Adverse Effects of Exposure to Fine Particulate Matters and Ozone on Gestational Hypertension

Gestational hypertension(GH)is a common complication during pregnancy.GH is regarded as a potential public health challenge for pregnant women and infants.Limited evidence has linked ambient air pollution to an increased GH risk.However,most of the studies were conducted in developed countries,with inconsistent results obtained.The present study was performed to explore whether exposure to particulate matters with an aerodynamic diameter≤2.5(PM2.5)and ozone(O3)was related to elevated odds of GH in a Chinese population.This population-based cohort study involved 38115 pregnant women in Wuhan,China.All information was collected from the Wuhan Maternal and Child Health Management Information System,using standardized quality control.The daily air pollutant data for PM2.5 and O3 were obtained from the 20 monitoring stations of the Wuhan Environmental Monitoring Center during 2014.The nearest monitor approach was applied to individual exposure assessment of PM2.5 and O3 for each participant.After adjusting for major confounders and other air pollutants,a 10μg/m^3 increase in PM25 and O3 concentrations was found to correlate to a 1.14-fold[95%confidence interval(95%CI):1.09,1.20]and a 1.05-fold(95%CI:1.02,1.07)increase in GH risk,respectively.Additionally,stronger relationships between GH risk and PM25 and O3 exposure were observed in women who conceived in winter and summer,respectively.These findings suggest that air pollutants may contribute to the development of GH.

Changes on Stroke Burden Attributable to Ambient Fine Particulate Matter in China

Objective In recent decades,China has implemented a series of policies to address air pollution.We aimed to assess the health effects of these policies on stroke burden attributable to ambient fine particulate matter(PM_(2.5)).Methods Joinpoint regression was applied to explore the temporal tendency of stroke burden based on data from the Global Burden of Disease 2019 study.Results The age-standardized rates of disability-adjusted life year(DALY)for stroke attributable to ambient PM2.5 in China,increased dramatically during 1990-2012,subsequently decreased at an annual percentage change(APC)of-1.98[95% confidence interval(CI):-2.26,-1.71]during 2012-2019.For ischemic stroke(IS),the age-standardized DALY rates doubled from 1990 to 2014,and decreased at an APC of-0.83(95%CI:-1.33,-0.33)during 2014-2019.Intracerebral hemorrhage(ICH)showed a substantial increase in age-standardized DALY rates from 1990 to 2003,followed by declining trends,with APCs of-1.46(95%CI:-2.74,-0.16)during 2003-2007 and-3.33(95%CI:-3.61,-3.06)during 2011-2019,respectively.Conversely,the age-standardized DALY rates for subarachnoid hemorrhage(SAH)generally declined during 1990-2019.Conclusion Our results clarified the dynamic changes of the ambient PM_(2.5)-attributable stroke burden in China during 1990-2019,highlighting the health effects of air quality improvement policies.

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.

Analysis of Sources of Atmospheric Fine Particulates in Nan'ao County

Based on on-line single particle aerosol mass spectrometry （SPAMS） with high time resolution, the sources of atmospheric fine particu- late matter in Nan＇ao County were analyzed. The results showed that during the monitoring period from March 24 to 27 in 2015, the primary source of fine particulate matter in Nao＇ao County was motor vehicle exhaust, that is, 24.7% of fine particulates were from motor vehicle exhaust, followed by biomass burning （17.2%）, fire coal （17.2%）, and sea salt （13.3%）. The proportions of fire coal and sea salt revealed the peculiarity of sources of atmospheric fine particulate matter in Nan＇ao County. Therefore, it is suggested that some measures should be adopted to limit tourist traffic to reduce the adverse impact of motor vehicle exhaust on ambient air quality in Nan＇ao County.

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.

