室内颗粒物污染对儿童哮喘的影响

目的探讨室内大气PM_(10)、PM_(2.5)、PM1污染对儿童哮喘的影响。方法采用1∶1成组病例-对照研究,于2015年10月—2016年5月对石河子市80名哮喘儿童和80名健康对照儿童进行问卷调查与室内颗粒物浓度检测,分析儿童哮喘的危险因素。结果两组合计160名儿童的室内PM_(10)、PM_(2.5)、PM1浓度范围分别为26.57~507.30、12.66~159.00、4.53~77.08μg/m~3,其中PM_(10)超标率为61.9%,PM_(2.5)超标率为6.9%。病例组室内空气中的PM_(10)、PM_(2.5)、PM1浓度中位数均高于对照组,差异有统计学意义(P0.01)。多因素logistic回归分析结果显示,儿童有过敏史(OR=5.171)、有环境烟草烟雾(ETS)暴露(OR=2.429)、PM_(2.5)浓度高于中位数(OR=3.459)是儿童哮喘的危险因素,母乳喂养(OR=0.454)是儿童哮喘的保护因素,均有统计学意义(P0.05)。结论儿童有过敏史、ETS暴露和PM_(2.5)暴露可能增加儿童哮喘风险,同时应提倡母乳喂养,以保护儿童呼吸系统健康。     

成都市重污染天气对高新区儿童上呼吸道健康的影响

目的探讨重污染天气对儿童上呼吸道健康的危害。方法 2015-2017年采用分层整群抽样方法,连续3年抽取成都高新区1所小学3～5年级儿童(每年不少于600人)作为调查对象。在重污染天气期间和非重污染天气进行上呼吸道症状监测,并调查大气污染状况。以重污染天气期间污染物最低浓度组的症状发生率OR值为1,计算其他浓度组症状发生率的OR值。结果 2015-2017年重污染天气期间上呼吸道日均症状发生率(3.5%～13.4%)均高于同年非重污染天气(0.9%～2.5%)(P0.01)。2015年重污染天气期间NO_2、SO_2、PM_(10)和PM2.5平均浓度较非重污染天气分别高出24.7μg/m~3、15.6μg/m~3、133.9μg/m~3、95.3μg/m~3(P0.01),儿童上呼吸道症状发生率与NO_2和SO_2浓度成正相关关系。当NO_2浓度达到69～72μg/m~3时,咽喉症状发生率OR值为3.44,83～90μg/m~3时鼻腔状发生率OR值为3.16;SO_2浓度达到30～35μg/m~3时,咽喉和鼻腔症状发生率OR值分别为2.40和2.12;PM_(10)浓度达到181～224μg/m~3时,咽喉及鼻腔症状发生率OR值分别为2.16和1.86;PM2.5浓度达到120～150μg/m~3时,咽喉及鼻腔症状发生率OR值分别为2.19和1.96。除NO_2对鼻腔症状发生率的影响基本呈升高趋势,其他污染物从低浓度开始上升到某一浓度时,上呼吸道症状发生率随之升高并达到最大,浓度进一步升高时症状发生率有起伏的降低,但仍保持在较高水平。结论重污染天气是影响儿童上呼吸道健康的危险因素,随着污染物浓度的增加,儿童上呼吸道症状发生率也明显升高,但儿童对不同污染物的易感性有个体差异,当浓度达到某一个水平时症状发生率不再继续升高。     

