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Biomedical subjects

J D Spengler

Publications and source records attributed to J D Spengler.

At least 91 records · Page 5Linked to original sources
PubMed1987

Health effects and sources of indoor air pollution. Part I.

Since the early 1970s, the health effects of indoor air pollution have been investigated with increasing intensity. Consequently, a large body of literature is now available on diverse aspects of indoor air pollution: sources, concentrations, health effects, engineering, and policy. This review begins with a review of the principal pollutants found in indoor environments and their sources. Subsequently, exposure to indoor air pollutants and health effects are considered, with an emphasis on those indoor air quality problems of greatest concern at present: passive exposure to tobacco smoke, nitrogen dioxide from gas-fueled cooking stoves, formaldehyde exposure, radon daughter exposure, and the diverse health problems encountered by workers in newer sealed office buildings. The review concludes by briefly addressing assessment of indoor air quality, control technology, research needs, and clinical implications.

Air Pollutants↗
PubMed1986

Effects of ambient sulfur oxides and suspended particles on respiratory health of preadolescent children.

Reported here are the results from an ongoing study of outdoor air pollution and respiratory health of children living in six cities in the eastern and midwestern United States. The study enrolled 10,106 white preadolescent children between 1974 and 1977 in 3 successive annual visits to each city. Each child received a spirometric examination, and a parent completed a standard questionnaire. Of this cohort, 8,380 children were seen for a second examination 1 yr later. An air pollution monitoring program was begun in each community at about the time of the first examination. For this report, measurements of total suspended particulates (TSP), the sulfate fraction of TSP (TSO4), and sulfur dioxide (SO2) concentrations at study-affiliated outdoor stations were combined with measurements at other public and private monitoring sites to create a record of TSP, TSO4, and SO2 concentrations in each of 9 air pollution regions during the 1-yr period preceding each examination and, for TSP, during each child's lifetime up to the time of testing. Across the 6 cities, frequency of cough was significantly associated with the average of 24-h mean concentrations of all 3 air pollutants during the year preceding the health examination (p less than 0.01). Rates of bronchitis and a composite measure of lower respiratory illness were significantly associated with average particulate concentrations (p less than 0.05). In analyses restricted to lifetime residents, these outcomes were significantly associated with measures of lifetime mean TSP concentration. Within the cities, however, temporal and spatial variation in air pollutant concentrations and illness and symptom rates were not positively associated.(ABSTRACT TRUNCATED AT 250 WORDS)

Air Pollutants↗
PubMed1985

Analysis of health effects resulting from population exposures to acid precipitation precursors.

Types of available studies relevant to the quantification of air pollution health effects and their principal limitations are discussed. Assessments are provided based on review and re-analysis of previously reported data bases, synthesis of published findings, and original analysis of health data sets using new methods or recent size-specific particle mass measurements. Interim results from ongoing research activities on airborne particle health effects are presented. It is shown that preliminary results obtained from cross-sectional and time-series mortality studies appear to be consistent, indicating that particulate air pollution, even at current levels, could be of concern for public health. Throughout the paper, methodological deficiencies and remaining gaps in knowledge are identified. In particular, uncertainties associated with the reported exposure-response coefficients are assessed. Finally, by characterizing the limitations of analysis we propose various recommendations for future studies and research that will serve to further define the nature, magnitude, and uncertainties of air pollution health risks.

Acids↗
PubMed1985

Problems in the estimation of human exposure to components of acid precipitation precursors.

Problems associated with estimation of human exposure to ambient air pollutants are discussed. Ideally, we would prefer to have some indication of actual dose. For most pollutants this is not presently feasible. Specific problems discussed are adequacy of outdoor monitors; the need to correct for exposures and time spent indoors; the need to have particle size distributions described and the chemistry of the particles presented. These indicate the need to develop lightweight accurate and reliable personal monitors.

Acids↗
PubMed1985

Indoor air pollution.

