Response of fine particulate matter to reductions in anthropogenic emissions in Beijing during the 2014 Asia–Pacific Economic Cooperation summit

研究使用全球大气化学传输模式GEOS-Chem高分辨率(1/4°×5/16°)区域嵌套版本评估2014年亚洲-太平洋经济合作峰会(APEC)期间不同地区不同污染物减排对北京地区PM_(2.5)(粒径小于2.5μm的气溶胶颗粒,本文中定义为硫酸盐、硝酸银、铵盐、一次有机碳和黑碳气溶胶浓度之和)浓度降低的不同影响。在2014年10月15日至11月29日期间,模拟结果表明:模式可以重现观测结果中PM_(2.5)及主要气态污染物(一氧化碳、二氧化氮和二氧化硫)浓度的日变化趋势。在APEC期间,模拟PM_(2.5)浓度相比会议前期和会议后期下降55.9%–58.5%,与观测结果具有较好的一致性。敏感性实验结果表明:APEC期间华北地区氮氧化物和一次有机碳的减排对于北京地区PM_(2.5)浓度的降低影响最为显著,相应减排措施致使北京地区PM_(2.5)浓度分别下降5.7%和4.6%。同时,对氨气排放的控制可以有效地降低整个华北地区在APEC期间的PM_(2.5)浓度。

Impact of Winter Transit Air Masses on the Sources and Composition Characteristics of Atmospheric Pollution in Hengyang

Through the integration and analysis platform of particulate matter components,a preliminary comparison was conducted on the pollution contribution of the three winter transit air masses in December to environmental quality,and the changes and related relationships of water-soluble ions and particulate matter elements were analyzed.The results showed that winter transit air masses had a significant impact on the air quality in Hengyang.In the quantitative comparison of the primary pollutant contribution during the transit period of air masses,local sources and transit sources each accounted for half,and the impact of transit source on ambient air quality was much greater than that of seasonal base increase.Fine particulate matter was closely related to secondary ions,and particulate matter was closely related to primary ions.The transit of air masses promoted the improvement of secondary ion conversion rate,and the unit increment of fine particulate matter was greater than that of particulate matter.During the transit period,the mass concentrations of most water-soluble ions and most particulate matter elements maintained synchronous growth,with a superimposed effect.The composition ratio of organic carbon and nitrate ions increased,while the composition ratio of ammonia and sulfate ions decreased.Both disposable ions and secondary conversions in the composition of PM_(2.5)had increases and decreases.The high conversion rate of nitrate and the high composition ratio of ammonia radical in Hengyang indicated that transportation source factors had a significant impact on the local environmental quality of Hengyang.

Fine Particulate Matter and Heavy Metals Pollution Status in Ambient Air of Some Selected Industrial Sites in Northern Nigeria

Fine particulate matter and eight heavy metals (Ni, Co, Cu, Pb, Cd, Cr, Mn, and Zn) concentrations were determined in air samples collected from three industrial sites in northern Nigeria using a Handheld Portable Particle Counter for PM2.5 and PM10 with model number CW-HAT 200 and a High Volume Respirable Dust Sampler (APM 460 NL) in conjunction with an Atomic Absorption Spectrophotometer (Serial No. AA0904M046) Flame Test. The results of the fine particulates ranged from 11.0 - 46.0 μg.m-3 for PM2.5 and 22.0 - 88 μg.m-3 for PM10 across all the industrial sites investigated. Most of these results exceeded the WHO permissible levels of 25.0 μg.m-3 and 50.0 μg.m-3 for PM2.5 and PM10 and thus pose threats to people living and working close to these sites. The concentration of the heavy metals studied were found to be within WHO/EU set standards except for the concentrations of Ni, Pb, and Cd that exceeded the set standard by WHO/EU with toxicity potential >1 in the Terytex industry, Kano and Grand Cereals, Jos. Strong positive correlations were found between the fine particulates concentrations and heavy metals in all the studied sites suggesting that common anthropogenic sources contributed to the fine particulates and heavy metals recorded from the industrial areas. We suggested the installation of electrostatic precipitators to combat fine particulates emission from the stack and also recommended a proper legislative framework by the government to regulate and control industrial fugitive emissions to protect human health.

