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Biomedical subjects

B Brunekreef

Publications and source records attributed to B Brunekreef.

At least 181 records · Page 10Linked to original sources
PubMed1985

Indoor air pollution and its effect on pulmonary function of adult non-smoking women: I. Exposure estimates for nitrogen dioxide and passive smoking.

The potential effects of indoor NO2 and tobacco smoke on the respiratory system were studied using pulmonary function data from a longitudinal study. In 1982, NO2 was measured in 163 homes of non-smoking adult women and detailed information on smoking inside the house was gathered over the period 1965-1982. Personal exposure to NO2 was calculated from the measured levels and the activity pattern of the study population (range 11-139 micrograms NO2/m3). Historical exposure was estimated using regression models of NO2 on house characteristics. It is shown that estimation of historical exposure to indoor NO2 on the basis of house characteristics only is, at present, too inaccurate for use in epidemiological studies. Actual measurement of NO2 is unavoidable for exposure assessment in health effect studies of indoor exposure to NO2.

Adult↗
PubMed1985

Indoor air pollution and its effect on pulmonary function of adult non-smoking women: II. Associations between nitrogen dioxide and pulmonary function.

The association between nitrogen dioxide levels in homes and pulmonary function of 97 non-smoking adult women was investigated in a rural area in the Netherlands. The study population was a sub-sample of a longitudinal field study on chronic non-specific lung diseases which was started in 1965. Pulmonary function tests were performed at three-yearly intervals. NO2 was measured for one week in the winter in kitchen, living room and bedroom of each home. Cross-sectional analyses showed negative associations between NO2 exposure and several pulmonary function parameters as measured in the 1982 study. No significant association could be found between NO2 exposure and pulmonary function decline since the start of the study.

Adult↗
PubMed1985

Indoor air pollution and its effect on pulmonary function of adult non-smoking women: III. Passive smoking and pulmonary function.

The association between pulmonary function and exposure to tobacco smoke in the home was investigated in a sample of adult, non-smoking women living in a rural area. The women were all participants in a large longitudinal survey on the natural history and determinants of chronic non-specific lung disease. On cross-sectional analysis, several pulmonary function parameters were found to be significantly associated with exposure to tobacco smoke in the home. There was no association between exposure and pulmonary function decline.

Adult↗
PubMed1984

Indoor nitrogen dioxide pollution and respiratory symptoms of schoolchildren.

The influence of indoor nitrogen-dioxide exposure on respiratory symptoms of schoolchildren was investigated in a case-control study. The election method used was useful in obtaining symptomatic children, but insufficient in defining cases and controls without additional information. No relationship between indoor NO2 and respiratory symptoms was found. Bias may have been present, especially because of the high mobility of the study population. Attempts to estimate historical exposure were inaccurate. Therefore the results do not exclude that an association between indoor NO2 and respiratory symptoms exists.

Air Pollutants↗
PubMed1984

The relationship between air lead and blood lead in children: a critical review.

A review is given of community studies from which the relationship between air lead and blood lead in children of varying ages can be estimated. The review covers nineteen different studies which were carried out in ten different countries. The blood lead/air lead relationship is denoted with the symbol "alpha'. It is concluded that for children, a wide range of alpha-values can be estimated from the data in the different studies. Most values center on 3-5 rather than the 1-2 which is usually reported from adults. However, adjustment for confounders has been absent or incomplete in most, if not all studies. Most alpha-estimates thus have to be viewed with caution.

Adolescent↗
PubMed1983

Detecting indoor CO exposure by measuring CO in exhaled breath.

CO levels in exhaled breath were measured in 29 residents of flats, equipped with a flueless geiser (an instantaneous gas-fired water heater). The flats were selected because they had a geiser with a CO concentration of more than 250 parts per million in its flue gases. Small, but in some cases statistically significant increases in CO levels in exhaled breath were found in both smokers and non smokers, and after periods of cooking and dishwashing when the geisers had been used. Calculated COHb levels remained well below 2.5% for non smokers, but were generally higher for smokers.

Adolescent↗
PubMed1983

Lead uptake from vegetables grown along highways.