不同类型公共场所室内空气PM_(2.5)浓度及影响因素

目的了解不同类型公共场所室内PM_(2.5)污染情况,探讨室内外PM_(2.5)关系及影响室内PM_(2.5)浓度的因素。方法于2015年7—8月和11—12月以南京市4类32家公共场所[商场(超市)、影院、餐厅、医院]为研究对象,采用重量法同时测定室内外PM_(2.5)浓度,使用温湿度计实时记录室内外温湿度,通过调查问卷收集采样期间室内人员吸烟、门窗开关、新风系统使用等信息,利用多重线性回归分析室内PM_(2.5)浓度的影响因素。结果夏季室内外PM_(2.5)浓度中位数分别为44μg/m~3(范围:13~158μg/m~3)和36μg/m~3(范围:20~71μg/m~3),均显著低于冬季值[117μg/m~3(范围:39~341μg/m~3)和100μg/m~3(范围:53~229μg/m~3)]。在夏季,餐厅的室内PM_(2.5)浓度显著高于影院和商场(超市)(P0.05),全部调查对象室内外PM_(2.5)浓度比值(I/O值)中位数为1.1(范围:0.39~5.12),其中餐厅、商场(超市)、医院和影院I/O值大于1的比例分别为90%(9/10)、40%(4/10)、80%(4/5)和0%(0/5)。但冬季不同类型公共场所室内PM_(2.5)浓度差异无统计学意义(P0.05);全部调查对象I/O值中位数为0.92(范围:0.59~1.89),显著低于夏季(P=0.029),其中餐厅、商场(超市)、医院和影院I/O值大于1的比例分别为60%(6/10)、40%(4/10)、40%(2/5)和0%(0/5)。多重线性回归分析结果显示,影响夏季公共场所室内PM_(2.5)浓度主要因素为室内人员吸烟(β=0.548,P0.001)和新风系统使用(β=-0.513,P0.001),回归方程的决定系数(R~2)为0.420,而影响冬季室内PM_(2.5)浓度的主要因素为室外PM_(2.5)浓度(β=0.984,P0.001)和室内外相对湿度差的绝对值(β=-0.027,P0.001),回归方程的决定系数(R~2)为0.814。结论南京市典型公共场所室内PM_(2.5)污染状况和室内外PM_(2.5)浓度关系均存在季节性差别,室外PM_(2.5)浓度、室内人员吸烟、新风系统使用和通风换气等是影响室内PM_(2.5)浓度重要因素。     

福建省2019年公共场所室内外空气PM_(10)与PM_(2.5)浓度及对从业人员的健康影响

目的监测福建省4类公共场所空气颗粒物(PM_(10)、PM_(2.5))室内外浓度,了解从业人员健康状况,探讨颗粒物对人群的健康影响。方法采用横断面调查法,对福建省4个设区市的168家公共场所(含宾馆/酒店、理发店、美发店及候车室4类场所)的环境进行现场检测,调查从业人员1 651人,计算症状/体征自报率并分析影响因素。结果从业人员眼睛、呼吸系统及皮肤的症状/体征自报率分别为40.4%(667人)、42.1%(695人)及24.7%(408人);现场环境检测中,PM_(10)、PM_(2.5)室内浓度中位数分别为67μg/m~3、36μg/m~3,室外分别为70μg/m~3、38μg/m~3,浓度差中位数分别为0(23～521)μg/m~3、-1(11～236)μg/m~3,PM_(10)浓度室内大于室外,PM_(2.5)室外大于室内(Zc=4.68、3.40,P均0.01);从业人员健康影响因素logistic回归分析显示,男性、工龄5～9年及文化程度小学危险度相对较低;饮酒及高PM_(10)、PM_(2.5)浓度是健康的危险因素。结论颗粒物对人体健康影响的非特异性,可能导致环境污染物对人群健康的影响被低估,应加强公共场所环境管理,以保护从业人员健康。     

北京市昌平区大气颗粒物中多环芳烃暴露及人群健康风险评价

目的了解北京市昌平区大气颗粒物PM_(10)、PM_(2.5)及多环芳烃(PAHs)的污染水平,分析PAHs的污染来源,并进行人群健康风险评估。方法于2015年1—12月用大气采样器采集北京市昌平区大气样品,分别用称重法和高效液相色谱法检测大气PM_(10)、PM_(2.5)质量浓度和16种PAHs浓度;利用比值法分析PAHs的污染来源,并对其人群健康风险进行评估。结果 2015年北京市昌平区大气PM_(10)和PM_(2.5)的质量浓度范围分别为7.8~343.0μg/m~3和6.3~344.3μg/m~3,年均浓度分别为97.0、78.6μg/m~3;PAHs浓度范围为2.4~383.0 ng/m~3,年均浓度为87.8 ng/m~3。4环PAHs浓度与5、6环PAHs浓度比值范围为0.15~1.38。PAHs的等效毒性浓度以夏季最低(0.354 ng/m~3),冬季最高(29.816 ng/m3)。PAHs对成人及儿童的终身致癌超额风险分别为9.68×10~(-6)和6.14×10~(-6)。结论北京市昌平区大气颗粒物浓度高于GB 3095—2012《环境空气质量标准》二级标准,PAHs污染主要来自本地污染;PAHs对成人的终身致癌风险高于儿童,但两者均处于可接受水平。     