Chemical and Morphological Characteristics of Particulate Matter Suspended in the Air of the Dhaka University Area of Bangladesh

Total suspended particulate matter (SPM) in the urban atmosphere of Dhaka city was collected using a high volume sampling technique for a period of one month (August 2017-September 2017). Chemical characterization of particulate matter (PM) was investigated, and characterized concerning the size distribution, morphological features such as count, total area, average size, perimeter, circularity, aspect ratio (AR), roundness;equivalent spherical diameter (ESD), surface area and volume of PM. The results of elemental analysis showed that the presence of heavy metal in PM was ten to hundred times higher than the standard value prescribed by WHO and USEPA. Several morphological analysis indicated that particles varying in shape from nearly spherical to various irregular shape, had higher surface energy, higher content of Cl and S bearing particles and had a large surface area which can cause greater damage to lungs. The presence of various organic compounds containing functional groups like alcohols, ketones aldehydes, carboxylic acids as well as unsaturated and saturated carbon bonds was observed by FT-IR analysis. Scanning Electron Microscopy (SEM) was used to characterize the morphology of the PM. Agglomerates and shoots type particles were mostly seen in SPM.

The Quantum Microverse: A Prime Number Framework for Understanding the Universe

This study aims to demonstrate a proof of concept for a novel theory of the universe based on the Fine Structure Constant (α), derived from n-dimensional prime number property sets, specifically α = 137 and α = 139. The FSC Model introduces a new perspective on the fundamental nature of our universe, showing that α = 137.036 can be calculated from these prime property sets. The Fine Structure Constant, a cornerstone in Quantum Electrodynamics (QED) and Quantum Chromodynamics (QCD), implies an underlying structure. This study identifies this mathematical framework and demonstrates how the FSC model theory aligns with our current understanding of physics and cosmology. The results unveil a hierarchy of α values for twin prime pairs U{3/2} through U{199/197}. These values, represented by their fraction parts α♊ (e.g., 0.036), define the relative electromagnetic forces driving quantum energy systems. The lower twin prime pairs, such as U{3/2}, exhibit higher EM forces that decrease as the twin pairs increase, turning dark when they drop below the α♊ for light. The results provide classical definitions for Baryonic Matter/Energy, Dark Matter, Dark Energy, and Antimatter but mostly illustrate how the combined α♊ values for three adjacent twin primes, U{7/5/3/2} mirrors the strong nuclear force of gluons holding quarks together.

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.

Effect of Long-term exposure to fine particulate matter air pollution on hypertension incidence:a systematic review and meta-analysis of cohort studies

Objective Studies of the association of hypertension with long-term exposure to particulate matter less than 2.5μm in diameter(PM2.5)have shown contradictory results and the magnitude of the association is still unclear.Hence,we conducted a meta-analysis of cohort studies to assess the effect of long-term exposure to PM2.5 on incident hypertension.

Development of Advanced Biomass Cookstove and Performance Comparisons Using the Modified Star Rating Methodology

A disruptive approach to a fundamental process has been applied in a biomass combustion device with two variable speed fans to supply air for gasification and another for combustion processes,separately.Besides,the preheating of secondary air,required for combustion process was also ensured through annulus chamber before being fed into the combustion chamber.The turbulent flow and homogenous mixing were also ensured by controlling the flow rate resulting in the reduced emissions of carbon monoxide(CO)and fine particulate matter(PM 2.5,particulate matter having aerodynamic diameter<2.5 micron).The design approach applied here has also ensured the homogeneous mixing of preheated air with the volatiles,resulted in cleaner combustion.This arrangement has led to the emissions of PM2.5 and CO much better than those of the earlier cookstove models,and very close to that of a liquefied petroleum gas(LPG)stove.Further,the comparative analysis based on the modified star rating of total 15(14 are biomass and another LPG)cookstove models tested using the same standard methodology has been done and presented in this study.Based on the star rating,the performance of the LPG stove was found to be best and assigned as a 5-star product followed by the IITD model(4-star),while the other 13 models got different ratings starting from 1-star to 3-star,respectively.Also,the thermal performance of the IITD cookstove model is found to be the highest,while the emission characteristics are found to be the least among all biomass cookstove models,presented here.

The Effect of Urban Agglomeration Expansion on PM_(2.5) Concentrations: Evidence from a Quasi-natural Experiment

This study constructs a quasi-natural experiment based on the expansion of the Yangtze River Delta urban agglomeration(YRDUA) of China in 2010 to investigate the impact and inner mechanism of urban agglomeration expansion on fine particulate matter(PM_(2.5)) concentrations through propensity scores in difference-in-differences models(PSM-DID) using panel data from 286 prefecturelevel cities in China from 2003 to 2016. The results show that 1) urban agglomeration expansion contributes to an overall decrease in PM_(2.5)concentration, which is mainly achieved from the original cities. For the new cities, on the other hand, the expansion significantly increases the local PM_(2.5)concentration. 2) In the long term, the significant influence of urban agglomeration expansion on PM_(2.5)concentration lasts for three years and gradually decreases. A series of robustness tests confirm the applicability of the PSM-DID model.3) Cities with weaker government regulation, a better educated population and higher per capita income present stronger PM_(2.5)reduction effects. 4) Urban agglomeration expansion affects the PM_(2.5)concentration mainly through industrial transfer and population migration, which cause a decrease in the PM_(2.5)concentration in the original cities and an increase in the PM_(2.5)concentration in the new cities.Corresponding policy suggestions are proposed based on the conclusions.