Blood-lead levels were measured in tenants of vegetable gardens located in close proximity to busy highways (average: greater than 25000 vehicles per workday) in the Netherlands. For comparison, blood-lead levels were determined in tenants of vegetable gardens located away from busy traffic. The results indicate that there is no significant difference between the geometric mean blood-lead levels of the two populations, despite a 2-3-fold difference in the lead content of their vegetables, and despite frequent consumption of these vegetables in the exposed group. Mean PbB-values were around 0.48 mumol/1 (100 micrograms/1), which is well below existing health guidelines and slightly below the levels found in another recent survey of Dutch suburban residents.

Adult↗
PubMed1982

Long-term average suspended particulate concentrations in smokers' homes.

Suspended particulate matter (SPM) concentrations were measured in about 100 homes in the city of Arnhem, The Netherlands. Most homes were sampled for 2 months continuously. Monthly average SPM concentrations ranged from 20-570 micrograms/m3. From 26 houses, smoking data were gathered at a later date. A clear relationship was found between SPM concentrations and number of smokers in the home.

Housing↗
PubMed1982

Indoor air pollution by carbon monoxide and nitrogen oxides.

The results of an exploratory survey of indoor levels of carbon monoxide and nitrogen dioxide from gas-fired cooking and waterheating appliances in the Dutch cities of Arnhem and Enschede in the fall of 1980 are reported. Measurements were carried out electrochemically (Ecolyzer 2000) or with Draeger tubes in the case of CO and with Palmes diffusion tubes (5 to 8 days exposure) in the case of NO2. For CO, in 18% (27%) of the homes visited the limit of 600 (300) ppm in the flue gases was exceeded, whereas the Dutch Installation Code Standard of 50 ppm CO in room air was exceeded in 17% of the homes. The arithmetic mean value of the NO2 concentration in 286 homes was 118 micrograms/m3 with a range of 35 to 472 micrograms/m3. The corresponding figures for living rooms were 58 and 35 to 346 micrograms/m3, respectively. Outdoor NO2 concentrations were 2 to 3 times lower than indoor concentrations.

Air Pollutants↗
PubMed1980

The feasibility of using lead in hair concentration in monitoring environmental exposure in children.

The feasibility of lead in hair as an indicator of lead exposure has been compared to that of lead in blood and zinc protoporphyrin in blood levels in 1--3-year-old children living within 1 km of a lead smelter. Lead exposure was measured as lead in house dust, outdoor and indoor lead in air concentrations, outdoor and indoor lead depositions, and subjective assessment of indoor dustiness. Lead in blood ranged from 51-353 microgram/l and lead in hair from 0.8-114 microgram/g. It can be concluded that within the range of environmental exposure studied, and for the age group concerned, measurement of lead in blood and of the zinc protoporphyrin in blood levels appear to be better biological parameters to assess both total environmental exposure and health risk than measurement of lead in hair level alone.

Child, Preschool↗
PubMedDate not supplied

Methodological approaches to the analysis of hierarchical studies of air pollution and respiratory health--examples from the CESAR study. Central European Study on Air pollution and Respiratory Health.

