne particulate matter(PM)with an aerodynamic diameter less than 2.5μm(PM2.5)is epidemiologically associated with lung dysfunction and respiratory symptoms,including pulmonary fibrosis.However,whether epigenetic mechanisms are involved in PM2.5-induced pulmonary fibrosis is currently poorly understood.Herein,using a PM2.5-induced pulmonary fibrosis mouse model,we found that PM2.5 exposure leads to aberrant mRNA5-methylcytosine(m5C)gain and loss in fibrotic lung tissues.Moreover,we showed the m5C-mediated regulatory map of gene functions in pulmonary fibrosis after PM2.5 exposure.Several genes act as m5C gain-upregulated factors,probably critical for the development of PM2.5-induced fibrosis in mouse lungs.These genes,including Lcn2,Mmp9,Chi3l1,Adipoq,Atp5j2,Atp5l,Atpif1,Ndufb6,Fgr,Slc11 a1,and Tyrobp,are highly related to oxidative stress response,inflammatory responses,and immune system processes.Our study illustrates the first epitranscriptomic RNA m5C profile in PM2.5-induced pulmonary fibrosis and will be valuable in identifying biomarkers for PM2.5 exposure-related lung pathogenesis with translational potential.