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

The nested-grid capability of the global chemical transport model GEOS-Chem, with a horizontal resolution of 1/4°× 5/16° （latitude x longitude）, was used to identify the chemical species whose reductions made the largest contributions to decreases in PM2.s concentrations （fine particulate matter, diameter 〈 2.5μm, defined in this study as the sum of sulfate, nitrate, ammonium, black carbon, and organic carbon aerosols） in Beijing during the 2014 Asia-Pacific Economic Cooperation （APEC） summit. A number of numerical experiments were carried out for the period 15 October-29 November 2014. The model reproduced the observed daily variations of concentrations of PM2.s and gas-phase species （carbon monoxide, nitrogen dioxide, and sulfur dioxide）. Simulated PM2.s concentrations decreased by 55.9%-58.5% during the APEC period, compared to other periods in October and November 2014, which agreed closely with measurements. Sensitivity results showed that emissions control measures regarding nitrogen oxides and organic carbon over North China led to the largest reductions in PM2.s concentrations in Beijing during the APEC summit, which led to overall reductions in the PM2.5 concentration of Beijing by 5.7% and 4.6%, respectively. The control of ammonia emissions was found to be able to greatly reduce PM2.5 concentrations in the whole of North China during the APEC meeting.

Physical activity, long-term fine particulate matter exposure and type 2 diabetes incidence: A prospective cohort study

Background: Despite the adverse effects of ambient fine particulate matter (PM_(2.5) ) on type 2 diabetes and the beneficial role of physical activity (PA), the influence of PM_(2.5) on the relationship between PA and type 2 diabetes remains unclear.Methods: In this prospective study with 71,689 participants, PA was assessed by a questionnaire and was categorized into quartiles for volume and three groups for intensity. Long-term PM_(2.5) exposure was calculated using 1-km resolution satellite-based PM_(2.5) estimates. PM_(2.5) exposure and PA's effect on type 2 diabetes were assessed by cohort-stratified Cox proportional hazards models, individually and in combination.Results: In 488,166 person-years of follow-up, 5487 incident type 2 diabetes cases were observed. The association between PA and type 2 diabetes was modified by PM_(2.5) . Compared with the lowest quartile of PA volume, the highest quartile was associated with reduced type 2 diabetes risk in low PM_(2.5) stratification (≤65.02 μg/m^(3)) other than in high PM_(2.5) stratification (>65.02 μg/m^(3)), with the hazard ratio (HR) of 0.75 (95% confidence interval [CI]: 0.66-0.85) and 1.10 (95% CI: 0.99-1.22), respectively. Similar results were observed for PA intensity. High PM_(2.5) exposure combined with the highest PA levels increased the risk of type 2 diabetes the most (HR= 1.79, 95% CI: 1.59-2.01 for PA volume;HR = 1.82, 95% CI: 1.64-2.02 for PA intensity).Conclusion: PA could reduce type 2 diabetes risk in low-pollution areas, but high PM_(2.5) exposure may weaken or even reverse the protective effects of PA. Safety and health benefits of PA should be thoroughly assessed for long-term polluted residents.

Warthin-starry Silver Method Showing Particulate Matter in Macrophage

Objective To verify whether Warthin-Starry （WS） silver method could detect the air particulate matter （PM）/dust particles （Ps） located within the macrophages in situ. Methods There were 26 autopsy cases that resulted from cerebral hemorrhage （group A）, silicosis （group B）, and fetal death during pregnancy （group C）. Samples were collected separately and serial sections were prepared from the lungs and lymph nodes and stained with hematoxylin and eosin （HE）, WS silver, immunohistochemistry of CD68. Furthermore, ultrathin sections were taken from the WS positive serial sections of groups A and B. Ps were observed under a transmission electron microscope （TEM） and the elements of Ps were measured by X-ray spectrum analysis （X-RSA）. Results In both groups A and B, WS staining was positive for the larger and fine Ps, the so called ＂dust cells＂, but HE staining was almost negative for fine Ps. In group C, no larger or fine Ps were found. Immunohistochemical staining of CD68 certified that the ＂dust cells＂ containing Ps were macrophages. The results of TEM and X-RSA proved that the structure and elements of Ps belonged to PM indeed. Conclusion WS staining is a better than HE staining in showing the location of PM within macrophages.

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.

