Dataset Information

Nitrogen dioxide levels estimated from land use regression models several years apart and association with mortality in a large cohort study.

ABSTRACT:

Background

Land Use Regression models (LUR) are useful to estimate the spatial variability of air pollution in urban areas. Few studies have evaluated the stability of spatial contrasts in outdoor nitrogen dioxide (NO?) concentration over several years. We aimed to compare measured and estimated NO? levels 12 years apart, the stability of the exposure estimates for members of a large cohort study, and the association of the exposure estimates with natural mortality within the cohort.

Methods

We measured NO? at 67 locations in Rome in 1995/96 and 78 sites in 2007, over three one-week-long periods. To develop LUR models, several land-use and traffic variables were used. NO? concentration at each residential address was estimated for a cohort of 684,000 adults. We used Cox regression to analyze the association between the two estimated exposures and mortality.

Results

The mean NO? measured concentrations were 45.4??g/m³ (SD 6.9) in 1995/96 and 44.6??g/m³ (SD 11.0) in 2007, respectively. The correlation of the two measurements was 0.79. The LUR models resulted in adjusted R2 of 0.737 and 0.704, respectively. The correlation of the predicted exposure values for cohort members was 0.96. The association of each 10??g/m³ increase in NO? with mortality was 6?% for 1995/96 and 4?% for 2007 LUR models. The increased risk per an inter-quartile range change was identical (4?%, 95?% CI:3-6?%) for both estimates of NO?.

Conclusions

Measured and predicted NO? values from LUR models, from samples collected 12 years apart, had good agreement, and the exposure estimates were similarly associated with mortality in a large cohort study.

SUBMITTER: Cesaroni G

PROVIDER: S-EPMC3407745 | biostudies-literature | 2012 Jul

REPOSITORIES: biostudies-literature

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Publications

Nitrogen dioxide levels estimated from land use regression models several years apart and association with mortality in a large cohort study.

Cesaroni Giulia G Porta Daniela D Badaloni Chiara C Stafoggia Massimo M Eeftens Marloes M Meliefste Kees K Forastiere Francesco F

Environmental health : a global access science source 20120718

<h4>Background</h4>Land Use Regression models (LUR) are useful to estimate the spatial variability of air pollution in urban areas. Few studies have evaluated the stability of spatial contrasts in outdoor nitrogen dioxide (NO₂) concentration over several years. We aimed to compare measured and estimated NO₂ levels 12 years apart, the stability of the exposure estimates for members of a large cohort study, and the association of the exposure estimates with natural mortality within the cohort.<h4> ...[more]

PMID: 22808928

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Project description:BACKGROUND:Cognitive impairment is a major contributor to mortality among the elderly. However, the relationship between cognitive impairment evaluated by educational levels and mortality and the trend between cognitive impairment and mortality with time are unclear. We aim to evaluate the differences in associations of cognitive impairment, taking the stratification by educational levels into account, with all-cause mortality and further explore the relationship of cognitive impairment with mortality in different age and sex groups in two cohorts ascertained 6?years apart in China. METHODS:A total of 13,906 and 13,873 Chinese elderly aged 65?years and older were included in the 2002-2008 and 2008-2014 cohorts from the Chinese Longitudinal Healthy Longevity Survey (CLHLS). Mortality data was ascertained from interviews with family members or relatives of participants. Cognitive function, evaluated by the Mini-Mental State Examination (MMSE), were defined by different cut-offs taking educational background into account. Cox models were used to explore the relationship of cognitive impairment with mortality. RESULTS:For the 2002-2008 and 2008-2014 cohorts, 55,277 and 53,267 person-years were followed up, and the mean (SD) age were 86.5 (11.6) and 87.2 (11.3) years, respectively. Compared to normal cognition, cognitive impairment was independently associated with higher mortality risk after controlling for potential confounders, with hazard ratios (HRs) of 1.32 (95% confidence interval [CI], 1.25-1.39) in 2002-2008 cohort and 1.26 (95% CI, 1.19-1.32) in 2008-2014 cohort, stratified by educational levels. The trend of cognitive impairment with all-cause mortality risk decreased from 2002 to 2008 to 2008-2014 cohort, while no significant interaction of cognitive impairment with cohort for all-cause mortality was observed. The associations of cognitive impairment and mortality were decreased with age in the two cohorts. CONCLUSIONS:Cognitive impairment evaluated by different cut-offs were associated with increased risk of mortality, especially among those aged 65-79?years in the two cohorts; this advocates that periodic screening for cognitive impairment among the elderly is warranted.

Project description:BackgroundAmbient air pollution is among the greatest environmental risks to human health. However, little is known about the health effects of nitrogen dioxide (NO2), a traffic-related air pollutant. Herein, we aimed to conduct a meta-analysis to investigate the long-term effects of NO2 on mortality.MethodsWe conducted a systematic search for studies that were published up to February 2020 and performed a meta-analysis of all available epidemiologic studies evaluating the associations between long-term exposure to NO2 with all-cause, cardiovascular, and respiratory mortality. Overall pooled effect estimates as well as subgroup-specific pooled estimates (e.g. location, exposure assessment method, exposure metric, study population, age at recruitment, and key confounder adjustment) and 95% confidence intervals were calculated using random-effects models. Risk of bias assessment was accessed by following WHO global air quality guidelines. Publication bias was accessed by visually inspecting funnel plot and Egger's liner regression was used to test of asymmetry.ResultsOur search initially retrieved 1349 unique studies, of which 34 studies met the inclusion criteria. The pooled hazard ratio (HR) for all-cause mortality was 1.06 (95%CI: 1.04-1.08, n = 28 studies, I2 = 98.6%) per 10 ppb increase in annual NO2 concentrations. The pooled HRs for cardiovascular and respiratory mortality per 10 ppb increment were 1.11 (95%CI: 1.07-1.16, n = 20 studies, I2 = 99.2%) and 1.05 (95%CI: 1.02-1.08, n = 17 studies, I2 = 94.6%), respectively. The sensitivity analysis pooling estimates from multi-pollutant models suggest an independent effect of NO2 on mortality. Funnel plots indicate that there is no evidence for publication bias in our study.ConclusionWe provide robust epidemiological evidence that long-term exposure to NO2, a proxy for traffic-sourced air pollutants, is associated with a higher risk of all-cause, cardiovascular, and respiratory mortality that might be independent of other common air pollutants.

Dataset Information

Nitrogen dioxide levels estimated from land use regression models several years apart and association with mortality in a large cohort study.

Background

Methods

Results

Conclusions

Publications

Nitrogen dioxide levels estimated from land use regression models several years apart and association with mortality in a large cohort study.

Similar Datasets

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