Surrounding green, air pollution, traffic noise exposure and non-accidental and cause-specific mortality

Comparison of associations between mortality and air pollution exposure estimated with a hybrid, a land-use regression and a dispersion model

INTRODUCTION

To characterize air pollution exposure at a fine spatial scale, different exposure assessment methods have been applied. Comparison of associations with health from different exposure methods are scarce. The aim of this study was to evaluate associations of air pollution based on hybrid, land-use regression (LUR) and dispersion models with natural cause and cause-specific mortality.

METHODS

We followed a Dutch national cohort of approximately 10.5 million adults aged 29+ years from 2008 until 2012. We used Cox proportional hazard models with age as underlying time scale and adjusted for several potential individual and area-level socio-economic status confounders to evaluate associations of annual average residential NO2, PM2.5 and BC exposure estimates based on two stochastic models (Dutch LUR, European-wide hybrid) and deterministic Dutch dispersion models.

RESULTS

Spatial variability of PM2.5 and BC exposure was smaller for LUR compared to hybrid and dispersion models. NO2 exposure variability was similar for the three methods. Pearson correlations between hybrid, LUR and dispersion modeled NO2 and BC ranged from 0.72 to 0.83; correlations for PM2.5 were slightly lower (0.61-0.72). In general, all three models showed stronger associations of air pollutants with respiratory disease and lung cancer mortality than with natural cause and cardiovascular disease mortality. The strength of the associations differed between the three exposure models. Associations of air pollutants estimated by LUR were generally weaker compared to associations of air pollutants estimated by hybrid and dispersion models. For natural cause mortality, we found a hazard ratio (HR) of 1.030 (95% confidence interval (CI): 1.019, 1.041) per 10 µg/m3 for hybrid modeled NO2, a HR of 1.003 (95% CI: 0.993, 1.013) per 10 µg/m3 for LUR modeled NO2 and a HR of 1.015 (95% CI: 1.005, 1.024) per 10 µg/m3 for dispersion modeled NO2.

CONCLUSION

Air pollution was positively associated with natural cause and cause-specific mortality, but the strength of the associations differed between the three exposure models. Our study documents that the selected exposure model may contribute to heterogeneity in effect estimates of associations between air pollution and health.

Algorithm for Reducing Truck Noise on Via Baltica Transport Corridors in Lithuania

The section of Via Baltica going through the territory of the Republic of Lithuania is the most traffic intensive land logistics corridor in the country. The annual transportation volume has been increasing on this road; thus, the reduction of pollution caused by vehicles has become important. If gas emissions are regulated, and carriers have to pay pollution taxes, this does not apply to noise levels. The article presents the traffic intensity in this logistics corridor, measurements of the noise level at the characteristic points, its relation to the number of vehicles passing through it and an expert evaluation of proposed methods for noise energy reduction. Environmental noise is an unwanted or harmful sound that propagates in terms of both duration and geographical coverage. Noise is associated with many human activities, but road, rail and air traffic noises have the greatest impact. Due to irrationally arranged transport network, the transit flow of freight transport crosses residential areas of the city, places of rest and recreation of the population, causing high noise levels in adjacent areas. This is the biggest problem for the urban environment. Environmental noise affects many Europeans and is therefore considered by society to be one of the biggest environmental problems. This article presents an assessment of a new traffic noise algorithm. The presented expert survey on noise energy reduction allows choosing the most appropriate method for reducing noise energy in Via Baltica transport logistics corridor. Based on the expert survey, a hierarchical table for noise energy reduction was compiled. It will allow assessing the validity of individual noise energy reduction solutions. It has become relevant for improving infrastructure of other transport corridors and choosing the most appropriate solutions to reduce vehicle noise pollution. A further application of this model can be focused on economic evaluation, forecasting of expected benefits and so on.

Urban green space, tree canopy and 11-year risk of dementia in a cohort of 109,688 Australians

INTRODUCTION

Urban greening is a climate change-related policy with considerable health benefits. But do these benefits extend to prevention of dementia and, if so, which types of green space matter?

METHOD

Multilevel discrete time-to-event cohort study of incident Alzheimer's disease over 11 years among a baseline recruited between January 1, 2006 and December 31, 2009 (the Sax Institute's 45 and Up Study). Sampled participants for this study (N=109,688) were aged 45 years or older with no record of dementia up to 6 years before baseline, living in the cities of Sydney, Wollongong and Newcastle, Australia. Exposures were percentage total green space, tree canopy and open grass within 1.6-km road network distance buffers at baseline. Outcomes were time-to-first anti-dementia medication prescription (Department of Human Services) or dementia detected during hospitalisation or death up to 31 December 2016 (up to 11 years follow-up). Outcomes were analysed in parallel to triangulate on associations with green space, while testing for bias due to potential under-prescribing of anti-dementia medications. Models were adjusted for baseline person-level factors and area-level socioeconomic disadvantage.

