Potential health impacts of changes in air pollution exposure associated with moving traffic into a road tunnel

Near-Source Risk Functions for Particulate Matter Are Critical When Assessing the Health Benefits of Local Abatement Strategies

When mortality or other health outcomes attributable to fine particulate matter (PM2.5) are estimated, the same exposure-response function (ERF) is usually assumed regardless of the source and composition of the particles, and independently of the spatial resolution applied in the exposure model. While several recent publications indicate that ERFs based on exposure models resolving within-city gradients are steeper per concentration unit (μgm-3), the ERF for PM2.5 recommended by the World Health Organization does not reflect this observation and is heavily influenced by studies based on between-city exposure estimates. We evaluated the potential health benefits of three air pollution abatement strategies: electrification of light vehicles, reduced use of studded tires, and introduction of congestion charges in Stockholm and Gothenburg, using different ERFs. We demonstrated that using a single ERF for PM2.5 likely results in an underestimation of the effect of local measures and may be misleading when evaluating abatement strategies. We also suggest applying ERFs that distinguish between near-source and regional contributions of exposure to PM2.5. If separate ERFs are applied for near-source and regional PM2.5, congestion charges as well as a reduction of studded tire use are estimated to be associated with a significant reduction in the mortality burden in both Gothenburg and Stockholm. In some scenarios the number of premature deaths is more than 10 times higher using separate ERFs in comparison to using a single ERF irrespective of sources as recommended by the WHO. For electrification, the net change in attributable deaths is small or within the uncertainty range depending on the choice of ERF.

Respiratory Hospitalizations and Their Relationship with Air Pollution Sources in the Period of FIFA World Cup and Olympic Games in Rio de Janeiro, Brazil

Background: From 2010 onwards, the city of Rio de Janeiro has undergone changes related to the 2014 FIFA World Cup and the 2016 Olympic Games, potentially affecting the respiratory health of inhabitants. Thus, the spatial distribution of respiratory hospitalizations (2008–2017) and the relationship between this outcome and potential air pollution sources in the city of Rio de Janeiro (2013–2017) were evaluated. Methods: An ecological study was performed using the Bayesian model with multivariate Poisson regression for the period of the sporting events (2013–2017). The outcome was the ratio of hospitalizations for respiratory diseases by the population at risk. Data analysis was performed in the total population and by sex and age group. The air pollution-related variables included industrial districts, traffic density, tunnel portals, a seaport, airports, and construction/road work. Results: All explanatory variables, except tunnel portals, were associated with an increase in the outcome. Construction/road work showed a greater magnitude of association than the other pollution-related variables. Airports were associated with an increased hospitalization ratio among the ≥60 year-old group (mean = 2.46, 95% credible intervals = 1.35–4.46). Conclusion: This study allows for a better understanding of the geographical distribution of respiratory problems in the city of Rio de Janeiro. Present results may contribute to improved healthcare planning and raise hypotheses concerning exposure to air pollution and respiratory hospitalizations.

Exterior air quality monitoring for the Eurasia Tunnel in Istanbul, Turkey

Traffic is a major concern for the city of Istanbul due to the rapid increase in population and car ownership. Eurasia Tunnel, which has a capacity around 100,000 light vehicles/day, is the fourth highway link between Asia and Europe, established to relieve the existing pressure on the transport system. As an important alternative to other Bosphorus Strait crossings, the tunnel offers directly reduced traffic durations in the city especially during rush hours and indirectly provides reduced fuel consumption, thereby less harmful gas emissions into the atmosphere. The main objective of this study is to evaluate the air quality effects of the Eurasia Tunnel on the city of Istanbul through investigating the air quality 1 year before and 2 years after operation, and comparing the hourly and daily pollutant levels with tunnel traffic. Monitoring data were examined to detect the relationships between selected pollutant concentrations, to evaluate meteorology effects on the pollutants and to identify air quality impact of the Eurasia Tunnel. Analyses revealed that air pollutants concentrations do not increase with increase in tunnel traffic. Moreover, since the tunnel entered operation, average hourly CO, PM₁₀ and PM_2.5 concentrations at monitoring stations located close to the stacks have decreased 16-30%, 44-46% and 12-24%, respectively. Average NO₂ concentrations increased about 9-24%, but these concentrations still remain below the 1-hour standard. All in all, Eurasia Tunnel has no significant effect on the Istanbul's air quality.

Air quality impact assessment for the Eurasia Tunnel in Istanbul, Turkey

The Eurasia Tunnel, a 5.4-km tunnel connecting the Asian and European sides of Istanbul, Turkey, was opened for operation in December 2016. This paper describes the air quality modeling that was conducted during the design phase of the structure, to evaluate the impact of the tunnel traffic on ambient air quality in the vicinity of the tunnel. The ventilation of the tunnel consists of longitudinal forced ventilation with vertical extraction through two stacks located near the Asian and European portals of the tunnel. The analysis was conducted using the AERMOD computer program for three pollutants CO, NO₂, and PM₁₀. Model results show that pollutants will rapidly disperse once released from the stack and will not affect air quality in the vicinity of the tunnel. The most critical parameters which controlled the ventilation system design were found to be NO₂ and PM₁₀. Maximum concentrations are not expected to violate the pertinent Turkish and EU air quality standards. Overall, this analysis shows that the ventilation system is efficient for the dispersion of the pollutants.