妊娠窗口期大气颗粒物暴露对早产影响的meta分析

目的综合以往发表的相关文献,分析不同妊娠窗口期大气颗粒物(PM_(2.5)、PM_(10))暴露对早产的影响。方法检索国内外2000年1月1日—2015年10月1日公开发表的关于大气颗粒物暴露对早产影响的研究文献,根据纳入及排除标准筛选出符合要求的文献26篇,采用R 3.1.1软件的metafor统计包对入选文献进行异质性检验和相应的效应值合并,并对结果进行敏感性分析、发表偏倚检验和校正,评价妊娠窗口期颗粒物暴露对早产的影响。结果通过建立各妊娠窗口期大气颗粒物与早产的暴露-反应关系,发现大气PM_(2.5)浓度每升高10μg/m~3,妊娠早、中、晚期及整个妊娠期早产发生的合并OR(95%CI)分别为1.10(1.01~1.21),1.07(0.79~1.45),1.04(0.97~1.10),1.05(0.97~1.13);大气PM10浓度每升高10μg/m~3,妊娠早、中、晚期及整个妊娠期早产发生的合并OR(95%CI)分别为0.98(0.97~1.00),0.99(0.98~1.01),1.01(0.99~1.04)和1.00(1.00~1.00)。结论不同妊娠窗口期的大气颗粒物暴露所致早产发生风险存在差异,妊娠早期大气PM_(2.5)的暴露可明显增加早产风险。     

火车站室内空气PM_(10)及PM_(2.5)污染调查

为探讨火车站室内环境质量,于2017年2月对长江三角洲地区6个火车站(4个新建火车站、2个旧式火车站)内不同位置PM_(10)及PM_(2.5)浓度进行检测。结果显示,新建火车站室内PM_(10)的浓度范围为98.5～220.4μg/m~3,PM_(2.5)的浓度范围为46.0～84.6μg/m~3;楼梯和电梯附近采样点设有排气扇,大气颗粒物浓度最低;所测6个车站的室内外颗粒物浓度比值(I/O)均小于1。提示新建火车站空气质量优于旧式火车站,通风设备有利于减弱PM_(10)及PM_(2.5)浓度,且室内空气质量优于室外。     

青岛市大气污染物对心脑血管疾病住院影响的病例交叉研究

目的探讨青岛市大气污染对心脑血管疾病住院的急性影响。方法采用时间分层的病例交叉设计,分析青岛市2014—2016年大气污染物(PM_(2.5)、SO_2、NO_2)浓度短期升高对人群心脑血管疾病急性住院的影响。结果在控制同期气象因素后,在单污染物模型中,大气PM2.5浓度每升高10μg/m~3,心、脑血管疾病住院增加,该影响均表现为当日效应,住院当日OR值达到最高,分别为1.011(95%CI:1.010~1.012)和1.010(95%CI:1.009~1.012);大气SO_2浓度每升高10μg/m~3,心、脑血管疾病住院增加,该影响均表现为当日效应,住院当日OR值分别为1.095(95%CI:1.089~1.100)和1.102(95%CI:1.096~1.109);大气NO_2浓度每升高10μg/m~3,心血管疾病住院增加,该影响表现为当日效应,OR值为1.060(95%CI:1.056~1.064),滞后3 d(lag3)的脑血管疾病住院的OR值最高,为1.064(95%CI:1.060~1.068)。在多污染物模型中,PM_(2.5)、SO_2及NO_2浓度每升高10μg/m~3对心脑血管疾病住院的OR值均有统计学意义(P0.01),且OR值高于单污染物模型。在性别和年龄的分层分析中,PM_(2.5)和SO_2浓度增加对脑血管疾病住院的影响表现为女性高于男性;SO_2浓度增加对65岁以下人群心血管疾病住院的影响较高,NO_2对脑血管疾病住院的影响表现为65岁及以上人群较高,差异均有统计学意义(P0.05)。结论目前青岛市大气污染物对人群健康有短期影响,能增加心脑血管疾病住院人数。     

