Home About us Contact
|
Home About us Contact | ||
|
|
||
Ambient Air Pollution (ambient + air_pollution)
Selected AbstractsAir pollution and hospitalization for venous thromboembolic disease in ChileJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 4 2010R. E. DALES See also Mannucci PM. Fine particulate: it matters. This issue, pp 659,61; Bonzini M, Tripodi A, Artoni A, Tarantini L, Marinelli B, Bertazzi PA, Apostoli P, Baccarelli A. Effects of inhalable particulate matter on blood coagulation. This issue, pp 662,8. Summary.,Background:,Ambient air pollution is a risk factor for stroke and myocardial infarction, possibly because of alterations in coagulation that influence the arterial circulation. Whether air pollution influences diseases associated with peripheral venous thrombogenesis remains largely unknown. Objectives: To determine the association between air pollution and venous thromboembolic disease (VTE) in a sample of the general population. Methods: A time-series analysis was used to test the association between daily air pollution and VTE hospitalizations in Santiago between 2001 and 2005. Results were adjusted for long-term trends, day of the week and average daily humidex. Results: From a population of 5.4 million, there were, on average, 2.3 admissions for VTE per day. Pooled estimates of relative risk (RR) [95% confidence interval (CI)] of hospitalization for venous disease were: 1.07 (1.05, 1.09) for a 58.4 p.p.b. increase in ozone (O3); 1.06 (1.02, 1.09) for a 5.85 p.p.b. increase in sulphur dioxide (SO2); 1.08 (1.03, 1.12) for a 29.25 ,g/m3 increase in nitrogen dioxide (NO2); and 1.05 (1.03, 1.06) for a 20.02 ,g/m3 increase in particulate matter , 2.5 ,m in mean aerodynamic diameter (PM2.5). For pulmonary embolism (PE) results were: 1.10 (1.07, 1.13) for O3; 1.05 (1.02, 1.08) for SO2; 1.07 (1.04, 1.09) for NO2; and 1.05(1.03, 1.06) for PM2.5, respectively. Conclusion: Air pollution appears to be a risk factor for venous thrombosis and PE, a disease with a significant fatality rate. [source] Assessing sources of variability in measurement of ambient particulate matterENVIRONMETRICS, Issue 6 2001Michael J. Daniels Abstract Particulate matter (PM), a component of ambient air pollution, has been the subject of United States Environmental Protection Agency regulation in part due to many epidemiological studies examining its connection with health. Better understanding the PM measurement process and its dependence on location, time, and other factors is important for both modifying regulations and better understanding its effects on health. In light of this, in this paper, we will explore sources of variability in measuring PM including spatial, temporal and meteorological effects. In addition, we will assess the degree to which there is heterogeneity in the variability of the micro-scale processes, which may suggest important unmeasured processes, and the degree to which there is unexplained heterogeneity in space and time. We use Bayesian hierarchical models and restrict attention to the greater Pittsburgh (USA) area in 1996. The analyses indicated no spatial dependence after accounting for other sources of variability and also indicated heterogeneity in the variability of the micro-scale processes over time and space. Weather and temporal effects were very important and there was substantial heterogeneity in these effects across sites. Copyright © 2001 John Wiley & Sons, Ltd. [source] Air Pollution and Daily Emergency Department Visits for Headache in Montreal, CanadaHEADACHE, Issue 3 2008Mieczyslaw Szyszkowicz PhD Background., Many studies have indicated that weather can trigger headache. Here we propose a new methodological approach to assess the relationship between weather, ambient air pollution, and emergency department (ED) visits for this condition. Objective., To examine the associations between ED visits for headache and selected meteorological and air pollution factors. Design and Methods., A hierarchical clusters design was used to study 10,497 ED visits for headache (ICD-9: 784) that occurred at a Montreal hospital between 1997 and 2002. The generalized linear mixed models technique was applied to create Poisson models for the clustered counts of visits for headache. Results., Statistically significant positive associations were observed between the number of ED visits for headache and the atmospheric pressure for all and for female visits for 1-day and 2-day lagged exposures. The percentage increase in daily ED female visits was 4.1% (95% CI: 2.0, 6.2), 3.4% (95% CI: 1.4, 5.6), and 2.2% (95% CI: 1.4, 5.6) for current day, 1-day and 2-day lagged exposure to SO2, respectively, for an increase of an interquartile range (IQR) of 2.4 ppb. The percentage increase was also statistically significant for current day and 1-day lagged exposure to NO2 and CO for all and for female visits. Conclusions., Presented findings provide support for the hypothesis that ED visits for headache are correlated to weather conditions and ambient air pollution , to atmospheric pressure and exposure to SO2, NO2, CO, and PM2.5. An increase in levels of these factors is associated with an increase in the number of ED visits for headache. [source] A Bayesian hierarchical distributed lag model for estimating the time course of risk of hospitalization associated with particulate matter air pollutionJOURNAL OF THE ROYAL STATISTICAL SOCIETY: SERIES C (APPLIED STATISTICS), Issue 1 2009Roger D. Peng Summary., Time series studies have provided strong evidence of an association between increased levels of ambient air pollution and increased hospitalizations, typically at a single lag of 0, 1 or 2 days after an air pollution