Haneen Khreis

Fifty Shades of Green: Pathway to Healthy Urban Living

Currently half the world population lives in cities, and this proportion is expected to increase rapidly to 70% over the next years. Over the years, we have created large, mostly grey cities with many high-rise buildings and little green space. Disease rates tend to be higher in urban areas than in rural areas. More green space in cities could reduce these rates. Here, we describe the importance of green space for health, and make recommendations for further research. Green space has been associated with many beneficial health effects, including reduced all-cause and cardiovascular mortality and improved mental health, possibly through mediators, such as reduced air pollution, temperature and stress, and increased physical activity, social contacts, and restoration. Additional studies are needed to strengthen the evidence base and provide further guidelines to transport planners, urban planners, and landscape architects. We need more longitudinal studies and intervention studies, further understanding of the contribution of various mechanisms toward health, and more information on susceptible populations and on where, when, how much, and what type of green space is needed. Also needed are standardized methods for green space quality assessments and evaluations of effectiveness of green prescriptions in clinical practice. Many questions are ideally suited for environmental epidemiologists, who should work with other stakeholders to address the right questions and translate knowledge into action. In conclusion, a growing evidence base supports the hypothesis that greener cities are healthier cities.

Car free cities: Pathway to healthy urban living

BACKGROUND Many cities across the world are beginning to shift their mobility solution away from the private cars and towards more environmentally friendly and citizen-focused means. Hamburg, Oslo, Helsinki, and Madrid have recently announced their plans to become (partly) private car free cities. Other cities like Paris, Milan, Chengdu, Masdar, Dublin, Brussels, Copenhagen, Bogota, and Hyderabad have measures that aim at reducing motorized traffic including implementing car free days, investing in cycling infrastructure and pedestrianization, restricting parking spaces and considerable increases in public transport provision. Such plans and measures are particularly implemented with the declared aim of reducing greenhouse gas emissions. These reductions are also likely to benefit public health. AIMS We aimed to describe the plans for private car free cities and its likely effects on public health. METHODS We reviewed the grey and scientific literature on plans for private car free cities, restricted car use, related exposures and health. RESULTS An increasing number of cities are planning to become (partly) private car free. They mainly focus on the reduction of private car use in city centers. The likely effects of such policies are significant reductions in traffic-related air pollution, noise, and temperature in city centers. For example, up to a 40% reduction in NO2 levels has been reported on car free days. These reductions are likely to lead to a reduction in premature mortality and morbidity. Furthermore the reduction in the number of cars, and therefore a reduction in the need for parking places and road space, provides opportunities to increase green space and green networks in cities, which in turn can lead to many beneficial health effects. All these measures are likely to lead to higher levels of active mobility and physical activity which may improve public health the most and also provide more opportunities for people to interact with each other in public space. Furthermore, such initiatives, if undertaken at a sufficiently large scale can result in positive distal effects and climate change mitigation through CO2 reductions. The potential negative effects which may arise due to motorized traffic detouring around car free zone into their destinations also need further evaluation and the areas in which car free zones are introduced need to be given sufficient attention so as not to become an additional way to exacerbate socioeconomic divides. The extent and magnitude of all the above effects is still unclear and needs further research, including full chain health impact assessment modeling to quantify the potential health benefits of such schemes, and exposure and epidemiological studies to measure any changes when such interventions take place. CONCLUSIONS The introduction of private car free cities is likely to have direct and indirect health benefits, but the exact magnitude and potential conflicting effects are as yet unclear. This paper has overviewed the expected health impacts, which can be useful to underpin policies to reduce car use in cities.

Participatory quantitative health impact assessment of urban and transport planning in cities: a review and research needs

INTRODUCTION Urban and transport planning have large impacts on public health, but these are generally not explicitly considered and/or quantified, partly because there are no comprehensive models, methods and tools readily available. Air pollution, noise, temperature, green space, motor vehicle crashes and physical activity are important pathways linking urban and transport planning and public health. For policy decision-making, it is important to understand and be able to quantify the full-chain from source through pathways to health effects and impacts to substantiate and effectively target actions. In this paper, we aim to provide an overview of recent studies on the health impacts related to urban and transport planning in cities, describe the need for novel participatory quantitative health impact assessments (HIA) and provide recommendations. METHOD To devise our searches and narrative, we were guided by a recent conceptual framework linking urban and transport planning, environmental exposures, behaviour and health. We searched PubMed, Web of Science, Science Direct, and references from relevant articles in English language from January 1, 1980, to November 1, 2016, using pre-defined search terms. RESULTS The number of HIA studies is increasing rapidly, but there is lack of participatory integrated and full-chain HIA models, methods and tools. These should be based on the use of a systemic multidisciplinary/multisectorial approach and state-of-the-art methods to address questions such as what are the best, most feasible and needed urban and transport planning policy measures to improve public health in cities? Active citizen support and new forms of communication between experts and citizens and the involvement of all major stakeholders are crucial to find and successfully implement health promoting policy measures. CONCLUSION We provided an overview of the current state-of-the art of HIA in cities and made recommendations for further work. The process on how to get there is as important and will provide answers to many crucial questions on e.g. how different disciplines can effectively work together, how to incorporate citizen and stakeholder opinion into quantitative HIA modelling for urban and transport planning, how different modelling and measurement methods can be effectively integrated, and whether a public health approach can bring about positive changes in urban and transport planning.