冬季学生宿舍室内PM_(2.5)浓度及通风的影响

为探讨开关窗通风对宿舍室内PM_(2.5)浓度的影响。于2015年11—12月选取某高校31个有代表性的学生宿舍,使用颗粒物检测仪进行PM_(2.5)浓度的检测。观察关窗密闭、开窗通风和通风后密闭对宿舍室内PM_(2.5)浓度的影响。结果显示通风前密闭状态下PM_(2.5)平均浓度为176.28μg/m~3,通风状态下为183.72μg/m~3,通风后密闭状态下为176.28μg/m~3,室外为187.00μg/m~3。通风状态和通风前后密闭状态的宿舍室内PM_(2.5)浓度差异有统计学意义(P0.05);无论通风与否,室内外PM_(2.5)浓度具有高度相关性(rs0.854 8,P0.000 1)。提示室外PM_(2.5)直接影响宿舍室内PM_(2.5)的浓度,关窗并不能有效降低室内PM_(2.5)的浓度,开窗后密闭可降低通风后室内PM_(2.5)的浓度。     

马鞍山市公共场所室内PM_(2.5)污染状况分析

目的了解马鞍山市部分公共场所室内PM_(2.5)的污染水平,探讨其可能的影响因素。方法于2013年1月至2014年3月,以马鞍山市25家公共场所(宾馆、洗浴中心、网吧、咖啡馆、电影院各5家)作为监测对象,采用光散射法测定室内外PM_(2.5)浓度,同时现场记录监测点的室内人员数量、吸烟人员数量、禁烟政策、空调使用情况等。结果公共场所室内PM_(2.5)浓度的中位数(M)为104μg/m~3,四分位数间距(IQR)为63~194μg/m~3。不同类型公共场所的室内PM_(2.5)浓度差异有统计学意义(F=31.569,P0.001)。网吧室内PM_(2.5)浓度最高,M(IQR)为289(222~609)μg/m~3,咖啡馆次之,为203(110~335)μg/m~3,宾馆、洗浴中心和电影院最低,分别为98(50~142)、88(59~157)、75(53~102)μg/m~3。多重线性回归分析显示,室内PM_(2.5)浓度随着室外PM_(2.5)浓度、室内吸烟人时密度及室内人时密度的增加而升高,不使用地毯、使用中央空调、实施禁烟政策和使用机械通风均可降低室内PM_(2.5)浓度,差异均有统计学意义(P0.05)。结论调查期间马鞍山市公共场所室内PM_(2.5)污染较严重。室外PM_(2.5)、室内吸烟、室内人员、地毯等是室内PM_(2.5)的污染来源。     

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.     

Home indoor pollutant exposures among inner-city children with and without asthma

BACKGROUND: Evidence for environmental causes of asthma is limited, especially among African Americans. To look for systematic differences in early life domestic exposures between inner-city preschool children with and without asthma, we performed a study of home indoor air pollutants and allergens. METHODS: Children 2-6 years of age were enrolled in a cohort study in East Baltimore, Maryland. From the child's bedroom, air was monitored for 3 days for particulate matter 0.05]. Settled dust allergen levels (cat, dust mite, cockroach, dog, and mouse) were also similar in bedrooms of asthmatic and control children. CONCLUSIONS: Exposures to common home indoor pollutants and allergens are similar for inner-city preschool children with and without asthma. Although these exposures may exacerbate existing asthma, this study does not support a causative role of these factors for risk of developing childhood asthma.     

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.     