含细颗粒悬浮物矿井水的混凝沉淀参数优化

针对宝日希勒露天煤矿矿井水中悬浮颗粒物粒径小、难去除的问题,采用单因素与正交实验方法确定了混凝沉淀工艺的最佳参数,分析了矿井水中细颗粒物的混凝机理。结果表明,混凝沉淀的最佳工艺参数为聚合氯化铝(PAC)投加量50 mg/L,非离子型聚丙烯酰胺(NPAM)投加量5.0 mg/L,快速搅拌(300 r/min)时间1 min,慢速搅拌(50 r/min)时间8 min,静置时间5 min;在最佳工艺条件下,悬浮物(SS)质量浓度为5.0 mg/L,去除率为99.1%,相比单独投加PAC时,10μm以下的细颗粒物去除率提高了25.9%,矿井水的ζ电位由-40.9 mV降低至-16.3 mV,说明细颗粒物的混凝机理主要为PAC吸附电中和作用和聚丙烯酰胺(PAM)吸附架桥作用。

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。

我国城市地区PM_(2.5)和O_(3)污染相关性:2017~2022年时空演变特征与协同防控启示

基于2017~2022年全国地级及以上城市空气质量监测数据及各省(自治区、直辖市)污染排放数据,计算PM_(2.5)日均浓度(DA PM_(2.5))和O_(3)日最大8h滑动平均值(MDA8_O_(3))间的皮尔逊相关系数(R_(p)),分区域分时段研究了二者相关性的时空变化特征,从污染排放等方面分析其原因.结果表明:从时空变化上看,全国范围内DA PM_(2.5)和MDA8_O_(3)第一、四季度在统计上无显著相关性(R_(p)=-0.11~0.03),仅西南、华南地区为正相关(R_(p)=0.11~0.32).全国范围内DA PM_(2.5)和MDA8O_(3)在第二季度(R_(p)=0.26~0.36)、第三季度(R_(p)=0.46~0.55)呈正相关,汾渭平原及西北地区在部分年份不相关.污染排放是影响PM_(2.5)和O_(3)污染相关性的主要因素.从时间变化上看,全国和各区域一次PM_(2.5)、二氧化硫排放特征值(ECV_(PM_(2.5))、ECV_(SO_(2)))下降而氮氧化物、挥发性有机物排放特征值(ECVNOx和ECVVOCs)上升,这与大部分省(自治区、直辖市)R_(p)平均值上升的趋势一致.从空间分布上看,在ECVPM_(2.5)和ECVSO2低而ECV_(NOx)和ECV_(VOCs)高的地区,PM_(2.5)与O_(3)污染正相关性较强.提出全国不同区域差异化的污染防控启示.京津冀及周边、长三角、东北和西南地区(第二、三季度)以及华南地区(全年),需关注NO_(x)和VOCs排放控制.京津冀及周边、长三角、东北和西南地区(第一、四季度)以及汾渭平原和西北地区(全年),需加强一次PM_(2.5)污染减排.