RESULTS

Dementia detection varied by case ascertainment method. 1.55% (1,703/109,688) persons were detected using prescribed anti-dementia medications. 3.32% (3,639/109,688) persons were detected during hospitalisation or death via ICD-10 codes. Dementia incidence irrespective of outcome measurement was lower among females, younger participants, those living in couples, with higher qualifications and higher incomes. Dementia risk was lower with more tree canopy when the outcome was measured using hospital and death records (≥30% vs <10% tree canopy incidence hazard ratio (IHR) = 0.86, 95%CI 0.75, 0.99), after adjusting for person-level factors. The opposite association was observed when anti-dementia medications were used to detect dementia (≥30% vs <10% tree canopy IHR = 1.33, 95%CI 1.07, 1.66). Anti-dementia medication-based detection also indicated lower dementia risk with more open grass (≥20% vs <5% IHR = 0.83, 95%CI 0.67, 1.03). Anti-dementia medication prescribing was lower in the highest vs. lowest area-level disadvantage tertile (29.8% vs. 43.7%) among people diagnosed with dementia, indicating potential bias from geographic differences in prescribing practices. Adjusting for area-level disadvantage explained associations between tree canopy, open grass and dementia when detected by anti-dementia medication, but had negligible impact on negative (i.e. potentially protective) association between tree canopy and dementia detected by hospital and death records (≥30% vs <10% tree canopy hazard ratio 0.84, 95%CI 0.72, 0.99).

CONCLUSIONS

Increasing urban tree canopy cover may help to reduce the risk of dementia. Replication in contrasting contexts and mediation studies to assess pathways are warranted.

Long-term exposure to NO2 and O3 and all-cause and respiratory mortality: A systematic review and meta-analysis

BACKGROUND

WHO has published several volumes of Global Air Quality Guidelines to provide guidance on the health risks associated with exposure to outdoor air pollution. As new scientific evidence is generated, air quality guidelines need to be periodically revised and, where necessary, updated.

OBJECTIVES

The aims of the study were 1) to summarise the available evidence on the effect of long-term exposure to ozone (O3) and nitrogen dioxide (NO2) on mortality; 2) and to assess concentration response functions (CRF), their shape and the minimum level of exposures measured in studies to support WHO's update of the global air quality guidelines.

DATA SOURCES

We conducted a systematic literature search of the Medline, Embase and Web of Science databases following a protocol proposed by WHO and applied Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines for reporting our results.

STUDY ELIGIBILITY CRITERIA

Cohort studies in human populations (including sub-groups at risk) exposed to long-term concentrations of NO2 and O3. Outcomes assessed were all-cause, respiratory, Chronic Obstructive Pulmonary Disease (COPD) and Acute Lower Respiratory Infection (ALRI) mortality.

STUDY APPRAISAL AND SYNTHESIS METHODS

Studies included in the meta-analyses were assessed using a new Risk of Bias instrument developed by a group of experts convened by WHO. Study results are presented in forest plots and quantitative meta-analyses were conducted using random effects models. The certainty of evidence was assessed using a newly developed adaptation of GRADE.

RESULTS

The review identified 2068 studies of which 95 were subject to full-text review with 45 meeting the inclusion criteria. An update in September 2018 identified 159 studies with 1 meeting the inclusion criteria. Of the 46 included studies, 41 reported results for NO2 and 20 for O3. The majority of studies were from the USA and Europe with the remainder from Canada, China and Japan. Forty-two studies reported results for all-cause mortality and 22 for respiratory mortality. Associations for NO2 and mortality were positive; random-effects summary relative risks (RR) were 1.02 (95% CI: 1.01, 1.04), 1.03 (1.00, 1.05), 1.03 (1.01, 1.04) and 1.06 (1.02, 1.10) per 10 μg/m3 for all-cause (24 cohorts), respiratory (15 cohorts), COPD (9 cohorts) and ALRI (5 cohorts) mortality respectively. The review identified high levels of heterogeneity for all causes of death except COPD. A small number of studies investigated the shape of the concentration-response relationship and generally found little evidence to reject the assumption of linearity across the concentration range. Studies of O3 using annual metrics showed the associations with all-cause and respiratory mortality were 0.97 (0.93, 1.02) and 0.99 (0.89, 1.11) per 10 μg/m3 respectively. For studies using peak O3 metrics, the association with all-cause mortality was 1.01 (1.00, 1.02) and for respiratory mortality 1.02 (0.99, 1.05), each per 10 μg/m3. The review identified high levels of heterogeneity. Few studies investigated the shape of the concentration-response relationship. Certainty in the associations (adapted GRADE) with mortality was rated low to moderate for each exposure-outcome pair, except for NO2 and COPD mortality which was rated high.