Although official efforts to control air pollution have traditionally focused on outdoor air, it is now apparent that elevated contaminant concentrations are common inside some private and public buildings. Concerns about potential public health problems due to indoor air pollution are based on evidence that urban residents typically spend more than 90 percent of their time indoors, concentrations of some contaminants are higher indoors than outdoors, and for some pollutants personal exposures are not characterized adequately by outdoor measurements. Among the more important indoor contaminants associated with health or irritation effects are passive tobacco smoke, radon decay products, carbon monoxide, nitrogen dioxide, formaldehyde, asbestos fibers, microorganisms and aeroallergens. Efforts to assess health risks associated with indoor air pollution are limited by insufficient information about the number of people exposed, the pattern and severity of exposures, and the health consequences of exposures. An overall strategy should be developed to investigate indoor exposures, health effects, control options, and public policy alternatives.

Air Conditioning↗
PubMed1985

Harvard Air Pollution Health Study in six cites in the U.S.A.

The Harvard Air Pollution Health Study has been a ten year prospective study of respiratory symptoms and pulmonary function of children and adults living in six U.S. communities. Indices of acute and chronic effects of air pollution exposures have been studied. Evidence is presented for adverse effects of ambient and indoor air pollution on children. Relationships between ambient TSP concentrations and hospital emergency room admissions, temporary decreases in pulmonary functions and prevalence of community bronchitis all indicate a slight adverse effect. Refinements of these relationships will occur when fine fraction and acid sulfate aerosol concentrations are incorporated into the health analysis. Exposures to cigarette smoke at home are associated with increased reported respiratory symptoms in children. There is a negative relationship between maternal smoking and age and sex adjusted height for children. Results from indoor and personal exposure studies have lead to the design of an acute symptoms and indoor air pollution study. Between 1985 and 1988 1800 children will be tracked for a year while respirable particles, nitrogen dioxide, water vapor and air exchange will be measured in their homes. Using continuous sulfate/sulfuric acid monitors built at Harvard, we are characterizing the magnitude, duration and frequency of acid aerosol events in each of our study cities. This information will be utilized in the analysis of the respiratory symptom data. The Harvard Air Pollution Health Study is providing information on the relationship among health variables and air pollutant exposures. In addition, this study will add to our understanding of lung growth and aging and the risk factors associated with chronic respiratory disabilities.

Adult↗
PubMed1983

Indoor air pollution: a public health perspective.

Although official efforts to control air pollution have traditionally focused on outdoor air, it is now apparent that elevated contaminant concentrations are common inside some private and public buildings. Concerns about potential public health problems due to indoor air pollution are based on evidence that urban residents typically spend more than 90 percent of their time indoors, concentrations of some contaminants are higher indoors than outdoors, and for some pollutants personal exposures are not characterized adequately by outdoor measurements. Among the more important indoor contaminants associated with health or irritation effects are passive tobacco smoke, radon decay products, carbon monoxide, nitrogen dioxide, formaldehyde, asbestos fibers, microorganisms, and aeroallergens. Efforts to assess health risks associated with indoor air pollution are limited by insufficient information about the number of people exposed, the pattern and severity of exposures, and the health consequences of exposures. An overall strategy should be developed to investigate indoor exposures, health effects, control options, and public policy alternatives.

Adolescent↗
PubMed1983

Estimating human exposure to nitrogen dioxide: an indoor/outdoor modeling approach.

Adverse health consequences associated with human exposure to nitrogen dioxide are well documented. In order for policymakers to assess health risks and implement appropriate control strategies, accurate information is required concerning (1) the number of people exposed, (2) the severity and patterns of exposure, and (3) the health-related effects of exposure. In the past, data from central monitoring sites have been used to establish air pollution exposures. However, it is now recognized that people spend much of their time indoors or in areas away from fixed monitors where pollutant concentrations may be drastically different. An attempt to provide a more realistic estimate of nitrogen dioxide exposures is made. A simple deterministic model is developed, relating exposure to background ambient levels, indoor values, and human activities. Ambient and indoor parameters are derived from monitoring programs in six U.S. cities. Results suggest indoor nitrogen dioxide concentrations in private dwellings vary primarily with outdoor levels and type of cooking fuel, but are also affected by factors such as air-exchange rates and strength of indoor sources. Estimates of population exposures are obtained by combining observed distributions of nitrogen dioxide concentrations from outdoor and indoor settings with information about number of people and time spent in each microenvironment.