亚慢性PM_(2.5)和O_(3)共同暴露对大鼠鼻黏膜ATP总量及ATP酶活性的影响

目的:探讨细颗粒物(fine particle matter,PM_(2.5))和臭氧(ozone,O_(3))亚慢性共同暴露对大鼠鼻黏膜组织腺嘌呤核苷三磷酸(adenosine triphosphate,ATP)总量及ATP酶活性的影响。方法:采用随机数字表法将20只雄性Sprague Dawley(SD)大鼠均分为对照组和暴露组,每组各10只,分别饲养于常规清洁级环境和本团队既往所搭建的大气污染物暴露系统中,连续暴露208 d。暴露期间,监测暴露系统内PM_(2.5)和O_(3)浓度,采用自测和站点数据相结合的方法对暴露系统内PM_(2.5)和O_(3)进行综合评估。在暴露第208天处死大鼠取心、肝、脾、肾、睾丸等主要器官和鼻黏膜组织,称量各脏器重量并计算脏器系数。利用所收集鼻黏膜组织,使用生物发光法测定ATP总量,使用分光光度法检测Na^(+)-K^(+)-ATP酶和Ca^(2+)-ATP酶活性。使用两独立样本t检验比较各指标组间差异。结果:自第3周开始至暴露结束,暴露组大鼠体质量高于对照组(P<0.05),两组间脏器系数差异无统计学意义。暴露组日均PM_(2.5)浓度为(30.68±19.23)μg/m3,O_(3)最大8 h浓度(O_(3)-8 h)为(82.45±35.81)μg/m3。暴露组大鼠鼻黏膜组织ATP化学发光值(792.4±274.1)IU/L低于对照组(1126.8±218.1)IU/L,鼻黏膜组织Na^(+)-K^(+)-ATP酶活性(1.53±0.85)U/mg低于对照组(4.31±1.60)U/mg(P<0.05)。对照组和暴露组鼻黏膜组织的蛋白含量分别为(302.14±52.51)mg/L和(234.58±53.49)mg/L,Ca^(2+)-ATP酶活性分别为(0.81±0.27)U/mg和(0.99±0.73)U/mg,组间差异均无统计学意义。结论:亚慢性PM_(2.5)和O_(3)共同暴露可能影响大鼠鼻黏膜组织供氧能力。

同位素结合PMF模型解析珠三角PM_(2.5)来源研究

二次气溶胶是大气细颗粒物(PM_(2.5))中最多的组分,客观识别其来源是PM_(2.5)源解析的难点,也是精确控制PM_(2.5)污染来源的关键。本研究在广东省鹤山超级大气监测站采集了76个PM_(2.5)样品,分析了其碳质组分(元素碳和有机碳)、水溶性离子(SO_(4)^(2-)、NH4^(+)、K^(+)、Ca^(2+)、Cl^(-)、Na^(+)、Mg^(2+)、NO_(2)^(-)和NO_(3)^(-))和金属元素(Fe、Cr、Cu、Mn、Ni、Pb、V、Zn、Cd、As)共20种化学组分,测定了7个PM_(2.5)代表样品的总碳(TC)放射性碳(^(14)C)。基于PM_(2.5)化学组分的PMF模型结果显示,生物质燃烧、海盐、土壤扬尘、轮船排放、工业过程、燃煤源和二次气溶胶分别贡献PM_(2.5)的18.98%、4.32%、13.85%、7.61%、14.08%、12.72%和30.03%。基于已发表的δ^(15)N(NO_(3)^(-))、δ^(18)O(NO_(3)^(-))结果,利用贝叶斯模型定量解析了NO_(3)^(-)的来源,并应用线型回归将PMF模型解析的二次气溶胶源再分配给一次颗粒源,结果显示,燃煤源(36.50%)、生物燃料源(29.35%)、土壤扬尘+海盐源(21.00%)和移动源(13.15%)是珠三角PM_(2.5)的主要来源。二次分配后PMF模型结果中TC的非化石源贡献与基于^(14)C结果的相对误差小于9%,说明PMF模型能很好地捕获PM_(2.5)主要贡献源,并且较准确地源解析珠三角的PM_(2.5),研究结果可为区域污染防治政策措施的制定提供科学依据。

大气细颗粒物PM_(2.5)致Wistar大鼠肺部病变的研究

目的探讨大气细颗粒物(particulate matter,PM)PM_(2.5)致肺部病变机制。方法采用实时PM_(2.5)采集器进行PM_(2.5)收集,Wistar大鼠饲养于PM_(2.5)的全身暴露染毒系统,Wistar大鼠每日染毒4小时,共染毒9月,设立实验组及对照组;观察肺组织大体结构及HE染色观察;流式细胞术检测Wistar大鼠T细胞免疫功能、肺组织细胞凋亡、细胞周期及DNA指数;ELISA实验检测Wistar大鼠血清及肺灌洗液中CEA、CA125及Scc Ag表达水平。结果实验组肺组织以支气管向外周辐射状颜色发暗、偏黑,多处可见白色斑点和泡状凸起,边缘不规则白色隆起;HE染色结果,实验组肺组织纤维化,肺实变严重,肺泡充血,见大量炎性反应增生;实验组CD4/CD8比值显著高于对照组(P<0.05),血清及肺灌洗液中CA125的表达显著高于对照组(P<0.05),实验组肺组织细胞凋亡率显著低于对照组,而DNA指数显著增高(均P<0.05)。结论长期接触PM_(2.5)会造成肺组织出现不同程度结节,肺组织出现大范围炎性反应病变。