LIMITATIONS

The substantial heterogeneity for most outcomes in the review requires explanation. The evidence base is limited in terms of the geographical spread of the study populations and, for some outcomes, the small number of independent cohorts for meta-analysis precludes meaningful meta-regression to explore causes of heterogeneity. Relatively few studies assessed specifically the shape of the CRF or multi-pollutant models.

CONCLUSIONS

The short-comings in the existing literature base makes determining the precise nature (magnitude and linearity) of the associations challenging. Certainty of evidence assessments were moderate or low for both NO2 and O3 for all causes of mortality except for NO2 and COPD mortality where the certainty of the evidence was judged as high.

Outdoor air pollution and cancer: An overview of the current evidence and public health recommendations

Outdoor air pollution is a major contributor to the burden of disease worldwide. Most of the global population resides in places where air pollution levels, because of emissions from industry, power generation, transportation, and domestic burning, considerably exceed the World Health Organization's health-based air-quality guidelines. Outdoor air pollution poses an urgent worldwide public health challenge because it is ubiquitous and has numerous serious adverse human health effects, including cancer. Currently, there is substantial evidence from studies of humans and experimental animals as well as mechanistic evidence to support a causal link between outdoor (ambient) air pollution, and especially particulate matter (PM) in outdoor air, with lung cancer incidence and mortality. It is estimated that hundreds of thousands of lung cancer deaths annually worldwide are attributable to PM air pollution. Epidemiological evidence on outdoor air pollution and the risk of other types of cancer, such as bladder cancer or breast cancer, is more limited. Outdoor air pollution may also be associated with poorer cancer survival, although further research is needed. This report presents an overview of outdoor air pollutants, sources, and global levels, as well as a description of epidemiological evidence linking outdoor air pollution with cancer incidence and mortality. Biological mechanisms of air pollution-derived carcinogenesis are also described. This report concludes by summarizing public health/policy recommendations, including multilevel interventions aimed at individual, community, and regional scales. Specific roles for medical and health care communities with regard to prevention and advocacy and recommendations for further research are also described.

Particulate matter exposure disturbs inflammatory cytokine homeostasis associated with changes in trace metal levels in mouse organs

Few studies have focused on the impact of particulate matter (PM) exposure with respect to the relationship between PM-induced inflammation and the levels of trace metals in tissues and organs. In this study, C57BL/6 male mice were exposed to ambient air alongside control mice breathing air filtered through a high-efficiency particulate air (HEPA) filter. In both groups, mRNA levels of pro- and anti-inflammatory cytokines were measured after 4, 8 and 12 weeks together with the trace metal contents of the lungs, heart, liver, hippocampus and blood. PM exposure resulted in a general upward trend in the levels of pro-inflammatory cytokines in lung, heart, liver and hippocampus. By contrast, IL-10 mRNA expression varied depending on the organ, with a continuous upward trend in heart and liver and an up-regulation at 8 weeks followed by a down-regulation at 12 weeks in lung and hippocampus. The disturbed homeostasis of inflammatory cytokines was accompanied by changes in trace metal levels in the mice. These alterations may have constituted a compensatory effect conferring protection from inflammatory damage. However, prolonged PM exposure finally resulted in the deficiency of several essential trace metals in the lungs and hippocampus, which may have contributed to the observed histological changes typical of an inflammatory response.

Applying landscape metrics and structural equation modeling to predict the effect of urban green space on air pollution and respiratory mortality in Tehran

Green space and its spatial formation are important elements of public welfare in urban environments and green ecosystems in big cities largely contribute to the mental and physical health of citizens. Tehran is Iran's biggest and most polluted city and air pollution in this city causes loss of human lives due to respiratory diseases. The effect of green area has been less studied in former researches in Tehran, and the reducing effects of green landscape on the mortality of respiratory diseases have not yet been evaluated. To measure the effects of green area landscape patterns (fragmentation, area-edge, shape, and aggregation) on public health, the current study evaluated the pathways and effects of green space on air pollution and the mortality of respiratory diseases using structural equation modeling approach and the partial least squares method. The results of the study indicated green space has a significant mitigating effect on air pollution and mortality of respiratory diseases and also air pollution has a meaningful increasing effect on mortality due to respiratory diseases in Tehran. The most important latent variable in green space is class area that indicates more area of green space is correlated with less mortality of respiratory diseases. The most important indicator of air pollution was the PM_2.5 that needs to be considered and controlled by urban policymakers. Accordingly, maximizing the green area and its cohesion and minimizing fragmentation and green patch edge can contribute to a reduction in air pollution and consequently lower mortality of citizens.