The role of burden of disease assessment in tracking progress towards achieving WHO global air quality guidelines.

OBJECTIVES: More than 90% of the global population live in areas exceeding the PM2.5 air quality guidelines (AQGs). We provide an overview of the ambient PM2.5-related burden of disease (BoD) studies along with scenario analysis in the framework of the WHO AQG update on the estimated reduction in the BoD if AQGs were achieved globally. METHODS: We reviewed the literature for large-scale studies for the BoD attributed to ambient PM2.5. Moreover, we used the latest WHO statistics to calculate the BoD at current levels and the scenarios of aligning with interim targets and AQG levels. RESULTS: The most recent BoD studies (2010 onwards) share a similar methodology, but there are differences in the input data which affect the estimates for attributable deaths (2.9-8.9 million deaths annually). Moreover, we found that if AQGs were achieved, the estimated BoD would be reduced by up to 50% in total deaths worldwide. CONCLUSIONS: Understanding the BoD across countries, especially in those that do not align with the AQGs, is essential in order to inform actions to reduce air pollution globally.

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.

Health impact and related cost of ambient air pollution in Tehran.

Ambient air pollution represents one of the biggest environmental risks to health. In this study, we estimated the avoidable mortality burden attributable to ambient air pollution in Tehran, and derived the economic impact associated with these health effects. Using PM2.5 data from ground-level air pollution measurements in Tehran, we estimated PM2.5 exposure for 349 neighborhoods in Tehran, by the Environmental Benefits Mapping and Analysis Program (BenMAP-CE). We considered five scenarios related to PM2.5 levels: an increase to 35 µg/m3; a reduction to 25 µg/m3; a reduction to 15 µg/m3; a reduction to 10 µg/m3 (the WHO's air quality guideline value); and a full roll-back, assuming a reduction to 2.4 µg/m3. All scenarios used 2017 p.m.2.5 levels as a starting point. Using the concentration response function of the Global Exposure Mortality Model (GEMM), we estimated a total of 7146 (95% CI: 6596-7513) adult (age ≥25 years) deaths attributable to PM2.5 in 2017. The leading causes of death were ischemic heart disease (3437; 95% CI: 3315-3516), stroke (886; 95% CI: 693-1002), lower respiratory infections (531: 95% CI: 414-589), chronic obstructive pulmonary disease (364; 95% CI: 271-420), and lung cancer (274; 95% CI: 236-298). The estimated total annual economic benefit (2017) of reducing PM2.5 concentration levels to 2.4 µg/m3 was USD 0.591 (95% CI: 0.447-0.624) billion per year, using the value of a life year (VOLY) approach, and USD 2.894 (95% CI: 2.671-3.043) billion per year, using the value of a statistical life (VSL) approach.

The Role of Socioeconomic Status in the Association of Lung Function and Air Pollution-A Pooled Analysis of Three Adult ESCAPE Cohorts.

Ambient air pollution is a leading environmental risk factor and its broad spectrum of adverse health effects includes a decrease in lung function. Socioeconomic status (SES) is known to be associated with both air pollution exposure and respiratory function. This study assesses the role of SES either as confounder or effect modifier of the association between ambient air pollution and lung function. Cross-sectional data from three European multicenter adult cohorts were pooled to assess factors associated with lung function, including annual means of home outdoor NO2. Pre-bronchodilator lung function was measured according to the ATS-criteria. Multiple mixed linear models with random intercepts for study areas were used. Three different factors (education, occupation and neighborhood unemployment rate) were considered to represent SES. NO2 exposure was negatively associated with lung function. Occupation and neighborhood unemployment rates were not associated with lung function. However, the inclusion of the SES-variable education improved the models and the air pollution-lung function associations got slightly stronger. NO2 associations with lung function were not substantially modified by SES-variables. In this multicenter European study we could show that SES plays a role as a confounder in the association of ambient NO2 exposure with lung function.

Costs of coronary heart disease and mortality associated with near-roadway air pollution.

