大气细颗粒物诱发血压升高的分子机制研究进展

高血压作为最常见的心血管疾病之一,是我国慢病防治的重中之重.大气细颗粒物(PM2.5)是多种心血管疾病的危险因素.在PMzs影响血压的机制中,氧化应激和炎症反应发挥着关键性作用.PM2.S的理化成分包括炭黑、有机物、无机离子和金属等,不同理化成分可以激发不同炎症通路,从多个途径影响血压调控.本综述总结PM2s影响血压的...     

PM2.5引发心血管疾病机制的研究现状

PM2.5也称细颗粒物,是指大气总悬浮颗粒物(TSP)中空气动力学直径≤2.5μm的粒子.它来源广泛,对人体的损害大于直径＞2.5 μm的颗粒物,因此现在对颗粒物的研究主要集中在PM2.5上.流行病学资料显示,PM2.5与心血管疾病的发病率和死亡率有关,但目前有关这方面的机制研究较少.本文总结了部分相关研究,归纳出3条可能的致病途径.     

PM_(2.5)对肾脏疾病影响研究进展

空气污染尤其是大气细颗粒物(PM2.5)的健康危害已经成为国内外研究热点。近年来,流行病学及基础研究发现PM2.5与慢性肾脏病、透析相关并发症及肾脏肿瘤密切相关,其机制与炎症反应、氧化应激及细胞毒性等有关。本文拟对PM2.5对肾脏疾病的影响研究做一综述。     

大气颗粒物对心血管系统疾病的影响及其机制的研究进展

国内外多项流行病学调查及实验研究表明,大气PM10、PM2.5暴露与心血管疾病的入院率和死亡率有关.目前认为大气颗粒物主要通过造成血管功能障碍、促进动脉粥样硬化形成、引起心律失常及氧化应激和炎性反应对心血管系统健康产生损害.其中对沙尘颗粒物与心血管系统疾病关系的研究尚不多且结论 并不一致.笔者对近年来国内外关于大气颗粒物与心血管系统疾病的关系及作用机制的研究进展做简要综述.     

大气颗粒物暴露对成人肺功能影响的研究进展

大气颗粒物(particulate matter,PM)是主要的大气污染物之一,近些年来一直是我国城市首要空气污染物,受到广泛的关注.有关大气颗粒物对儿童肺功能影响的研究和综述有大量报道.但是,有关大气颗粒物对成人肺功能影响的研究报道相对较少.笔者综述了近20年来国内外有关大气颗粒物暴露与成人肺功能关系的文献,并在此基础上对今后相关的研究方向进行了展望.     

大气细颗粒物不同组分的毒理学效应及其分子作用机制研究进展

大气细颗粒物(PM2.5)是指空气动力学直径小于或等于2.5 μm的颗粒物, 经由靶器官肺脏进入机体, 可诱发多种不良健康效应(如心血管疾病、糖尿病、呼吸系统疾病、神经退行性疾病和不良出生结局等)。PM2.5具有组成的复杂性(可溶性/非可溶性成分和生物成分等)、来源的多样性和二次转化等特性, 大量的流行病学和毒理学研究提示PM2.5的不同组成在诱发不良健康效应时所涉及的毒理学作用机制存在差异。另外, PM2.5作为载体, 还存在多组分间的混合暴露和联合效应。本文对近几年大气细颗粒物不同成分暴露所涉及的毒理学作用机制及不同组分间的联合效应进行了较为系统的阐述, 主要包含炎症反应、氧化应激、内质网应激、核因子κB(NF-κB)信号通路的激活等, 为PM2.5不同组分暴露所引发的不良健康效应的防治提供依据。     

大气细颗粒物的健康危害机制及拮抗作用研究进展

流行病学研究证实大气细颗粒物(PM2.5)与多种呼吸道疾病及心血管疾病的发病率与死亡率密切相关。PM2.5的毒性损伤机制除了与炎性损伤、氧化损伤相关外,还与多条细胞内信号通路有关,已成为研究的热点之一。生物活性物质因具有的抗氧化等活性已被应用于拮抗PM2.5毒性作用的研究中。因此,该文就PM2.5健康危害的流行病学研究及对细胞内信号通路的影响和生物活性物质对PM2.5的拮抗作用的研究进展进行综述。     