Exposure to Fine Particles by Mine Tailing and Lung Function Effects in a Panel of Schoolchildren,Chanaral,Chile

There is much literature on the effects of fine particulate matter (PM2.5) on respiratory and cardiovascular health. However, few studies have evaluated the impact of PM2.5 on a population living in the vicinity of a massive deposit of mine tailings. A longitudinal panel study was performed to evaluate the association between exposure to PM2.5 and acute effects on lung function in schoolchildren from November 2012 to May 2013. Ambient levels of PM2.5 and its metal composition were measured. Lung function was evaluated using spirometric testing. Associations were quantified using GEE multilevel analysis controlling for confounders by using different lag time periods. The chemical characterization of PM2.5 had high levels of S > Na > Cl > Ca > Si > Fe > Al > Mg > K > Cu > Ti > and Zn, which would be associated with metals present in tailings. We found a negative association between the temporal variation of PM2.5 and changes in lung function specifically on forced vital capacity. Our results suggest that schoolchildren exposed to fine particulate matter from tailings deposited in the bay of Chanaral have their forced vital capacity decreased, which would affect their present and future lung development, increasing the risk of developing chronic respiratory diseases.

Ambient fine particulate matter and cardiopulmonary health risks in China

In China, the level of ambient fine particulate matter (PM_(2.5)) pollution far exceeds the air quality standards recommended by the World Health Organization. Moreover, the health effects of PM_(2.5) exposure have become a major public health issue. More than half of PM_(2.5)-related excess deaths are caused by cardiopulmonary disease, which has become a major health risk associated with PM_(2.5) pollution. In this review, we discussed the latest epidemiological advances relating to the health effects of PM_(2.5) on cardiopulmonary diseases in China, including studies relating to the effects of PM_(2.5) on mortality, morbidity, and risk factors for cardiovascular and respiratory diseases. These data provided important evidence to highlight the cardiopulmonary risk associated with PM_(2.5) across the world. In the future, further studies need to be carried out to investigate the specific relationship between the constituents and sources of PM_(2.5) and cardiopulmonary disease. These studies provided scientific evidence for precise reduction measurement of pollution sources and public health risks. It is also necessary to identify effective biomarkers and elucidate the biological mechanisms and pathways involved;this may help us to take steps to reduce PM_(2.5) pollution and reduce the incidence of cardiopulmonary disease.

Fine particulate matter and cardiorespiratory health in China:A systematic review and meta-analysis of epidemiological studies

This review aimed to systematically summarize the epidemiological literature on the cardiorespiratory effects of PM_(2.5)published during the 13^(th) Five-Year Plan period(2016-2020)in China.Original articles published between January 1,2016 and June 30,2021 were searched in PubMed,Web of Science,the China National Knowledge Internet Database and Wanfang Database.Random-or fixed-effects models were used to pool effect estimates where appropriate.Of 8558 records identified,145 met the full eligibility criteria.A 10μg/m^(3) increase in short-term PM_(2.5)exposure was significantly associated with increases of 0.70%,0.86%,0.38%and 0.96%in cardiovascular mortality,respiratory mortality,cardiovascular morbidity,and respiratory morbidity,respectively.The specific diseases with significant associations included stroke,ischemic heart disease,heart failure,arrhythmia,chronic obstructive pulmonary disease,pneumonia and allergic rhinitis.The pooled estimates per 10μg/m^(3) increase in long-term PM_(2.5)exposure were 15.1%,11.9%and 21.0%increases in cardiovascular,stroke and lung cancer mortality,and 17.4%,11.0%and 4.88%increases in cardiovascular,hypertension and lung cancer incidence respectively.Adverse changes in blood pressure,heart rate variability,systemic infiammation,blood lipids,lung function and airway infiammation were observed for either short-term or long-term PM_(2.5)exposure,or both.Collectively,we summarized representative exposure-response relationships between short-and long-term PM_(2.5)exposure and a wide range of cardiorespiratory outcomes applicable to China.The magnitudes of estimates were generally smaller in short-term associations and comparable in long-term associations compared with those in developed countries.Ourfindings are helpful for future standard revisions and policy formulation.There are still some notable gaps that merit further investigation in China.

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.