BACKGROUND: Emerging evidence indicates that the near-roadway air pollution (NRAP) mixture contributes to CHD, yet few studies have evaluated the associated costs. OBJECTIVE: We integrated an assessment of NRAP-attributable CHD in Southern California with new methods to value the associated mortality and hospitalizations. METHODS: Based on population-weighted residential exposure to NRAP (traffic density, proximity to a major roadway and elemental carbon), we estimated the inflation-adjusted value of NRAP-attributable mortality and costs of hospitalizations that occurred in 2008. We also estimated anticipated costs in 2035 based on projected changes in population and in NRAP exposure associated with California's plans to reduce greenhouse gas emissions. For comparison, we estimated the value of CHD mortality attributable to PM less than 2.5µm in diameter (PM2.5) in both 2008 and 2035. RESULTS: The value of CHD mortality attributable to NRAP in 2008 was between $3.8 and $11.5 billion, 23% (major roadway proximity) to 68% (traffic density) of the $16.8 billion attributable to regulated regional PM2.5. NRAP-attributable costs were projected to increase to $10.6 to $22 billion in 2035, depending on the NRAP metric. Cost of NRAP-attributable hospitalizations for CHD in 2008 was $48.6 million and was projected to increase to $51.4 million in 2035. CONCLUSIONS: We developed an economic framework that can be used to estimate the benefits of regulations to improve air quality. CHD attributable to NRAP has a large economic impact that is expected to increase by 2035, largely due to an aging population. PM2.5-attributable costs may underestimate total value of air pollution-attributable CHD.

Health benefits of a reduction of PM10 and NO2 exposure after implementing a clean air plan in the Agglomeration Lausanne-Morges.

Exposure to urban air pollution has been associated with adverse effects on cardio-vascular and respiratory health, both short and long term. Consequently, governments have applied policies to reduce air pollution. Quantitative health impact assessments of hypothetic changes in air pollution have been conducted at national and global level, but assessments of observed air pollution changes associated with specific clean air policies at a local or regional scale remain scarce. This study estimates health impacts attributable to a decrease in PM10 and NO2 exposure in the Agglomeration of Lausanne-Morges (ALM), Switzerland, between 2005 and 2015, corresponding to the implementation period of a supra-municipal plan of measures to reduce air pollution in different sectors such as transport, energy, and industry (called Plan OPair 05). The health impact assessment compares health effects attributed to air pollution exposure levels in 2015 (reference case) with those in 2005 (counterfactual scenario), using 2015 as baseline for all other input data. In the ALM, the modeled PM10 exposure reduction of 3.3µg/m3 from 2005 to 2015 prevents 26 premature deaths (equivalent to around 290 years of life lost), 215 hospitalization days due to cardio-vascular and respiratory diseases as well as approximately 47,000 restricted activity days annually. Monetized health impacts of the reduction of PM10 exposure are valued at approximately CHF 36 million annually. Immaterial costs, mainly related to the economic valuation of years of life lost, dominate the monetized health impacts (90% of total value), while savings at the workplace (net loss in production and reoccupation costs) amount to about CHF 1.9 million, and savings in health care costs to about CHF 0.5 million. The assessment is sensitive to the value assigned to immaterial costs and to uncertainties in the relative risk estimates, whereas variations in the baseline year (i.e. using 2005 data instead of 2015 data) affect results to a much lower degree. The alternative calculation based on NO2 exposure, which dropped by 5.6µg/m3, suggests the prevention of 51 premature deaths (equivalent to around 550 years of life lost) overall impacts valued at CHF 49 million. All in all, the reduction in mortality due to the air quality improvements accounts for (depending on the considered pollutant) about 1% to 2% of total all-cause annual mortality in the ALM population or 4-8 times larger than the annual traffic fatalities in the ALM.

Health impact assessment of transport policies in Rotterdam: Decrease of total traffic and increase of electric car use.

BACKGROUND: Green house gas (GHG) mitigation policies can be evaluated by showing their co-benefits to health. METHOD: Health Impact Assessment (HIA) was used to quantify co-benefits of GHG mitigation policies in Rotterdam. The effects of two separate interventions (10% reduction of private vehicle kilometers and a share of 50% electric-powered private vehicle kilometers) on particulate matter (PM2.5), elemental carbon (EC) and noise (engine noise and tyre noise) were assessed using Years of Life Lost (YLL) and Years Lived with Disability (YLD). The baseline was 2010 and the end of the assessment 2020. RESULTS: The intervention aimed at reducing traffic is associated with a decreased exposure to noise resulting in a reduction of 21 (confidence interval (CI): 11-129) YLDs due to annoyance and 35 (CI: 20-51) YLDs due to sleep disturbance for the population per year. The effects of 50% electric-powered car use are slightly higher with a reduction of 26 (CI: 13-116) and 41 (CI: 24-60) YLDs, respectively. The two interventions have marginal effects on air pollution, because already implemented traffic policies will reduce PM2.5 and EC by around 40% and 60% respectively, from 2010 to 2020. DISCUSSION: The evaluation of planned interventions, related to climate change policies, targeting only the transport sector can result in small co-benefits for health, if the analysis is limited to air pollution and noise. This urges to expand the analysis by including other impacts, e.g. physical activity and well-being, as a necessary step to better understanding consequences of interventions and carefully orienting resources useful to build knowledge to improve public health.