Exposure assessment of particulate matter for susceptible populations in Seattle

In this article we present results from a 2-year comprehensive exposure assessment study that examined the particulate matter (PM) exposures and health effects in 108 individuals with and without chronic obstructive pulmonary disease (COPD), coronary heart disease (CHD), and asthma. The average personal exposures to PM with aerodynamic diameters < 2.5 microm (PM2.5) were similar to the average outdoor PM2.5 concentrations but significantly higher than the average indoor concentrations. Personal PM2.5 exposures in our study groups were lower than those reported in other panel studies of susceptible populations. Indoor and outdoor PM2.5, PM10 (PM with aerodynamic diameters < 10 microm), and the ratio of PM2.5 to PM10 were significantly higher during the heating season. The increase in outdoor PM10 in winter was primarily due to an increase in the PM2.5 fraction. A similar seasonal variation was found for personal PM2.5. The high-risk subjects in our study engaged in an equal amount of dust-generating activities compared with the healthy elderly subjects. The children in the study experienced the highest indoor PM2.5 and PM10 concentrations. Personal PM2.5 exposures varied by study group, with elderly healthy and CHD subjects having the lowest exposures and asthmatic children having the highest exposures. Within study groups, the PM2.5 exposure varied depending on residence because of different particle infiltration efficiencies. Although we found a wide range of longitudinal correlations between central-site and personal PM2.5 measurements, the longitudinal r is closely related to the particle infiltration efficiency. PM2.5 exposures among the COPD and CHD subjects can be predicted with relatively good power with a microenvironmental model composed of three microenvironments. The prediction power is the lowest for the asthmatic children.     

An association between fine particles and asthma emergency department visits for children in Seattle.

Asthma is the most common chronic illness of childhood and its prevalence is increasing, causing much concern for identification of risk factors such as air pollution. We previously conducted a study showing a relationship between asthma visits in all persons < 65 years of age to emergency departments (EDs) and air pollution in Seattle, Washington. In that study the most frequent zip codes of the visits were in the inner city. The Seattle-King County Department of Public Health (Seattle, WA) subsequently published a report which showed that the hospitalization rate for children in the inner city was over 600/100,000, whereas it was < 100/100,000 for children living in the suburbs. Therefore, we conducted the present study to evaluate whether asthma visits to hospital emergency departments in the inner city of Seattle were associated with outdoor air pollution levels. ED visits to six hospitals for asthma and daily air pollution data were obtained for 15 months during 1995 and 1996. The association between air pollution and childhood ED visits for asthma from the inner city area with high asthma hospitalization rates were compared with those from lower hospital utilization areas. Daily ED counts were regressed against fine particulate matter (PM), carbon monoxide (CO), sulfur dioxide, and nitrogen dioxide using a semiparametric Poisson regression model. Significant associations were found between ED visits for asthma in children and fine PM and CO. A change of 11 microg/m3 in fine PM was associated with a relative rate of 1.15 [95% confidence interval (CI), 1.08-1.23]. There was no stronger association between ED visits for asthma and air pollution in the higher hospital utilization area than in the lower utilization area. These findings were seen when estimated PM2.5 concentrations were below the newly adopted annual National Ambient Air Quality Standard of 15 microg/m3.     

Particulate matter measurements PM2.5 and PM10 in Rome: comparison indoor/outdoor

The concentration of airborne particulate matter (PM2.5 and PM10) was assessed over 12 months (1999-2000) both outdoor and indoor (workplaces and homes without major PM sources) through a manual gravimetric method. Mean concentration values outdoors were moderately lower than indoor concentrations in summer, but higher in winter. The correlations between outdoor and indoor values are statistically significant, especially for PM2.5 in winter. The position of indoor sites with respect to street level was immaterial as far as mean values is concerned, whilst maximum values presented some differences accordingly. Day-to-day variability was higher outside than inside, especially in winter. The PM2.5/PM10 ratio was higher indoors, probably owing to the higher sedimentation speed of the coarse fraction.     