Experimental Study of the Removal of Fine Particulate Matter and Moisture from Flue Gas

Liquid desiccant systems are promising methods to recover water and waste heat simultaneously from flue gas.Prior research found that the reduction of particulate matter could occur during the absorption processes.In the present paper,experiments were carried out to explore the effect of removing fine particulate matter(PM_(2.5))in a liquid desiccant dehumidifier.Aqueous calcium chloride(CaCl_(2))was used as the desiccant in the experiments.The discrepancies in mass and energy conservation were within±10%and±15%,respectively,which showed the good reliability of the experimental results.Additionally,23.5%–46.0%of the PM_(2.5)and 23.9%–45.1%of the moisture in the flue gas were removed.By comparing the desiccant solution and water,it was found that they could minimally remove PM_(2.5)through washing the flue gas.Regardless of whether the flue gas was dehumidified by water or the solution,the removal fractions of PM_(2.5)of these two methods could be very close if they achieve the same fraction of moisture removal.From the results of a parameter analysis,it was found that the removal fraction of PM_(2.5)was nearly proportional to the removal fraction of moisture within the experimental range.

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.

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.

华北典型农业区PM_(2.5)组分分析与来源解析

华北大气污染区域化正在对农业生态区域产生显著影响,为了了解华北农业地区大气细颗粒物PM_(2.5)的季节分布特征,2017年7月、9月、12月以及2018年4月在中国科学院禹城农业生态综合实验站进行分季节PM_(2.5)样品采集,并测定分析了样品中31种化学成分。结果表明,碳质气溶胶总体的浓度水平为13.11±8.37μg m^(−3),有机碳(OC)冬春季节浓度较高,元素碳(EC)浓度在秋冬季节较高。同时OC/EC的比值在秋季明显偏低,表明在秋季二次碳质气溶胶对PM_(2.5)贡献较小。水溶性离子浓度总体在冬季最高。NO_(3)^(-)/SO_(4)^(2-)比值在夏季明显偏低为0.69,华北地区夏季固定点源对大气污染的贡献相对较高。PM_(2.5)中金属元素以Na、Mg、Al、Ca、K、Fe等地壳元素为主,具有致癌风险的Co、Cr、Ni、Pb、As等金属元素年均浓度为0.32±0.24 ng m^(−3)、5.40±5.42 ng m^(−3)、10.23±7.46 ng m^(−3)、42.23±27.75 ng m^(−3)、5.66±3.79 ng m^(−3)。受体模型(PMF)计算结果表明,PM_(2.5)的主要来源为二次污染源、生物质燃烧源、燃煤燃油源、柴油车尾气和土壤源,贡献率分别达37.1%、18.2%、14.2%、9.4%和7.9%,表明农业区细颗粒物污染受到华北工业、农业与自然排放的多重影响。

Ovarian Damages Produced by Aerosolized Fine Particulate Matter （PM2.5） Pollution in Mice： Possible Protective Medications and Mechanisms