The hidden economic burden of air pollution-related morbidity: evidence from the Aphekom project.

Public decision-makers commonly use health impact assessments (HIA) to quantify the impacts of various regulation policies. However, standard HIAs do not consider that chronic diseases (CDs) can be both caused and exacerbated by a common factor, and generally focus on exacerbations. As an illustration, exposure to near road traffic-related pollution (NRTP) may affect the onset of CDs, and general ambient or urban background air pollution (BP) may exacerbate these CDs. We propose a comprehensive HIA that explicitly accounts for both the acute effects and the long-term effects, making it possible to compute the overall burden of disease attributable to air pollution. A case study applies the two HIA methods to two CDs-asthma in children and coronary heart disease (CHD) in adults over 65-for ten European cities, totaling 1.89 million 0-17-year-old children and 1.85 million adults aged 65 and over. We compare the current health effects with those that might, hypothetically, be obtained if exposure to NRTP was equally low for those living close to busy roads as it is for those living farther away, and if annual mean concentrations of both PM10 and NO2-taken as markers of general urban air pollution-were no higher than 20 µg/m3. Returning an assessment of € 0.55 million (95 % CI 0-0.95), the HIA based on acute effects alone accounts for only about 6.2 % of the annual hospitalization burden computed with the comprehensive method [€ 8.81 million (95 % CI 3-14.4)], and for about 0.15 % of the overall economic burden of air pollution-related CDs [€ 370 million (95 % CI 106-592)]. Morbidity effects thus impact the health system more directly and strongly than previously believed. These findings may clarify the full extent of benefits from any public health or environmental policy involving CDs due to and exacerbated by a common factor.

Building-related health impacts in European and Chinese cities: a scalable assessment method.

BACKGROUND: Public health is often affected by societal decisions that are not primarily about health. Climate change mitigation requires intensive actions to minimise greenhouse gas emissions in the future. Many of these actions take place in cities due to their traffic, buildings, and energy consumption. Active climate mitigation policies will also, aside of their long term global impacts, have short term local impacts, both positive and negative, on public health. Our main objective was to develop a generic open impact model to estimate health impacts of emissions due to heat and power consumption of buildings. In addition, the model should be usable for policy comparisons by non-health experts on city level with city-specific data, it should give guidance on the particular climate mitigation questions but at the same time increase understanding on the related health impacts and the model should follow the building stock in time, make comparisons between scenarios, propagate uncertainties, and scale to different levels of detail. We tested The functionalities of the model in two case cities, namely Kuopio and Basel. We estimated the health and climate impacts of two actual policies planned or implemented in the cities. The assessed policies were replacement of peat with wood chips in co-generation of district heat and power, and improved energy efficiency of buildings achieved by renovations. RESULTS: Health impacts were not large in the two cities, but also clear differences in implementation and predictability between the two tested policies were seen. Renovation policies can improve the energy efficiency of buildings and reduce greenhouse gas emissions significantly, but this requires systematic policy sustained for decades. In contrast, fuel changes in large district heating facilities may have rapid and large impacts on emissions. However, the life cycle impacts of different fuels is somewhat an open question. CONCLUSIONS: In conclusion, we were able to develop a practical model for city-level assessments promoting evidence-based policy in general and health aspects in particular. Although all data and code is freely available, implementation of the current model version in a new city requires some modelling skills.

Reduce air pollution to reduce the burden of cardiovascular diseases!

The second highest environmental risk factor for years of lives lost annually.

Years of life lost and morbidity cases attributable to transportation noise and air pollution: A comparative health risk assessment for Switzerland in 2010.