New functional pavements for pedestrians and cyclists

When many fields of pedestrian and cyclist safety have been extensively studied, the surfacing has long been left unquestioned, despite being developed for another mode of transport and being one of the main causes for falls and fall injuries. In this project new surfacing materials for pedestrian and cyclist safety have been produced. Focusing on augmenting previously largely disregarded parameters as impact absorption, comfort and visibility at the same time as avoiding deteriorating of crucial parameters as friction and wear resistance. Rubber content, binder type, and pigment addition have been varied and evaluated. The results demonstrate that by increasing rubber content of the mixtures the head injury criterion (HIC) value and injury risk can be decreased while maintaining frictional properties according to existing criteria. Assembly of test-lanes demonstrate that some developed materials experience lower flow and component separation than standard materials due to rubber addition, calling for further optimisation of construction procedure linked to content development. Initial trials on the test-lanes indicate that a polyurethane (PU) based material has high cycling comfort, visibility and can be modified with phosphorescence properties. For standard asphalt, impact absorption might be inflicted by modification of bitumen alone but is mostly augmented by rubber addition. The results also indicate that rubber content can decrease ice formation on the materials.

Health Impact of PM10, PM2.5 and Black Carbon Exposure Due to Different Source Sectors in Stockholm, Gothenburg and Umea, Sweden

The most important anthropogenic sources of primary particulate matter (PM) in ambient air in Europe are exhaust and non-exhaust emissions from road traffic and combustion of solid biomass. There is convincing evidence that PM, almost regardless of source, has detrimental health effects. An important issue in health impact assessments is what metric, indicator and exposure-response function to use for different types of PM. The aim of this study is to describe sectorial contributions to PM exposure and related premature mortality for three Swedish cities: Gothenburg, Stockholm and Umea. Exposure is calculated with high spatial resolution using atmospheric dispersion models. Attributed premature mortality is calculated separately for the main local sources and the contribution from long-range transport (LRT), applying different relative risks. In general, the main part of the exposure is due to LRT, while for black carbon, the local sources are equally or more important. The major part of the premature deaths is in our assessment related to local emissions, with road traffic and residential wood combustion having the largest impact. This emphasizes the importance to resolve within-city concentration gradients when assessing exposure. It also implies that control actions on local PM emissions have a strong potential in abatement strategies.

Impacts on air pollution and health by changing commuting from car to bicycle

Our study is based on individual data on people's home and work addresses, as well as their age, sex and physical capacity, in order to establish realistic bicycle-travel distances. A transport model is used to single out data on commuting preferences in the County Stockholm. Our analysis shows there is a very large potential for reducing emissions and exposure if all car drivers living within a distance corresponding to a maximum of a 30min bicycle ride to work would change to commuting by bicycle. It would result in >111,000 new cyclists, corresponding to an increase of 209% compared to the current situation. Mean population exposure would be reduced by about 7% for both NO_x and black carbon (BC) in the most densely populated area of the inner city of Stockholm. Applying a relative risk for NO_x of 8% decrease in all-cause mortality associated with a 10μgm^-3 decrease in NO_x, this corresponds to >449 (95% CI: 340-558) years of life saved annually for the Stockholm county area with 2.1 million inhabitants. This is more than double the effect of the reduced mortality estimated for the introduction of congestion charge in Stockholm in 2006. Using NO₂ or BC as indicator of health impacts, we obtain 395 (95% CI: 172-617) and 185 (95% CI: 158-209) years of life saved for the population, respectively. The calculated exposure of BC and its corresponding impacts on mortality are likely underestimated. With this in mind the estimates using NO_x, NO₂ and BC show quite similar health impacts considering the 95% confidence intervals.

Health Impact Assessment of a Predicted Air Quality Change by Moving Traffic from an Urban Ring Road into a Tunnel. The Case of Antwerp, Belgium

Background

The Antwerp ring road has a traffic density of 300,000 vehicles per day and borders the city center. The ‘Ringland project’ aims to change the current ‘open air ring road’ into a ‘filtered tunneled ring road’, putting the entire urban ring road into a tunnel and thus filtering air pollution. We conducted a health impact assessment (HIA) to quantify the possible benefit of a ‘filtered tunneled ring road’, as compared to the ‘open air ring road’ scenario, on air quality and its long-term health effects.

Materials and Methods

We modeled the change in annual ambient PM_2.5 and NO₂ concentrations by covering 15 kilometers of the Antwerp ring road in high resolution grids using the RIO-IFDM street canyon model. The exposure-response coefficients used were derived from a literature review: all-cause mortality, life expectancy, cardiopulmonary diseases and childhood Forced Vital Capacity development (FVC).

Results

Our model predicts changes between -1.5 and +2 μg/m³ in PM_2.5 within a 1,500 meter radius around the ring road, for the ‘filtered tunneled ring road’ scenario as compared to an ‘open air ring road’. These estimated annual changes were plotted against the population exposed to these differences. The calculated change of PM_2.5 is associated with an expected annual decrease of 21 deaths (95% CI 7 to 41). This corresponds with 11.5 deaths avoided per 100,000 inhabitants (95% CI 3.9–23) in the first 500 meters around the ring road every year. Of 356 schools in a 1,500 meter perimeter around the ring road changes between -10 NO₂ and + 0.17 μg/m³ were found, corresponding to FVC improvement of between 3 and 64ml among school-age children. The predicted decline in lung cancer mortality and incidence of acute myocardial infarction were both only 0.1 per 100,000 inhabitants or less.

Conclusion

The expected change in PM_2,5 and NO₂ by covering the entire urban ring road in Antwerp is associated with considerable health gains for the approximate 352,000 inhabitants living in a 1,500 meter perimeter around the current open air ring road.