Background： Ambient aerosol fine particulate matter （PM2.5） is associated with male reproductive toxicity in experiments and may have adverse effects in the female. However, studies evaluating the protective effects and precise mechanisms of aspirin, Vitamin C, Vitamin E, or ozone against toxic effects of PM2.5 are sparse. This study was conducted to investigate the possible protective effects and mechanisms of aspirin, Vitamin C, Vitamin E, or ozone on fertility in female mice treated with PM2.5, Methods： Eighty-four ICR mice were divided into six groups： control group, PM2.5 group, PM2.5 ＋ aspirin group, PM2.5 ＋ Vitamin C group, PM2.5 ＋ Vitamin E group, and PM2.5 ＋ ozone group. PM2.5 was given by intratracheal instillation every 2 days for 3 weeks. Aspirin, Vitamin C, and Vitamin E were given once a day by oral gavage for 3 weeks, and ozone was administered by intraperitoneal injection once a day for 3 weeks. The levels ofanti-Mullerian honnone （AMH）, interleukin-6 （IL-6）, tumor necrosis factor-alpha （TNF-α）, and 8-hydroxy-2＇-deoxyguanosine （8-OHdG） were measured using enzyme-linked immunosorbent assay. Western blotting analysis was used to analyze the expressions ofBcl-2, Bax, and caspase-3 in ovaries. Changes in histological structure were examined by light microscope and electron microscopy was used to detect ultramicrostructure. Results： The results demonstrated that PM2.5 decreased AMH levels （P 〈 0.001）; however, aspirin （P 〈 0.001）, Vitamin C （P 〈 0.001）, Vitamin E （P = 0.001）, and ozone （P = 0.002） alleviated the decrease. Changes of IL-6, TNF-α, 8-OHdG, Bax/Bcl-2, and caspase-3 in PM2.5 group were increased compared to control group （P 〈 0.001）, while in PM2.5 ＋ aspirin, PM2.5 ＋ Vitamin C, PM2.5 ＋ Vitamin E, and PM2.5 ＋ ozone groups, they were statistically decreased compared to PM2.5 group （P 〈 0.001 or P 〈 0.05）. Conclusions： PM2.5 cause the damage of ovaries, and aspirin, Vitamin C, Vitamin E, and ozone antagonizes the damage. The protective mechanism is probably due to its ability to blunt the inflammatory and oxidative stress caused by PM2.5, which subsequently suppressing the expression of apoptotic regulatory protein and reducing the incidence of ovary apoptosis.

Long-term trends of fine particulate matter and chemical composition in the Pearl River Delta Economic Zone （PRDEZ）, China

Understanding essential for formulating the trends in PM2.5 levels is clean air plans. This paper analyzes PM2.5 data from various published sources for the years 2000 to 2010 in the Pearl River Delta Economic Zone （PRDEZ）. The long-term variation in PM2.5 mass concentration is analyzed. Results show that PM2.5, organic carbon （OC）, elemental carbon （EC）, and SO24 show a similar trend, increasing before 2005 and then decreasing slightly. The annual average PM2.5 concentra- tion ranges from 49.1 μg·m-3 in 2000 to 64.3 μg·m-3 in 2010, with a peak of 84.1 μg· m3 in 2004. None of these 11 years meets the new National Ambient Air Quality standard （NAAQS） for PM2.5 （35 μg· m-3）. Overall average concentrations of OC, EC, and SO2/4 are 13.0, 6.5, and 11.8μg·m-3, respectively. NO3 and NH＋ respectively have concentrations of 1.5 μg·m-3 and 2.9 μg·m-3 in 2000 and 6.4 μg·m 3 and 5.3μg·m-3 in 2010, with a statistically significant average annual trend of＋ 0.2 μg·m-3 ·yr-1 and ＋ 0.1 μg· m-3. yr-1. In certain geographic regions, OC and EC contribute most of the PM2.5, while in other regions secondary water-soluble ions are more important. In general, OC and SO2/4- are the dominant components of PM2.5, contributing 20.6% and 18.6%, respectively. These results provide, for the first time, a better understanding of the long-term PM2.5 characteristics and trends, on a species-by-species basis, in the PRDEZ. The results indicate that PM2.5 abatement needs to prioritize secondary species.

Fine Particulate Matter-Induced Exacerbation of Allergic Asthma via Activation of T-cell Immunoglobulin and Mucin Domain 1