BACKGROUND: There is growing evidence that chronic exposure to transportation related noise and air pollution affects human health. However, health burden to a country of these two pollutants have been rarely compared. AIMS: As an input for external cost quantification, we estimated the cardiorespiratory health burden from transportation related noise and air pollution in Switzerland, incorporating the most recent findings related to the health effects of noise. METHODS: Spatially resolved noise and air pollution models for the year 2010 were derived for road, rail and aircraft sources. Average day-evening-night sound level (Lden) and particulate matter (PM10) were selected as indicators, and population-weighted exposures derived by transportation source. Cause-specific exposure-response functions were derived from a meta-analysis for noise and literature review for PM10. Years of life lost (YLL) were calculated using life table methods; population attributable fraction was used for deriving attributable cases for hospitalisations, respiratory illnesses, visits to general practitioners and restricted activity days. RESULTS: The mean population weighted exposure above a threshold of 48dB(A) was 8.74dB(A), 1.89dB(A) and 0.37dB(A) for road, rail and aircraft noise. Corresponding mean exposure contributions were 4.4, 0.54, 0.12µg/m(3) for PM10. We estimated that in 2010 in Switzerland transportation caused 6000 and 14,000 YLL from noise and air pollution exposure, respectively. While there were a total of 8700 cardiorespiratory hospital days attributed to air pollution exposure, estimated burden due to noise alone amounted to 22,500 hospital days. CONCLUSIONS: YLL due to transportation related pollution in Switzerland is dominated by air pollution from road traffic, whereas consequences for morbidity and indicators of quality of life are dominated by noise. In terms of total external costs the burden of noise equals that of air pollution.

Quantifying the health impacts of ambient air pollutants: recommendations of a WHO/Europe project.

OBJECTIVE: Quantitative estimates of air pollution health impacts have become an increasingly critical input to policy decisions. The WHO project "Health risks of air pollution in Europe--HRAPIE" was implemented to provide the evidence-based concentration-response functions for quantifying air pollution health impacts to support the 2013 revision of the air quality policy for the European Union (EU). METHODS: A group of experts convened by WHO Regional Office for Europe reviewed the accumulated primary research evidence together with some commissioned reviews and recommended concentration-response functions for air pollutant-health outcome pairs for which there was sufficient evidence for a causal association. RESULTS: The concentration-response functions link several indicators of mortality and morbidity with short- and long-term exposure to particulate matter, ozone and nitrogen dioxide. The project also provides guidance on the use of these functions and associated baseline health information in the cost-benefit analysis. CONCLUSIONS: The project results provide the scientific basis for formulating policy actions to improve air quality and thereby reduce the burden of disease associated with air pollution in Europe.

Cost of near-roadway and regional air pollution-attributable childhood asthma in Los Angeles County.

BACKGROUND: Emerging evidence suggests that near-roadway air pollution (NRP) exposure causes childhood asthma. The associated costs are not well documented. OBJECTIVE: We estimated the cost of childhood asthma attributable to residential NRP exposure and regional ozone (O3) and nitrogen dioxide (NO2) levels in Los Angeles County. We developed a novel approach to apportion the costs between these exposures under different pollution scenarios. METHODS: We integrated results from a study of willingness to pay to reduce the burden of asthma with results from studies of health care use and charges to estimate the costs of an asthma case and exacerbation. We applied those costs to the number of asthma cases and exacerbations caused by regional pollution in 2007 and to hypothetical scenarios of a 20% reduction in regional pollution in combination with a 20% reduction or increase in the proportion of the total population living within 75 m of a major roadway. RESULTS: Cost of air pollution-related asthma in Los Angeles County in 2007 was $441 million for O3 and $202 million for NO2 in 2010 dollars. Cost of routine care (care in absence of exacerbation) accounted for 18% of the combined NRP and O3 cost and 39% of the combined NRP and NO2 cost; these costs were not recognized in previous analyses. NRP-attributable asthma accounted for 43% (O3) to 51% (NO2) of the total annual cost of exacerbations and routine care associated with pollution. Hypothetical scenarios showed that costs from increased NRP exposure might offset savings from reduced regional pollution. CONCLUSIONS: Our model disaggregates the costs of regional pollution and NRP exposure and illustrates how they might vary under alternative exposure scenarios. The cost of air pollution is a substantial burden on families and an economic loss for society.

Costs of childhood asthma due to traffic-related pollution in two California communities.