PM10和PM2.5与人类健康效应关系的研究进展

悬浮在空气中的颗粒物,按其空气动力学直径的大小,可分为PM10和PM2.5。2006年,WHO推荐用PM2.5代替PM10作为空气颗粒物浓度的指标。大气颗粒物（PM2.5）中主要包含有机碳、元素碳及碳酸盐碳。建筑扬尘、土壤尘、民用污染（燃煤）和交通污染（机动车尾气排放）为主要来源。北京、上海、西安日PM2.5和PM10日超标浓度皆较高。风速与春季和冬季的PM2.5质量浓度之间呈负相关,PM2.5质量浓度随空气相对湿度增加而增大,相对湿度与PM2.5质量浓度之间有正相关;温度与PM2.5质量浓度之间则无明显相关性。大气PM2.5浓度的升高会引起全死因疾病死亡率、心血管疾病死亡率的增加。大气PM2.5浓度的升高与心血管疾病有关。建议采取加大环境污染企业的治理力度,此外应该降低大城市汽车数量。     

空气颗粒物致心血管损害机制研究进展

越来越多的证据表明,空气污染与心血管疾病发病率和死亡率有关,尤以空气颗粒物(particulate matter,PM)的影响最为人们所关注,其致病机制亦有较多研究报道.本文将从流行病学研究、动物毒理实验及体外细胞实验综合阐述空气颗粒物暴露对心血管损害的生物学机制,包括炎症损伤、氧化应激和对凝血系统、自主神经系统及内皮功能的影响等.     

细颗粒物对免疫系统损伤研究中的基本科学问题

随着对大气颗粒物研究的深入，许多学逐渐认识到PM2.5易于富集空气中的有毒重金属、酸性氧化物、有机污染物、微生物等，对人体的健康影响更大。流行病学调查表明细颗粒物的浓度升高，会增加心血管疾病、肺功能下降，低体重出生，宫内窘迫等健康问题的发生。因此细颗粒物对人体健康的影响是不可忽视，     

Using moving total mortality counts to obtain improved estimates for the effect of air pollution on mortality

In many cities of the United States, measurements of ambient particulate matter air pollution (PM) are available only once every 6 days. Time-series studies conducted in these cities that investigate the relationship between mortality and PM are restricted to using a single day's PM as the measure of PM exposure. This is undesirable because current evidence suggests that the effects of PM on mortality are spread over multiple days. And studies have shown that using a single day's PM as the measure of PM exposure can result in estimates that have a large negative bias. In this article, I introduce a new model for estimating the mortality effects of PM when only every-sixth-day PM data are available. This new model uses information available in the daily mortality time series to infer otherwise lost information about the effect of PM on mortality over a period of more than a single day. This new model typically offers an increase in both statistical estimation precision and accuracy compared with existing models.     

Common household activities are associated with elevated particulate matter concentrations in bedrooms of inner-city Baltimore pre-school children

Asthma disproportionately affects inner-city, minority children in the U.S. Outdoor pollutant concentrations, including particulate matter (PM), are higher in inner-cities and contribute to childhood asthma morbidity. Although children spend the majority of time indoors, indoor PM exposures have been less extensively characterized. There is a public health imperative to characterize indoor sources of PM within this vulnerable population to enable effective intervention strategies. In the present study, we sought to identify determinants of indoor PM in homes of Baltimore inner-city pre-school children. Children ages 2-6 (n=300) who were predominantly African-American (90%) and from lower socioeconomic backgrounds were enrolled. Integrated PM(2.5) and PM(10) air sampling was conducted over a 3-day period in the children's bedrooms and at a central monitoring site while caregivers completed daily activity diaries. Homes of pre-school children in inner-city Baltimore had indoor PM concentrations that were twice as high as simultaneous outdoor concentrations. The mean indoor PM(2.5) and PM(10) concentrations were 39.5+/-34.5 and 56.2+/-44.8 microg/m(3), compared to the simultaneously measured ambient PM(2.5) and PM(10) (15.6+/-6.9 and 21.8+/-9.53 microg/m(3), respectively). Common modifiable household activities, especially smoking and sweeping, contributed significantly to higher indoor PM, as did ambient PM concentrations. Open windows were associated with significantly lower indoor PM. Further investigation of the health effects of indoor PM exposure is warranted, as are studies to evaluate the efficacy of PM reduction strategies on asthma health of inner-city children.     