Background： Fine particulate matter （PM2.5） exacerbates airway inflammation and hyperreactivity in patients with asthma, but the mechanism remains unclear. The aim of this study was to observe the effects of prolonged exposure to high concentrations of PM2.5 on the pathology and airway hyperresponsiveness （AHR） of BALB/c mice undergoing sensitization and challenge with ovalbumin （OVA） and to observe the effects of apoptosis and T-cell immunoglobulin and mucin domain 1 （TIM-1） in this process. Methods： Forty female BALB/c mice were divided into four groups： control group, OVA group, OVA/PM group, and PM group （n - 10 in each group）. Mice in the control group were exposed to filtered clean air. Mice in the OVA group were sensitized and challenged with OVA. Mice in the OVA/PM group were sensitized and challenged as in the OVA group and then exposed to PM2.5 for 4 h per day and 5 days per week for a total of 8 weeks using a nose-only ＂PM2.5 online enrichment system＂ in The Second Hospital of Hebei Medical University. Mice in the PM group were exposed to the PM2.5 online enrichment system only. AHR was detected. Bronchoalveolar lavage fluid （BALF） was collected for cell classification. The levels of interleukin-4 （IL-4）, IL-5, and IL-33 in BALF were measured using enzyme-linked immunosorbent assay. Changes in histological structures were examined by light microscopy, and changes in ultramicrostructures were detected by electron microscopy. Apoptosis was determined by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling （TUNEL） assay in the lung tissues. Western blotting and immunohistochemistry were utilized to analyze the expression of Bcl-2, Bax, and TIM-1 in the lungs. Results： The results showed that AHR in the OVA/PM group was significantly more severe than that in the OVA and PM groups （P 〈 0.05）. AHR in the PM group was also considerably more severe than that in the control group （P 〈 0.05）. The BALF of OVA/PM group （28.00± 6.08 vs. 12.33 ±4.51, t = 4.631, P = 0.002） and PM group （29.00 ± 3.00 vs. 12.33 ± 4.51, t = 4.927, P = 0.001） had more lymphocytes than the BALF of the control group. The number of neutrophils in the BALF of the OVA/PM group （6.67 ± 1.53 vs. 3.33 ± 1.53, t = 2.886, P = 0.020） and PM group （6.67 ± 1.53 vs. 3.33 ± 1.53, t = 2.886, P = 0.020） was much higher than those in the BALF of OVA group （P 〈 0.05）. TUNEL assays showed that the number of apoptotic cells in the OVA/PM group was significantly higher than that in the OVA group （Tunel immunohistochemical scores [IHS%], 1.20 ± 0.18 vs. 0.51 ± 0.03, t = 8.094, P 〈 0.001） and PM group （Tunel IHS%, 1.20 ± 0.18 vs. 0.51 ±0.09, t = 8.094, P〈 0.001）, and that the number of apoptotic cells in the PM group was significantly higher than that in the control group （Tunel IHS%, 0.51 ± 0.09 vs. 0.26 ± 0.03, t = 2.894, P = 0.020）. The concentrations of IL-4 （77.44 ± 11.19 vs. 48.02 ±10.02 pg/ml, t = 4.595, P= 0.002） and IL-5 （15.65 ± 1.19vs. 12.35±0.95pg/ml, t=3.806,P=0.005） and the Bax/Bcl-2 ratio （1.51 ± 0.18 vs. 0.48 ± 0.10, t = 9.654, P 〈 0.001） and TIM-1/β-actin ratio （0.78 ± 0.11 vs. 0.40 ±0.06, t = 6.818, P 〈 0.001） in the OVA/PM group were increased compared to those in the OVA group. The concentrations of IL-4 （77.44 ± 11.19 vs. 41.47 ± 3.40 pg/ml, t = 5.617, P= 0.001） and IL-5 （ 15.65±1. 19 vs. 10.99 ± 1.40 pg/ml, t = 5.374, P = 0.001 ） and the Bax/Bcl-2 ratio （1.51 ±0.18 vs. 0.97 ± 0.16, t = 5.000, P = 0.001） and TIM-1/β-actin ratio （0.78 ± 0.11 vs. 0.31 ± 0.06,t = 8.545, P 〈 0.001 ） in the OVA/PM group were increased compared to those in the PM group. The concentration oflL-4 （41.47 ±3.40 vs. 25.46 ± 2.98 pg/ml, t = 2.501, P = 0.037） and the Bax/Bcl-2 ratio （0.97 ± 0.16 vs. 0.18 ± 0.03, t = 7.439, P 〈 0.001） and TIM-1/β-actin ratio （0.31 ± 0.06 vs. 0.02 ± 0.01, t = 5.109, P = 0.001） in the PM group were also higher than those in the control group. Conclusions： Exacerbated AHR associated with allergic asthma caused by PMz5 is related to increased apoptosis and TIM-1 activation. These data might provide insights into therapeutic targets for the treatment of acute exacerbations of asthma induced by PM2.5.