Recent research suggests the burden of childhood asthma that is attributable to air pollution has been underestimated in traditional risk assessments, and there are no estimates of these associated costs. We aimed to estimate the yearly childhood asthma-related costs attributable to air pollution for Riverside and Long Beach, CA, USA, including: 1) the indirect and direct costs of healthcare utilisation due to asthma exacerbations linked with traffic-related pollution (TRP); and 2) the costs of health care for asthma cases attributable to local TRP exposure. We calculated costs using estimates from peer-reviewed literature and the authors' analysis of surveys (Medical Expenditure Panel Survey, California Health Interview Survey, National Household Travel Survey, and Health Care Utilization Project). A lower-bound estimate of the asthma burden attributable to air pollution was US$18 million yearly. Asthma cases attributable to TRP exposure accounted for almost half of this cost. The cost of bronchitic episodes was a major proportion of both the annual cost of asthma cases attributable to TRP and of pollution-linked exacerbations. Traditional risk assessment methods underestimate both the burden of disease and cost of asthma associated with air pollution, and these costs are borne disproportionately by communities with higher than average TRP.

Prevention--a cost-effective way to fight the non-communicable disease epidemic: an academic perspective of the United Nations High-level NCD Meeting.

The United Nations General Assembly has convened a Summit on non-communicable diseases (NCDs), an historic moment in the global combat of these disorders. Lifestyles in increasingly urban and globalised environments have led to a steep surge in NCD incidence in low and middle income countries, where two thirds of all NCD deaths occur (most importantly from cancer, cardiovascular and respiratory disease as well as diabetes). Treatment of NCDs is usually long term and expensive, thus threatening patients' and nations' budgets and putting them at high risk for poverty. The NCD Summit offers an opportunity for strengthening and shaping primary prevention, the most cost-effective instrument to fight major risk factors such as tobacco smoking, alcohol abuse, physical inactivity and unhealthy diet. From a Swiss perspective, we also emphasised the efforts for new laws on prevention and diagnosis registration, in accordance with the recommendations of the NCD summit in order to strengthen primary prevention and disease monitoring. In addition, the need for structural prevention across all policy sectors with leadership in environmental policy making to prevent NCDs as well as the need to adapt and strengthen primary health care are equally relevant for Switzerland. To compliment efforts in primary prevention, the field of NCDs requires special R&D platforms for affordable NCD drugs and diagnostics for neglected population segments in both Switzerland and low and middle income countries. Switzerland has a track record in research and development against diseases of poverty on a global scale that now needs to be applied to NCDs.

Public health importance of triggers of myocardial infarction: a comparative risk assessment.

BACKGROUND: Acute myocardial infarction is triggered by various factors, such as physical exertion, stressful events, heavy meals, or increases in air pollution. However, the importance and relevance of each trigger are uncertain. We compared triggers of myocardial infarction at an individual and population level. METHODS: We searched PubMed and the Web of Science citation databases to identify studies of triggers of non-fatal myocardial infarction to calculate population attributable fractions (PAF). When feasible, we did a meta-regression analysis for studies of the same trigger. FINDINGS: Of the epidemiologic studies reviewed, 36 provided sufficient details to be considered. In the studied populations, the exposure prevalence for triggers in the relevant control time window ranged from 0.04% for cocaine use to 100% for air pollution. The reported odds ratios (OR) ranged from 1.05 to 23.7. Ranking triggers from the highest to the lowest OR resulted in the following order: use of cocaine, heavy meal, smoking of marijuana, negative emotions, physical exertion, positive emotions, anger, sexual activity, traffic exposure, respiratory infections, coffee consumption, air pollution (based on a difference of 30 µg/m3 in particulate matter with a diameter <10 µm [PM10]). Taking into account the OR and the prevalences of exposure, the highest PAF was estimated for traffic exposure (7.4%), followed by physical exertion (6.2%), alcohol (5.0%), coffee (5.0%), a difference of 30 µg/m3 in PM10 (4.8%), negative emotions (3.9%), anger (3.1%), heavy meal (2.7%), positive emotions (2.4%), sexual activity (2.2%), cocaine use (0.9%), marijuana smoking (0.8%) and respiratory infections (0.6%). Interpretation In view of both the magnitude of the risk and the prevalence in the population, air pollution is an important trigger of myocardial infarction, it is of similar magnitude (PAF 5-7%) as other well accepted triggers such as physical exertion, alcohol, and coffee. Our work shows that ever-present small risks might have considerable public health relevance. FUNDING: The research on air pollution and health at Hasselt University is supported by a grant from the Flemish Scientific Fund (FWO, Krediet aan navorsers/G.0873.11), tUL-impulse financing, and bijzonder onderzoeksfonds (BOF) and at the Katholieke Universiteit Leuven by the sustainable development programme of BELSPO (Belgian Science Policy).