Time to harmonize national ambient air quality standards

The World Health Organization has developed ambient air quality guidelines at levels considered to be safe or of acceptable risk for human health. These guidelines are meant to support governments in defining national standards. It is unclear how they are followed.; We compiled an inventory of ambient air quality standards for 194 countries worldwide for six air pollutants: PM2.5, PM10, ozone, nitrogen dioxide, sulphur dioxide and carbon monoxide. We conducted literature and internet searches and asked country representatives about national ambient air quality standards.; We found information on 170 countries including 57 countries that did not set any air quality standards. Levels varied greatly by country and by pollutant. Ambient air quality standards for PM2.5, PM10 and SO2 poorly complied with WHO guideline values. The agreement was higher for CO, SO2 (10-min averaging time) and NO2.; Regulatory differences mirror the differences in air quality and the related burden of disease around the globe. Governments worldwide should adopt science based air quality standards and clean air management plans to continuously improve air quality locally, nationally, and globally

Long-Term Exposure to Traffic-Related Air Pollution and Diabetes: A Systematic Review and Meta-Analysis

Objectives: We report results of a systematic review on the health effects of long-term traffic-related air pollution (TRAP) and diabetes in the adult population.Methods: An expert Panel appointed by the Health Effects Institute conducted this systematic review. We searched the PubMed and LUDOK databases for epidemiological studies from 1980 to July 2019. TRAP was defined based on a comprehensive protocol. Random-effects meta-analyses were performed. Confidence assessments were based on a modified Office for Health Assessment and Translation (OHAT) approach, complemented with a broader narrative synthesis. We extended our interpretation to include evidence published up to May 2022.Results: We considered 21 studies on diabetes. All meta-analytic estimates indicated higher diabetes risks with higher exposure. Exposure to NO2 was associated with higher diabetes prevalence (RR 1.09; 95% CI: 1.02; 1.17 per 10 μg/m3), but less pronounced for diabetes incidence (RR 1.04; 95% CI: 0.96; 1.13 per 10 μg/m3). The overall confidence in the evidence was rated moderate, strengthened by the addition of 5 recently published studies.Conclusion: There was moderate evidence for an association of long-term TRAP exposure with diabetes

Health effects of ultrafine particles: a systematic literature review update of epidemiological evidence

Due to their small size, ultrafine particles (UFP) are believed to exert higher toxicity than larger particles. As numerous studies on health effects of UFP have been published since the last systematic review in 2013, we aim to systematically review the new literature.; We searched MEDLINE and the specialized LUDOK database for studies published between 01.01.2011 and 11.05.2017 investigating health effects of ambient air pollution-related UFP. We included epidemiologic studies containing UFP measures and quantifiable measures of associations. Relevant data were extracted on the basis of previously developed evaluation criteria.; We identified 85 original studies, conducting short-term (n = 75) and long-term (n = 10) investigations. Panel (n = 32), scripted exposure with predefined settings (n = 16) or time series studies (n = 11) were most frequent. Thirty-four studies adjusted for at least one other pollutant. Most consistent associations were identified for short-term effects on pulmonary/systemic inflammation, heart rate variability and blood pressure.; The evidence suggests adverse short-term associations with inflammatory and cardiovascular changes, which may be at least partly independent of other pollutants. For the other studied health outcomes, the evidence on independent health effects of UFP remains inconclusive or insufficient

Short-term association between ambient air pollution and pneumonia in children: a systematic review and meta-analysis of time-series and case-crossover studies

Ambient air pollution has been associated with respiratory diseases in children. However, its effects on pediatric pneumonia have not been meta-analyzed. We conducted a systematic review and meta-analysis of the short-term association between ambient air pollution and hospitalization of children due to pneumonia. We searched the Web of Science and PubMed for indexed publications up to January 2017. Pollutant-specific excess risk percentage (ER%) and confidence intervals (CI) were estimated using random effect models for particulate matter (PM) with diameter ≤ 10 (PM10) and ≤2.5 μm (PM2.5), sulfur dioxide (SO2), ozone (O3), nitrogen dioxide (NO2), and carbon monoxide (CO). Results were further stratified by subgroups (children under five, emergency visits versus hospital admissions, income level of study location, and exposure period). Seventeen studies were included in the meta-analysis. The ER% per 10 μg/m(3) increase of pollutants was 1.5% (95% CI: 0.6%-2.4%) for PM10 and 1.8% (95% CI: 0.5%-3.1%) for PM2.5. The corresponding values per 10 ppb increment of gaseous pollutants were 2.9% (95% CI: 0.4%-5.3%) for SO2, 1.7% (95% CI: 0.5%-2.8%) for O3, and 1.4% (95% CI: 0.4%-2.4%) for NO2. ER% per 1000 ppb increment of CO was 0.9% (95% CI: 0.0%-1.9%). Associations were not substantially different between subgroups. This meta-analysis shows a positive association between daily levels of ambient air pollution markers and hospitalization of children due to pneumonia. However, lack of studies from low-and middle-income countries limits the quantitative generalizability given that susceptibilities to the adverse effects of air pollution may be different in those populations. The meta-regression in our analysis further demonstrated a strong effect of country income level on heterogeneity