Airborne fine particles pollution and health risks estimates

In this paper the results of the analyses of health risks associated with PM10 and PM2.5 are discussed, which have been made by the WHO and by a recent Italian multicentric epidemiological study in 8 cities. The distribution of PM10 and PM2.5 levels in the various cities are also considered. WHO estimates of short-term relative risk of daily mortality were 1.0074 and 1.015, by 10 microg/m3 increase respectively of PM10 and of PM2.5. Long-term risk estimates of mortality for the same increase of PM10 and PM2.5 were respectively 1.10 and 1.14, whereas more recent evaluations have indicated a value of 1.07 for PM2.5. The Italian meta-analysis study was concentrated on short-term effects associated to PM10. The effect estimate on mortality was an increase of 1.17%. The short-term effects indicated by the Italian study appeared greater than those estimated by WHO, but the confidence intervals (0.44%-2.06%) included the value of 0.74%. The hypothesis of a greater risk in Italy for the same increase of PM10 deserves further examination. The available mean concentration levels of PM10 in Italy showed an acceptable agreement, even if they were produced by different bodies. Mean yearly concentration of PM10 in the major Italian cities resulted about 50 microg/m3, range 30 microg/m3 to less than 70 microg/m3 since the first '90 up to 2001. Very few data are available on PM2.5, with the exception of Rome where mean annual levels resulted near 28 microg/m3, with 24 h averages ranging from 5 to 101 microg/m3.     

Impact of the time of outpatient monitoring of patients with implanted pacemakers to evaluate dangerous changes in the parameters of apparatuses

Patients with implanted pacemakers (PM) should pass outpatient monitoring at definite intervals given in the PM certificate. The paper shows that the monitoring periods in the patients are frequently violated, therefore the voltage of the PM battery is less than the critical level at which the PM is to be replaced. As the discharge of the battery is less than the critical level, the electronic unit of the PM begins first to regenerate an irregular sequence of stimulating pulses and then the generation of pulses stops. Thus, if the outpatient monitoring intervals in patients with implanted PM are over those given in the PM certificate, this will cause errors in encoding the causes of replacement of a PM, followed by dangerous changes in its parameters.     

Assessment of personal and community-level exposures to particulate matter among children with asthma in Detroit, Michigan, as part of Community Action Against Asthma (CAAA)

We report on the research conducted by the Community Action Against Asthma (CAAA) in Detroit, Michigan, to evaluate personal and community-level exposures to particulate matter (PM) among children with asthma living in an urban environment. CAAA is a community-based participatory research collaboration among academia, health agencies, and community-based organizations. CAAA investigates the effects of environmental exposures on the residents of Detroit through a participatory process that engages participants from the affected communities in all aspects of the design and conduct of the research; disseminates the results to all parties involved; and uses the research results to design, in collaboration with all partners, interventions to reduce the identified environmental exposures. The CAAA PM exposure assessment includes four seasonal measurement campaigns each year that are conducted for a 2-week duration each season. In each seasonal measurement period, daily ambient measurements of PM2.5 and PM10 (particulate matter with a mass median aerodynamic diameter less than 2.5 microm and 10 microm, respectively) are collected at two elementary schools in the eastside and southwest communities of Detroit. Concurrently, indoor measurements of PM2.5 and PM10 are made at the schools as well as inside the homes of a subset of 20 children with asthma. Daily personal exposure measurements of PM10 are also collected for these 20 children with asthma. Results from the first five seasonal assessment periods reveal that mean personal PM10 (68.4 39.2 microg/m(3)) and indoor home PM10 (52.2 30.6 microg/m(3)) exposures are significantly greater (p < 0.05) than the outdoor PM10 concentrations (25.8 11.8 microg/m(3)). The same was also found for PM2.5 (indoor PM2.5 = 34.4 21.7 microg/m(3); outdoor PM2.5 = 15.6 8.2 microg/m(3)). In addition, significant differences (p < 0.05) in community-level exposure to both PM10 and PM2.5 are observed between the two Detroit communities (southwest PM10 = 28.9 14.4 microg/m(3)), PM2.5 = 17.0 9.3 microg/m(3); eastside PM10 = 23.8 12.1 microg/m(3), PM2.5 = 15.5 9.0 microg/m(3). The increased levels in the southwest Detroit community are likely due to the proximity to heavy industrial pollutant point sources and interstate motorways. Trace element characterization of filter samples collected over the 2-year period will allow a more complete assessment of the PM components. When combined with other project measures, including concurrent seasonal twice-daily peak expiratory flow and forced expiratory volume at 1 sec and daily asthma symptom and medication dairies for 300 children with asthma living in the two Detroit communities, these data will allow not only investigations into the sources of PM in the Detroit airshed with regard to PM exposure assessment but also the role of air pollutants in exacerbation of childhood asthma.     