大气细颗粒物有机成分在体染毒对大鼠胸主动脉血管反应的影响及其与NO/NOS的关系

目的探究大气细颗粒物PM2.5有机成分在体染毒对大鼠胸主动脉血管反应性的影响及其与血管内皮细胞NO/NOS系统的关系。方法 Wistar大鼠随机分为两组:①染毒组:PM2.5染毒溶液1 ml.kg-1.d-1,iv;②对照组:生理盐水1 ml.kg-1.d-1,iv。染毒10 d后,击晕大鼠,主动脉采血,用于检测血清一氧化氮(NO)和内皮型一氧化氮合酶(eNOS)含量、诱导型一氧化氮合酶(iNOS)活性。分离主动脉,用于离体主动脉实验和免疫组织化学染色分析,观察主动脉血管反应性和内皮细胞eNOS和iNOS蛋白表达。结果 PM2.5有机成分在体染毒后,可增强大鼠离体胸主动脉对60 mmol·L-1 KCl及苯肾上腺素(PE,10-5 mol·L-1)的收缩效应,减弱其对乙酰胆碱(ACh,10-9～10-5 mol·L-1)的舒张效应,但主动脉对硝普钠(SNP,10-9～10-5 mol·L-1)的舒张效应则不受影响。PM2.5有机成分在体染毒后,大鼠血清NO含量及iNOS活性增加,但eNOS含量则无明显变化;主动脉血管内皮细胞iNOS表达增加,eNOS表达减少。结论 PM2.5有机成分可影响大鼠胸主动脉环血管反应性,NO/NOS系统功能紊乱可能是其机制之一。

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.

河南省大气细颗粒物暴露与小于胎龄儿的发病风险关系

目的:探讨大气细颗粒物(PM2.5)及其组分与小于胎龄儿(SGA)发病风险的关联。方法:基于国家免费孕前优生健康检查数据库2013年河南省的母婴数据进行分析,使用logistic回归模型分析孕妇妊娠各时期PM2.5及其组分暴露对SGA的影响。结果:在调整一般人口学资料、生活方式和健康行为、妊娠情况和环境温度变量后,以第一分位数PM2.5浓度为参照,孕早期、孕中期、孕晚期和全孕期暴露于第四分位数PM2.5浓度分娩SGA的风险分别增加58.2%(OR=1.582,95%CI 1.44~1.738)、35.4%(OR=1.354,95%CI 1.235~1.483)、30.1%(OR=1.301,95%CI 1.189~1.423)和45.9%(OR=1.459,95%CI 1.363~1.561)。以第一分位数浓度暴露为参照,全孕期黑炭、有机物、铵盐、硝酸盐和硫酸盐第四分位数浓度暴露与分娩SGA风险增加均有关(P<0.05)。结论:妊娠各时期孕妇避免PM2.5暴露均能降低SGA发生风险。

基于双重差分法的宁夏大气PM_(2.5)长期暴露对呼吸系统疾病死亡影响的研究

目的了解宁夏2010—2015年呼吸系统疾病死亡情况和PM_(2.5)的分布状况,探讨宁夏大气PM_(2.5)长期暴露对居民呼吸系统疾病死亡的影响。方法收集2010—2015年宁夏居民死亡监测数据,各街道、乡镇大气PM_(2.5)年均浓度以及气象、人口、地理信息等相关资料。采用改良的双重差分设计(广义非线性模型拟合),分析大气PM_(2.5)长期暴露对呼吸系统疾病死亡的影响。结果在呼吸系统疾病死亡人群中,男性占比55.36%,女性比占44.63%;64岁及以下组占比14.21%,65岁及以上组占比85.79%;大气PM_(2.5)浓度每升高1μg/m 3,对呼吸系统疾病和下呼吸道疾病死亡的OR值及95%置信区间(CI)分别为1.03(1.02~1.04)、1.03(1.02~1.05)。分层分析结果显示,大气PM_(2.5)浓度每升高1μg/m 3,对男性和女性呼吸系统疾病死亡的OR及95%CI分别为1.03(1.02~1.04)和1.03(1.02~1.05);对年龄≤64岁及年龄≥65岁组呼吸系统疾病死亡的OR及95%CI分别为1.02(0.99~1.05)和1.03(1.02~1.04)。结论宁夏地区大气PM_(2.5)长期暴露增加人群呼吸系统疾病、下呼吸道疾病死亡的风险,男性和女性均为敏感人群,年龄≥65岁组人群更加敏感。

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。