Dataset Information

Are noise and air pollution related to the incidence of dementia? A cohort study in London, England.

ABSTRACT:

Objective

To investigate whether the incidence of dementia is related to residential levels of air and noise pollution in London.

Design

Retrospective cohort study using primary care data.

Setting

75 Greater London practices.

Participants

130?978 adults aged 50-79 years registered with their general practices on 1 January 2005, with no recorded history of dementia or care home residence.

Primary and secondary outcome measures

A first recorded diagnosis of dementia and, where specified, subgroups of Alzheimer's disease and vascular dementia during 2005-2013. The average annual concentrations during 2004 of nitrogen dioxide (NO₂), particulate matter with a median aerodynamic diameter ?2.5?µm (PM_2.5) and ozone (O₃) were estimated at 20×20?m resolution from dispersion models. Traffic intensity, distance from major road and night-time noise levels (L_night) were estimated at the postcode level. All exposure measures were linked anonymously to clinical data via residential postcode. HRs from Cox models were adjusted for age, sex, ethnicity, smoking and body mass index, with further adjustments explored for area deprivation and comorbidity.

Results

2181 subjects (1.7%) received an incident diagnosis of dementia (39% mentioning Alzheimer's disease, 29% vascular dementia). There was a positive exposure response relationship between dementia and all measures of air pollution except O₃, which was not readily explained by further adjustment. Adults living in areas with the highest fifth of NO₂ concentration (>41.5?µg/m³) versus the lowest fifth (<31.9?µg/m³) were at a higher risk of dementia (HR=1.40, 95%?CI 1.12 to 1.74). Increases in dementia risk were also observed with PM_2.5, PM_2.5 specifically from primary traffic sources only and L_night, but only NO₂ and PM_2.5 remained statistically significant in multipollutant models. Associations were more consistent for Alzheimer's disease than vascular dementia.

Conclusions

We have found evidence of a positive association between residential levels of air pollution across London and being diagnosed with dementia, which is unexplained by known confounding factors.

SUBMITTER: Carey IM

PROVIDER: S-EPMC6144407 | biostudies-literature | 2018 Sep

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Are noise and air pollution related to the incidence of dementia? A cohort study in London, England.

Carey Iain M IM Anderson H Ross HR Atkinson Richard W RW Beevers Sean D SD Cook Derek G DG Strachan David P DP Dajnak David D Gulliver John J Kelly Frank J FJ

BMJ open 20180911 9

<h4>Objective</h4>To investigate whether the incidence of dementia is related to residential levels of air and noise pollution in London.<h4>Design</h4>Retrospective cohort study using primary care data.<h4>Setting</h4>75 Greater London practices.<h4>Participants</h4>130 978 adults aged 50-79 years registered with their general practices on 1 January 2005, with no recorded history of dementia or care home residence.<h4>Primary and secondary outcome measures</h4>A first recorded diagnosis of deme ...[more]

PMID: 30206085

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Project description:ObjectiveTo investigate the association between long term residential exposure to road traffic and railway noise and risk of incident dementia.DesignNationwide prospective register based cohort study.SettingDenmark.Participants1 938 994 adults aged ≥60 years living in Denmark between 1 January 2004 and 31 December 2017.Main outcome measuresIncident cases of all cause dementia and dementia subtypes (Alzheimer's disease, vascular dementia, and Parkinson's disease related dementia), identified from national hospital and prescription registries.ResultsThe study population included 103 500 participants with incident dementia, and of those, 31 219 received a diagnosis of Alzheimer's disease, 8664 of vascular dementia, and 2192 of Parkinson's disease related dementia. Using Cox regression models, 10 year mean exposure to road traffic and railway noise at the most (Ldenmax) and least (Ldenmin) exposed façades of buildings were associated with a higher risk of all cause dementia. These associations showed a general pattern of higher hazard ratios with higher noise exposure, but with a levelling off or even small declines in risk at higher noise levels. In subtype analyses, both road traffic noise and railway noise were associated with a higher risk of Alzheimer's disease, with hazard ratios of 1.16 (95% confidence interval 1.11 to 1.22) for road Ldenmax ≥65 dB compared with <45 dB, 1.27 (1.22 to 1.34) for road Ldenmin ≥55 dB compared with <40 dB, 1.16 (1.10 to 1.23) for railway Ldenmax ≥60 dB compared with <40 dB, and 1.24 (1.17 to 1.30) for railway Ldenmin ≥50 dB compared with <40 dB. Road traffic, but not railway, noise was associated with an increased risk of vascular dementia. Results indicated associations between road traffic Ldenmin and Parkinson's disease related dementia.ConclusionsThis nationwide cohort study found transportation noise to be associated with a higher risk of all cause dementia and dementia subtypes, especially Alzheimer's disease.

Project description:Objective To investigate the relation between exposure to both air and noise pollution from road traffic and birth weight outcomes.Design Retrospective population based cohort study.Setting Greater London and surrounding counties up to the M25 motorway (2317 km2), UK, from 2006 to 2010.Participants 540 365 singleton term live births.Main outcome measures Term low birth weight (LBW), small for gestational age (SGA) at term, and term birth weight.Results Average air pollutant exposures across pregnancy were 41 μg/m3 nitrogen dioxide (NO2), 73 μg/m3 nitrogen oxides (NOx), 14 μg/m3 particulate matter with aerodynamic diameter <2.5 μm (PM2.5), 23 μg/m3 particulate matter with aerodynamic diameter <10 μm (PM10), and 32 μg/m3 ozone (O3). Average daytime (LAeq,16hr) and night-time (Lnight) road traffic A-weighted noise levels were 58 dB and 53 dB respectively. Interquartile range increases in NO2, NOx, PM2.5, PM10, and source specific PM2.5 from traffic exhaust (PM2.5 traffic exhaust) and traffic non-exhaust (brake or tyre wear and resuspension) (PM2.5 traffic non-exhaust) were associated with 2% to 6% increased odds of term LBW, and 1% to 3% increased odds of term SGA. Air pollutant associations were robust to adjustment for road traffic noise. Trends of decreasing birth weight across increasing road traffic noise categories were observed, but were strongly attenuated when adjusted for primary traffic related air pollutants. Only PM2.5 traffic exhaust and PM2.5 were consistently associated with increased risk of term LBW after adjustment for each of the other air pollutants. It was estimated that 3% of term LBW cases in London are directly attributable to residential exposure to PM2.5>13.8 μg/m3during pregnancy.Conclusions The findings suggest that air pollution from road traffic in London is adversely affecting fetal growth. The results suggest little evidence for an independent exposure-response effect of traffic related noise on birth weight outcomes.

Dataset Information

Are noise and air pollution related to the incidence of dementia? A cohort study in London, England.

Objective

Design

Setting

Participants

Primary and secondary outcome measures

Results

Conclusions

Publications

Are noise and air pollution related to the incidence of dementia? A cohort study in London, England.

Similar Datasets

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