室内空气PM2.5研究现状及发展趋势

PM25由于其较小的粒径、巨大的比表面积、较大的危害性等独有的特点而受到国际的广泛关注。该文简述了室内空气中PM25的暴露水平的研究，论述了PM25的物理化学性质、流行病学和毒理学特征研究进展，分析了室内PM25来源及影响室内PM25的控制因素，并提出了PM25的发展趋势。PM25的形成方式有两种：一种是直接以固态形式排出的一次粒子，另一种是由气态化学反应而生成的二次粒子。     

A regression approach for estimating multiday adverse health effects of PM10 when daily PM10 data are unavailable

The authors propose a regression-based approach for obtaining multiday estimates of the adverse health effects of ambient particulate matter less than 10 microm in diameter (PM(10)) when daily PM(10) time-series data are unavailable. This situation is common in the United States, because most US cities take PM(10) measurements every 6 days. Current evidence suggests that adverse effects of PM(10) are not concentrated on a single day but rather are spread out over multiple days, so the unavailability of daily PM(10) data presents a problem for the estimation of these effects. The proposed model estimates weights that are used to construct a linear combination of single-lag PM(10) effect estimates obtained from the available PM(10) data. It is shown that this new approach provides estimates of the effect of PM(10) on mortality that have less bias and mean squared error than currently available methods. Application of this method to the US cities contained in the National Morbidity, Mortality, and Air Pollution Study database produces an estimated national average effect of PM(10) on nonaccidental mortality in persons over age 65 years, corresponding to a 0.32% increase per 10-microg/m(3) increment in PM(10). The estimated effects for cardiorespiratory mortality and other mortality are 0.34% and 0.22%, respectively.     

Incorporating exposure models in probabilistic assessment of the risks of premature mortality from particulate matter

This paper examines the link between the ambient level of particulate pollution and subsequent human health effects and various sources of uncertainty when total exposure is taken into consideration. The exposure simulation model statistically simulates daily personal total exposure to ambient PM and nonambient PM generated from indoor sources. It incorporates outdoor-indoor penetration of PM, contributions of PM from indoor sources, and time-activity patterns for target groups of the population. The model is illustrated for Los Angeles County using recent 1997 monitoring data for both PM(10) and PM(2.5). The results indicate that, on average, outdoor-source PM contributes about 20-25% of the total PM exposure to Los Angeles County individuals not exposed to environmental tobacco smoking (ETS), and about 15% for those who are exposed to ETS. The model computes both the fractional contribution of outdoor concentrations to total exposure and the effect of exposure uncertainties on the estimated slope of the (linear) concentration-response curve in time-series studies for PM health effects. The latter considers the effects of measurement and misclassification error on PM epidemiological time-series studies. The paper compares the predictions of a conventional PM epidemiological model, based solely on ambient concentration measurements at a central monitoring station, and an exposure simulation model, which considers the quantitative relationship between central-monitoring PM concentrations and total individual exposures to particulate matter. The results show that the effects of adjusting from outdoor concentrations to personal exposures and correcting dose-response bias are nearly equal, so that roughly the same premature mortalities associated with short-term exposure to both ambient PM(2.5) and PM(10) in Los Angeles County are predicted with both models. The uncertainty in the slope of the concentration-response curve in the time-series studies is the single most important source of uncertainty in both the ambient- and the exposure-health model.     

Health effects of particles in ambient air

A summary of a critical review by a working group of the German commission on Air Pollution Prevention of VDI and DIN of the actual data on exposure and health effects (excluding cancer) of fine particulate air pollution is presented. EXPOSURE: Typical ambient particle concentrations for PM10 (PM2.5) in Germany are in the range of 10-45 (10-30) microg/m3 as annual mean and 50-200 (40-150) microg/m3 as maximum daily mean. The ratio of PM2.5/PM10 generally amounts between 0.7 and 0.9. HEALTH EFFECTS: During the past 10 years many new epidemiological and toxicological studies on health effects of particulate matter (PM) have been published. In summary, long-term exposure against PM for years or decades is associated with elevated total, cardiovascular, and infant mortality. With respect to morbidity, respiratory symptoms, lung growth, and function of the immune system are affected. Short-term studies show consistant associations of exposure to daily concentrations of PM with mortality and morbidity on the same day or the subsequent days. Patients with asthma, COPD, pneumonia, and other respiratory diseases as well as patients with cardio-vascular diseases and diabetes are especially affected. The strongest associations are found for PM2.5 followed by PM10, with no indication of a threshold value for the health effects. The data base for ultra fine particles is too small for final conclusions. The available toxicological data support the epidemiological findings and give hints as to the mechanisms of the effects. CONCLUSION: The working group concludes that a further reduction of the limit values proposed for 2005 will substantially reduce health risks due to particulate air pollution. Because of the strong correlation of PM10 with PM2.5 at most German sites there is no specific need for limit values of PM2.5 for Germany in addition to those of PM10.