Air Pollution↗
PubMed1979

Effects of sulfur oxides and respirable particles on human health. Methodology and demography of populations in study.

As part of a study of health effects of sulfur dioxide and particulate matter, we have established a cohort of adults 25 to 74 yr of age in 6 communities who will be followed prospectively. At the conclusion of our first cycle of measuring the health of adults in 6 sites we found that, although we used different sampling frames, our samples were close to the distribution shown in the U.S. Census for age, sex, and occupation, with the possible exception of one city. Analysis of the cross-sectional data indicated that for both age- and height-adjusted values for forced expiratory volume in 1 s and for selected rates of various respiratory symptoms standardized for age, differences among smoking groups were apparent. Differences in these parameters between sites suggest trends that were associated with levels of pollution. Further analyses of the prospective data currently being collected will be required before definitive statements can be made about the effect of specific levels of exposure.

Adult↗
PubMedDate not supplied

A critical evaluation of acute ozone epidemiology results.

Evidence from controlled human exposure studies demonstrates transient pulmonary functional responses to ozone exposure concentrations near the U.S. primary air quality standard of 0.120 ppm. There have been several recent efforts to document low concentration ozone effects in the epidemiological setting. Quantification of ozone effects under natural conditions of exposure can provide valuable information for risk assessment. However, results of epidemiological studies on acute ozone effects have had a limited role in decisions for air quality standards. This reflects difficulties in the quantitative interpretation of results that are to some extent inherent in the epidemiological approach, such as the difficulty of assessing individual exposures, failure to account for varying activity levels, and confounding by temporal covariates, e.g., temperature and pollen. However, in spite of the limitations of individual studies, when viewed as a group the epidemiological studies are consistent among themselves and with results from chamber studies.

Adolescent↗
PubMedDate not supplied

A study of respiratory illnesses in infants and nitrogen dioxide exposure.

Toxicologic and epidemiologic studies have elevated concern that exposure to nitrogen dioxide (NO2) in outdoor and indoor air may increase the frequency and severity of respiratory infections. We have developed and implemented a prospective cohort study to test the hypothesis that exposure to NO2 increases the incidence and severity of respiratory infections during the first 18 mo of life. This study, which was based on extensive pilot research, was designed to address the potential limitations of misclassification, confounding, and inadequate power. Enrollment of 1,315 subjects has been completed. This paper reviews the methods used in the study, characteristics of the enrolled subjects, NO2 concentrations in the homes of study participants, and rates of illness occurrence.

Air Pollution, Indoor↗
PubMedDate not supplied

A longitudinal analysis of the efficacy of environmental interventions on asthma-related quality of life and symptoms among children in urban public housing.

In an environmental intervention study in public housing, we examined monthly Juniper Paediatric Asthma Quality of Life (QOL) Questionnaires for 51 children. Longitudinal analysis and spline models were used to identify time periods with significant improvements in QOL to inform judgments about causality. We found significant improvements in QOL, with moderate improvements before environmental interventions, increased rates of improvement immediately after, and reduced rates more than 5 months post-intervention. Effect modification analyses identified high-risk subpopulations and emphasized the importance of environmental, social, and economic conditions. Our results demonstrate the value of longitudinal techniques in evaluating the benefits of environmental interventions for asthma.

Adolescent↗
PubMedDate not supplied

Wind velocity effects on sampling rate of NO2 badge.

The effects of wind velocity on a sampling rate of a nitrogen dioxide (NO2) diffusive badge were experimentally determined using a turntable. The use of a turntable permits the collection of the large amounts of data that are needed for statistically reliable results at several wind velocities in one experiment. The regression model for the wind effect determined by these experiments was closely correlated with data previously gathered from experiments using wind tunnels. Experiments at two different relative humidities, 35% and 60%, were performed and analyzed by a simple least square regression model. A multi-regression model containing two independent variables, wind velocity and relative humidity, also was developed. The multi-regression model was useful at relative humidity between 20% and 60% and wind velocity between 0 and 7 meter per second (m/sec).

Air Pollutants↗