High prevalence of childhood asthma in Northern Israel is linked to air pollution by particulate matter: evidence from GIS analysis and Bayesian Model Averaging

The medical records of 3922 school children residing in the Greater Haifa Metropolitan Area in Northern Israel were analyzed. Individual exposure to ambient air pollution (SO(2) and PM(10)) for each child was estimated using Geographic Information Systems tools. Factors affecting childhood asthma risk were then investigated using logistic regression and the more recently developed Bayesian Model Averaging (BMA) tools. The analysis reveals that childhood asthma in the study area appears to be significantly associated with particulate matter of less than 10 μm in aerodynamic diameter (PM(10)) (Odds Ratio (OR) = .11; P<0.001). However, no significant association with asthma prevalence was found for SO(2) (P >0.2), when PM(10) and SO(2) were introduced into the models simultaneously. When considering a change in PM(10) between the least and the most polluted parts of the study area (9.4 μg/m(3)), the corresponding OR, calculated using the BMA analysis, is 2.58 (with 95% posterior probability limits of OR ranging from 1.52 to 4.41), controlled for gender, age, proximity to main roads, the town of a child's residence, and family's socio-economic status. Thus, it is concluded that exposure to airborne particular matter, even at relatively low concentrations (40-50 μg/m(3)), generally below international air pollution standards (55-70 μg/m(3)), appears to be a considerable risk factor for childhood asthma in urban areas. This should be a cause of concern for public health authorities and environmental decision-makers.     

Relationships among personal, indoor, and outdoor fine and coarse particle concentrations for individuals with COPD

This study characterizes the personal, indoor, and outdoor PM2.5, PM10, and PM2.5-10 exposures of 18 individuals with chronic obstructive pulmonary disease (COPD) living in Boston, MA. Monitoring was performed for each participant for six consecutive days in the winters of 1996 or 1997 and for six to twelve days in the summer of 1996. On each day, 12-h personal, indoor, and outdoor samples of PM2.5 and PM10 were collected simultaneously. Home characteristic information and time-activity patterns were also obtained. Personal exposures were higher than corresponding indoor and outdoor concentrations for all particle measures and for all seasons, except for winter indoor PM2.5-10 levels, which were higher than personal and outdoor levels. Higher personal exposures may be due to the proximity of the individuals to particle sources, such as cooking and cleaning. Indoor concentrations were associated with both outdoor concentrations and personal exposures (as determined by individual least square regression analyses), with associations strongest for PM2.5. Indoor PM2.5 concentrations were significantly associated with outdoor and personal levels for 12 and 15 of the 17 individuals, respectively. Both the strength and magnitude of the associations varied by individual. Also, personal PM2.5, but not PM2.5-10, exposures were associated with outdoor levels, with 10 of the 17 subjects having significant associations. The strength of the personal-outdoor association for PM2.5 was strongly related to that for indoor and outdoor levels, suggesting that home characteristics and indoor particulate sources were key determinants of the personal-outdoor association for PM2.5. Air exchange rates were found to be important determinants of both indoor and personal levels. Again, substantial interpersonal variability in the personal-outdoor relationship was found, as personal exposures varied by as much as 200% for a given outdoor level.     

Indoor exposures to air pollutants and allergens in the homes of asthmatic children in inner-city Baltimore

This paper presents indoor air pollutant concentrations and allergen levels collected from the homes of 100 Baltimore city asthmatic children participating in an asthma intervention trial. Particulate matter (PM), NO2, and O3 samples were collected over 72 h in the child's sleeping room. Time-resolved PM was also assessed using a portable direct-reading nephelometer. Dust allergen samples were collected from the child's bedroom, the family room, and the kitchen. The mean PM10 concentration, 56.5+/-40.7 microg/m3, is 25% higher than the PM2.5 concentration (N=90), 45.1+/-37.5 microg/m3. PM concentrations measured using a nephelometer are consistent and highly correlated with gravimetric estimates. Smoking households' average PM2.5 and PM10 concentrations are 33-54 microg/m3 greater than those of nonsmoking houses, with each cigarette smoked adding 1.0 microm/m3 to indoor PM2.5 and PM10 concentrations. Large percentages of NO2 and O3 samples, 25% and 75%, respectively, were below the limit of detection. The mean NO2 indoor concentration is 31.6+/-40.2 ppb, while the mean indoor O3 concentration in the ozone season was 3.3+/-7.7 ppb. The levels of allergens are similar to those found in other inner cities. Results presented in this paper indicate that asthmatic children in Baltimore are exposed to elevated allergens and indoor air pollutants. Understanding this combined insult may help to explain the differential asthma burden between inner-city and non-inner-city children.