Traffic-Related Air Pollution and Childhood Asthma: Recent Advances and Remaining Gaps in the Exposure Assessment Methods

Background: Current levels of traffic-related air pollution (TRAP) are associated with the development of childhood asthma, although some inconsistencies and heterogeneity remain. An important part of the uncertainty in studies of TRAP-associated asthma originates from uncertainties in the TRAP exposure assessment and assignment methods. In this work, we aim to systematically review the exposure assessment methods used in the epidemiology of TRAP and childhood asthma, highlight recent advances, remaining research gaps and make suggestions for further research. Methods: We systematically reviewed epidemiological studies published up until 8 September 2016 and available in Embase, Ovid MEDLINE (R), and “Transport database”. We included studies which examined the association between children’s exposure to TRAP metrics and their risk of “asthma” incidence or lifetime prevalence, from birth to the age of 18 years old. Results: We found 42 studies which examined the associations between TRAP and subsequent childhood asthma incidence or lifetime prevalence, published since 1999. Land-use regression modelling was the most commonly used method and nitrogen dioxide (NO2) was the most commonly used pollutant in the exposure assessments. Most studies estimated TRAP exposure at the residential address and only a few considered the participants’ mobility. TRAP exposure was mostly assessed at the birth year and only a few studies considered different and/or multiple exposure time windows. We recommend that further work is needed including e.g., the use of new exposure metrics such as the composition of particulate matter, oxidative potential and ultra-fine particles, improved modelling e.g., by combining different exposure assessment models, including mobility of the participants, and systematically investigating different exposure time windows. Conclusions: Although our previous meta-analysis found statistically significant associations for various TRAP exposures and subsequent childhood asthma, further refinement of the exposure assessment may improve the risk estimates, and shed light on critical exposure time windows, putative agents, underlying mechanisms and drivers of heterogeneity.

Full-chain health impact assessment of traffic-related air pollution and childhood asthma

BACKGROUND Asthma is the most common chronic disease in children. Traffic-related air pollution (TRAP) may be an important exposure contributing to its development. In the UK, Bradford is a deprived city suffering from childhood asthma rates higher than national and regional averages and TRAP is of particular concern to the local communities. AIMS We estimated the burden of childhood asthma attributable to air pollution and specifically TRAP in Bradford. Air pollution exposures were estimated using a newly developed full-chain exposure assessment model and an existing land-use regression model (LUR). METHODS We estimated childhood population exposure to NOx and, by conversion, NO2 at the smallest census area level using a newly developed full-chain model knitting together distinct traffic (SATURN), vehicle emission (COPERT) and atmospheric dispersion (ADMS-Urban) models. We compared these estimates with measurements and estimates from ESCAPEs LUR model. Using the UK incidence rate for childhood asthma, meta-analytical exposure-response functions, and estimates from the two exposure models, we estimated annual number of asthma cases attributable to NO2 and NOx in Bradford, and annual number of asthma cases specifically attributable to traffic. RESULTS The annual average census tract levels of NO2 and NOx estimated using the full-chain model were 15.41 and 25.68 μg/m3, respectively. On average, 2.75 μg/m3 NO2 and 4.59 μg/m3 NOx were specifically contributed by traffic, without minor roads and cold starts. The annual average census tract levels of NO2 and NOx estimated using the LUR model were 21.93 and 35.60 μg/m3, respectively. The results indicated that up to 687 (or 38% of all) annual childhood asthma cases in Bradford may be attributable to air pollution. Up to 109 cases (6%) and 219 cases (12%) may be specifically attributable to TRAP, with and without minor roads and cold starts, respectively. CONCLUSIONS This is the first study undertaking full-chain health impact assessment of TRAP and childhood asthma in a disadvantaged population with public concern about TRAP. It further adds to scarce literature exploring the impact of different exposure assessments. In conservative estimates, air pollution and TRAP are estimated to cause a large, but largely preventable, childhood asthma burden. Future progress with childhood asthma requires a move beyond the prevalent disease control-based approach toward asthma prevention.

The Impact of Different Validation Datasets on Air Quality Modeling Performance

Many studies rely on air pollution modeling such as land use regression (LUR) or atmospheric dispersion (AD) modeling in epidemiological and health impact assessments. Generally, these models are only validated using one validation dataset and their estimates at select receptor points are generalized to larger areas. The primary objective of this paper was to explore the effect of different validation datasets on the validation of air quality models. The secondary objective was to explore the effect of the model estimates’ spatial resolution on the models’ validity at different locations. Annual NOx and NO2 were generated using a LUR and an AD model. These estimates were validated against four measurement datasets, once when estimates were made at the exact locations of the validation points and once when estimates were made at the centroid of the 100m×100m grid in which the validation point fell. The validation results varied substantially based on the model and validation dataset used. The LUR models’ R2 ranged between 21% and 58%, based on the validation dataset. The AD models’ R2 ranged between 13% and 56% based on the validation dataset and the use of constant or varying background NOx. The validation results based on model estimates at the exact validation site locations were much better than those based on a 100m×100m grid. This paper demonstrated the value of validating modeled air quality against various datasets and suggested that the spatial resolution of the models’ estimates has a significant influence on the validity at the application point.