OBJECTIVES: Many studies of air pollution and health are carried out over several geographical areas, and sometimes over several countries. This paper explores three approaches to analysis in such studies: a non hierarchical model, a two-stage analysis, and multilevel modelling. Illustrations are given using a preliminary subset of data from the CESAR study. DESIGN: The Central European Study on Air pollution and Respiratory Health (CESAR) was conducted in 25 areas within six Central European countries, enrolling 20,271 schoolchildren. Pollution averages were calculated for each area. Associations between pollution and health outcomes were estimated under different models. MAIN RESULTS: A regression analysis of log FVC (forced vital capacity) on PM10, ignoring the geographical hierarchy, estimated a significant mean drop in FVC (adjusted for confounders) of 2.2% (95% CI 0.5% to 1.3%), p=0.007, from the area with the lowest PM10 to that with the highest. A multilevel model (mlm), using data for all children, but with random effects at area and country level, estimated a drop of 2.8% (-0.6% to 6.1%), p=0.110. A two-stage analysis (mean log FVC, adjusted for confounders, was estimated for each area using regression, and these means then regressed on PM10) estimated a drop of 2.6% (-0.5% to 5.5%), p=0.101. Simulation exercises showed the non hierarchical method to be very inadequate in the context of the CESAR study, with only half of all 95% confidence intervals for the estimated PM10 slope containing the true value (i.e., that used to create the simulated data). The two-stage and multilevel modelling methods gave results which were substantially better, though both underperformed slightly. All three methods appeared to give unbiased slope estimates. CONCLUSIONS: Acknowledgement of hierarchical structures is essential in statistical inference--standard errors can be substantially incorrect when they are ignored. Multilevel, random-effects models correctly address hierarchical structures, though having few units at higher levels can cause problems in convergence, especially where complex modelling is required. Two-stage analyses, acknowledging hierarchy, provide simple alternatives to random-effects models.

Air Pollutants↗
PubMedDate not supplied

Estimation of long-term average exposure to outdoor air pollution for a cohort study on mortality.

Recent prospective cohort studies have suggested that long-term exposure to low levels of particulate matter (PM) air pollution is associated with increased mortality due to, especially, cardio-pulmonary disease. Exposure to ambient air pollution was estimated mostly as city average concentrations, assuming homogenous exposure within the city. We used an ongoing cohort study - The Netherlands Cohort Study (NLCS) on diet and cancer - to investigate the relationship between traffic-related air pollution and mortality. The baseline data collection took place in 1986. A study was conducted to develop methods for exposure assessment and evaluate the contrast in exposure to air pollution within the cohort. Assessment of long-term exposure to two traffic-related air pollutants, Black Smoke (BS) and Nitrogen Dioxide (NO(2)), consisted of separate estimation of regional background, urban background, and local traffic contributions at the home address. Interpolation of concentration data from a routine monitoring network was used to estimate the regional background concentration. A regression model relating degree of urbanization to air pollution was used to allow for differences between different towns/neighborhoods of cities. Distance to major roads was calculated to characterize local traffic contributions, using a Geographic Information System (GIS). Interpolation resulted in reasonably precise regional background estimation when distant sites were not used and distance squared was used as the weight. Cross-validation showed that prediction errors were about 15% of the range in regional background concentration. Urban and local scales contributed significantly to the contrast within the cohort. Prediction errors for estimating the urban background were about 25% of the range in background concentrations. When the developed model was applied to the study cohort, there was substantial contrast in estimated exposure to BS and NO(2). About 90% of the study population lived 10 years or more at its 1986 home address - supporting the use of the estimated concentration at the 1986 address as a relevant exposure variable.

Aged↗
PubMedDate not supplied

Acute effects of a winter air pollution episode on pulmonary function and respiratory symptoms of children.

The acute respiratory effects of a wintertime air pollution episode were studied in a general population sample of 112 children who were 7-12 y of age and who lived in a nonurban community. Spirometry was performed on 6 d, with a fixed interval of 3 wk between successive tests. During an air pollution episode, an additional pulmonary function test was made. Acute respiratory symptoms of the children were noted in a diary. Ambient concentrations of sulfur dioxide, black smoke, particulate matter with an aerodynamic diameter less than 10 microns, and nitrogen dioxide were considered as exposure variables. The association of air pollution with pulmonary function and prevalence of acute respiratory symptoms was assessed by individual linear regression analysis and time series analysis, respectively. In February 1991, an air pollution episode occurred during which daily average sulfur dioxide concentrations were slightly above 100 micrograms/m3, and particulate matter (with an aerodynamic diameter of less than 10 microns) concentrations reached 174 micrograms/m3. During the episode, forced vital capacity, forced expiratory volume in 1 s, and maximal mid-expiratory flow were lower than on baseline tests. Significant negative associations were found between the concentration of sulfur dioxide, black smoke, and particulate matter with an aerodynamic diameter of less than 10 microns. No association between prevalence of acute respiratory symptoms and the concentration of these compounds was found.

Acute Disease↗