episode. Two important scientific objectives are to understand better how the risk of hospitalization that is associated with a given day's air pollution increase is distributed over multiple days in the future and to estimate the cumulative short-term health effect of an air pollution episode over the same multiday period. We propose a Bayesian hierarchical distributed lag model that integrates information from national health and air pollution databases with prior beliefs of the time course of risk of hospitalization after an air pollution episode. This model is applied to air pollution and health data on 6.3 million enrollees of the US Medicare system living in 94 counties covering the years 1999,2002. We obtain estimates of the distributed lag functions relating fine particulate matter pollution to hospitalizations for both ischaemic heart disease and acute exacerbation of chronic obstructive pulmonary disease, and we use our model to explore regional variation in the health risks across the USA. [source] ASSOCIATIONS BETWEEN AIR POLLUTION AND HOSPITAL VISITS FOR CARDIOVASCULAR DISEASES IN THE ELDERLY IN SYDNEY USING BAYESIAN STATISTICAL METHODSAUSTRALIAN & NEW ZEALAND JOURNAL OF STATISTICS, Issue 3 2009Hiep Duc Summary Using generalized linear models (GLMs), Jalaludin,et al. (2006;,J. Exposure Analysis and Epidemiology,16, 225,237) studied the association between the daily number of visits to emergency departments for cardiovascular disease by the elderly (65+) and five measures of ambient air pollution. Bayesian methods provide an alternative approach to classical time series modelling and are starting to be more widely used. This paper considers Bayesian methods using the dataset used by Jalaludin,et al.,(2006), and compares the results from Bayesian methods with those obtained by Jalaludin,et al.,(2006) using GLM methods. [source] Oral cleft defects and maternal exposure to ambient air pollutants in New Jersey,BIRTH DEFECTS RESEARCH, Issue 4 2010Elizabeth G. Marshall BACKGROUND Evidence links exposure to ambient air pollution during pregnancy, particularly gaseous pollutants and particulate matter, to an increased risk of adverse reproductive outcomes though the results for birth defects have been inconsistent. METHODS We compared estimated exposure to ambient air pollutants during early pregnancy among mothers of children with oral cleft defects (cases) to that among mothers of controls, adjusting for available risk factors from birth certificates. We obtained ambient air pollutant data from air monitoring sites in New Jersey for carbon monoxide (CO), nitrogen dioxide (NO2), ozone (O3), sulfur dioxide (SO2), particulate matter <10 ,m in aerodynamic diameter (PM10) and particulate matter <2.5 ,m in aerodynamic diameter (PM2.5). We used values from the nearest monitor (within 40 km of the residence at birth) for controls, cleft lip with or without cleft palate (CLP) and cleft palate only (CPO). RESULTS Based on logistic regression analyses for each contaminant and all contaminants together, there were no consistent elevated associations between selected air pollutants and cleft malformations. Quartile of CO concentration showed a consistent protective association with CPO (p < 0.01). For other contaminants, confidence intervals (95%) of the odds ratios for some quartiles excluded one. CLP showed limited evidence of an association with increasing SO2 exposure while CPO showed weak associations with increasing O3 exposure. CONCLUSION There was little consistent evidence associating cleft malformations with maternal exposure to ambient air pollutants. Evaluating particular pollutants or disease subgroups would require more detailed measurement of exposure and classification of cleft defects. Birth Defects Research (Part A), 2010. © 2010 Wiley-Liss, Inc. [source] Environmental factors, parental atopy and atopic eczema in primary-school children: a cross-sectional study in TaiwanBRITISH JOURNAL OF DERMATOLOGY, Issue 6 2007Y-L. Lee Summary Background, Parental atopy and environmental exposure are recognized risk factors for atopic eczema (AE) in childhood. However, the relative contributions of specific risk factors and the overall contributions of hereditary and environmental exposure remain unexplored. Objectives, To identify risk factors, estimate the population attributable risk (PAR) of environmental exposure, and compare the AE data for boys vs. girls in primary-school children. Methods, During a February to June 2001 cross-sectional, Taiwan-based questionnaire survey, we investigated 23 980 children from 22 primary schools, all located within 1 km of an air-monitoring station. Results, The 12-month prevalence of AE was reported as 6·1% in boys and 4·9% in girls. In both sexes, the risk of AE was strongly associated with parental atopy and perceived ambient air pollution. The presence of cockroaches [odds ratio (OR) 1·18, 95% confidence interval (CI) 1·00,1·40] and visible mould on walls at home (OR 1·46, 95% CI 1·22,1·70) were also significantly related to AE for girls; however, only visible mould on walls (and not the presence of cockroaches) at home was related to AE for boys (OR 1·40, 95% CI 1·18,1·66). While mutually adjusted models were applied, we found adjusted ORs and PARs were similar in boys and girls in hereditary and outdoor environmental factors. The PAR of indoor environmental factors was higher in girls (8·4%) than in boys (5·5%). There was no interaction between parental atopy and environmental factors. Conclusions, Parental atopy contributed more to AE than indoor or outdoor environmental factors. Girls may be more susceptible to indoor environmental factors than boys. [source] | |||||||||||||