Urban and Transport Planning, Environment and Health

The world is currently witnessing its largest urban growth in human history. Over 50% of people worldwide live in cities and this figure is estimated to increase to up to 70% over the next 20 years. Cities have long been known to be society’s predominant engine of innovation and wealth creation, but they are also a main source of pollution, crime and disease. Well-designed and efficient urban and transport systems are essential for cities and their citizens to thrive. Yet, the reality is that current urban and transport development have been less than optimal, creating and exacerbating human exposures to motor vehicle crashes, air pollution, noise, heat islands, lack of green space and sedentary behaviour, to name a few. These trends are associated with a large global burden of disease that has the potential to cripple even the best health care systems. This chapter provides an introduction to the many environmental and health issues that cities face as a result of urban and transport planning and policies. Some examples assessing the health impacts of urban and transport policies are overviewed. Different paradigms for cities and different city initiatives are overviewed. Finally, an introduction to the following chapters is provided.

The Role of Health Impact Assessment for Shaping Policies and Making Cities Healthier

Health Impact Assessment (HIA) is an important tools to integrate evidence in the decision-making process, and introduce health in all policies. In urban and transport planning, HIAs have been used generally to assess qualitatively urban interventions rather than offering more useful/powerful estimations to stakeholders through quantitative approaches. HIAs could answer various pressing questions such as: what are the best and most feasible urban and transport planning policy measures to improve public health in cities? Also the process on how to get there is often as important as the actual output of the HIA, as the process may provide answers to important questions as to how different disciplines/sectors can effectively work together and develop a common language, how to best incorporate citizen and stakeholder, how different modelling and measurement methods can be effectively integrated, and whether a public health approach could make changes in urban and transport planning.

Implementing Car-Free Cities: Rationale, Requirements, Barriers and Facilitators

Cities across the world are beginning to shift away from private cars and towards more sustainable, healthy, just and inclusive mobilities. Hamburg, Oslo and Madrid have recently announced their plans to become (partly) car free. Despite the accepted importance of moving towards such transport systems, many cities struggle with the transition towards becoming car free. We describe the rationale, prerequisites, barriers, facilitators and strategies for car free cities. We describe 9 prerequisites to facilitate the transition towards becoming car free. Compact cities may be easier to refit to car free cities than sprawled cities. The main challenges will be how to change existing infrastructure that was mainly designed for cars to infrastructure for active and public transport, and how to change people’s perceptions, attitudes and behaviors. Retail interest and the car industry may be some of the biggest barriers. More research on cities in the vanguard of becoming car free is needed to urge this transition. Some cities have initiated strategies to create car free spaces. There is a need for creating good and feasible strategies and scenarios, and research evidence which can facilitate the move towards healthier cities.

Socioeconomic inequalities in urban and transport planning related exposures and mortality: A health impact assessment study for Bradford, UK

BACKGROUND Cities have unique geographic, environmental and sociocultural characteristics that influence the health status of their citizens. Identification and modification of these characteristics may help to promote healthier cities. OBJECTIVE We estimated premature mortality impacts of breaching international exposure guidelines for physical activity (PA), air pollution, noise and access to green space for Bradford (UK) adult residents (n = 393,091). METHODS We applied the Urban and TranspOrt Planning Health Impact Assessment (UTOPHIA) methodology and estimated mortality, life expectancy (LE) and economic impacts of non-compliance with recommended exposure levels. We also investigated the distribution of the mortality burden among the population, focusing on socioeconomic position (SEP) as defined by deprivation status and ethnicity. RESULTS We estimated that annually almost 10% of premature mortality (i.e. 375 deaths, 95% CI: 276-474) in Bradford is attributable to non-compliance with recommended exposure levels. Non-compliance was also estimated to result in over 300 days of LE lost (95% CI: 238-432), which translated in economic losses of over £50,000 per person (95% CI: 38,518-69,991). 90% of the premature mortality impact resulted from insufficient PA performance. Air and noise pollution and the lack of green space had smaller impacts (i.e. 48 deaths). Residents of lower SEP neighborhoods had the highest risks for adverse exposure and premature death. A larger number of deaths (i.e. 253 and 145, respectively) could be prevented by reducing air and noise pollution levels well below the guidelines. DISCUSSION Current urban and transport planning related exposures result in a considerable health burden that is unequally distributed among the Bradford population. Improvements in urban and transport planning practices including the reduction of motor traffic and the promotion of active transport together with greening of the district, particularly in areas of lower SEP, are promising strategies to increase PA performance and reduce harmful environmental exposures.