Comparing the lung cancer burden of ambient particulate matter using scenarios of air quality standards versus acceptable risk levels

Objectives Ambient particulate matter (PM) is regulated with science-based air quality standards, whereas carcinogens are regulated with a number of “acceptable” cases. Given that PM is also carcinogenic, we identify differences between approaches. Methods We assessed the lung cancer deaths for Switzerland attributable to exposure to PM up to 10 µm (PM10) and to five particle-bound carcinogens. For PM10, we used an epidemiological approach based on relative risks with four exposure scenarios compared to two counterfactual concentrations. For carcinogens, we used a toxicological approach based on unit risks with four exposure scenarios. Results The lung cancer burden using concentrations from 2010 was 10–14 times larger for PM10 than for the five carcinogens. However, the burden depends on the underlying exposure scenarios, counterfactual concentrations and number of carcinogens. All scenarios of the toxicological approach for five carcinogens result in a lower burden than the epidemiological approach for PM10. Conclusions Air quality standards—promoted so far by the WHO Air Quality Guidelines—provide a more appealing framework to guide health risk-oriented clean air policymaking than frameworks based on a number of “acceptable” cases

Comparing the lung cancer burden of ambient particulate matter using scenarios of air quality standards versus acceptable risk levels

Ambient particulate matter (PM) is regulated with science-based air quality standards, whereas carcinogens are regulated with a number of "acceptable" cases. Given that PM is also carcinogenic, we identify differences between approaches.; We assessed the lung cancer deaths for Switzerland attributable to exposure to PM up to 10 µm (PM; 10; ) and to five particle-bound carcinogens. For PM; 10; , we used an epidemiological approach based on relative risks with four exposure scenarios compared to two counterfactual concentrations. For carcinogens, we used a toxicological approach based on unit risks with four exposure scenarios.; The lung cancer burden using concentrations from 2010 was 10-14 times larger for PM; 10; than for the five carcinogens. However, the burden depends on the underlying exposure scenarios, counterfactual concentrations and number of carcinogens. All scenarios of the toxicological approach for five carcinogens result in a lower burden than the epidemiological approach for PM; 10; .; Air quality standards-promoted so far by the WHO Air Quality Guidelines-provide a more appealing framework to guide health risk-oriented clean air policymaking than frameworks based on a number of "acceptable" cases

Long-Term Exposure to Traffic-Related Air Pollution and Diabetes: A Systematic Review and Meta-Analysis.

Objectives: We report results of a systematic review on the health effects of long-term traffic-related air pollution (TRAP) and diabetes in the adult population. Methods: An expert Panel appointed by the Health Effects Institute conducted this systematic review. We searched the PubMed and LUDOK databases for epidemiological studies from 1980 to July 2019. TRAP was defined based on a comprehensive protocol. Random-effects meta-analyses were performed. Confidence assessments were based on a modified Office for Health Assessment and Translation (OHAT) approach, complemented with a broader narrative synthesis. We extended our interpretation to include evidence published up to May 2022. Results: We considered 21 studies on diabetes. All meta-analytic estimates indicated higher diabetes risks with higher exposure. Exposure to NO2 was associated with higher diabetes prevalence (RR 1.09; 95% CI: 1.02; 1.17 per 10 μg/m3), but less pronounced for diabetes incidence (RR 1.04; 95% CI: 0.96; 1.13 per 10 μg/m3). The overall confidence in the evidence was rated moderate, strengthened by the addition of 5 recently published studies. Conclusion: There was moderate evidence for an association of long-term TRAP exposure with diabetes