One single policy intervention can impact different aspects of society. For instance, realizing decreased automotive mobility may reduce pollution, improve human health, reduce greenhouse gas emissions, increase economic growth, impact physical activity and obesity, mitigate droughts and floods, affect economic inequalities, and increase average workers productivity and intelligence coefficient. However, in addition to mitigation co-benefits, policy interventions to mitigate climate change may also have detrimental impacts on population health and health inequalities. In the ELLIS project, we will therefore adopt a holistic, one health approach for evaluating the effects of the concerned policy interventions.
Less people driving a car is less myocardial infarctions and less sea level rise
How do mobility policies affect air pollution, human health and global warming? Ambient air pollution is causing the largest burden of environmental disease in Belgium with > 10 000 deaths annually estimated to be attributed to ambient air pollution (particulate matter < 2.5 µm including black carbon and ultrafine particles (PM 0.1) plus nitrogen dioxide and ozone). Road traffic is the dominant source of nitrogen dioxide, Black Carbon and Ultrafine Particles and also responsible for a significant fraction of PM 2.5 (that has multiple sources including traffic, residential warming, industry and agriculture) emissions and exposure. Road traffic is in addition responsible for 1/5th of greenhouse gas emissions in Europe. In comparison, cycling and rail transport are respectively responsible for 0.0% and 0.1% of total greenhouse gas emissions in Europe (1,2).
While climate change and air pollution are two distinct phenomena, air pollution (especially NO2, BC, UFP) has a major local component (measures directed to reduce air pollution within Belgium will generate positive health impacts in Belgium), and climate change (greenhouse gases such as CO2) is predominantly global (emissions contribute to global greenhouse gas emissions). Therefore, local traffic measures towards reduced car use on national level, and even at city level, can have considerable benefits for the health outcomes in Belgium by reducing disease, hospitalisations and deaths resulting from air pollution and noise stress. Reduced exposure to the aforementioned pollutants affects amongst others the cardiovascular domain (e.g., by reducing myocardial infarctions), respiratory domain (e.g., by reducing asthma attacks and reducing incidence of paediatric asthma) and neurological domain (e.g. reducing dementia, increasing productivity and increasing mean intelligence coefficient). Additionally, the policy intervention reducing car use also cuts the amount of greenhouse gas emissions and thereby contributes to combating climate change.
How a modal shift away from cars can help mitigate both droughts and floods
How we move can affect how many people’s basements flood during a severe thunderstorm and how frequent and intensive droughts periods are. One of the main reasons that we experience more frequent and more severe periods of drought is the (increasing) concreting of our earth’s surface. Concrete surfaces include built-up areas such as houses, car lanes and car parks. Modal shift policies would allow us to reduce the number of car lanes and car park facilities considerably, thereby also having an opportunity to significantly contribute to improving the imperviousness of the earth’s surface. This would help increase the percolation of surface water into the groundwater table and prevent severe droughts in the future even with a changing climate. Increasing infiltration of water to the groundwater table with 20% is eleven times as effective as reducing groundwater use with 20% (3). Conversely, the number of flooding episodes would be reduced as the concrete surface also prevents the quick uptake of rainwater during heavy rainfall episodes. A reduction in the use of cars and car parks allows more urban green spaces to exist for recreational and other purposes, having an important social impact.
How mobility policies can make you (lose) fat
In a final example, existing scientific research demonstrates that multimodal transport (e.g., a combination of walking and taking a train or cycling and taking a train) is associated with reduced obesity and increased physical activity compared to using car-dominated transport (4,5). Mobility policies can therefore indirectly affect obesity incidence rates and related health complications such as diabetes. The latter disease is not only affected in this way, also air pollution such as particulate matter and nitrogen dioxide can directly affect insulin resistance thereby contributing to the development of type-2 diabetes (6). This again shows the complexity and interconnectivity of those issues.
Policy interventions for health can affect your socio-economic status
Furthermore, the exposure to environmental stress, such as air pollution, can also have important socio-economic aspects, for example, there are socio-economic inequalities in the groups of people exposed to elevated (health-damaging) air pollution concentrations. In some areas, deprived socio-economic groups breathe elevated amounts of vehicle emissions while responsible for a lower share of those emissions compared to the non-deprived population (7). In the latter case, this policy intervention of reducing car-use and car-parkings has the ability to reduce socio-economic inequalities while on the other hand mitigation policies that can worsen socio-economic inequalities also exist, such as road pricing for people living in deprived areas where there is no public transport available.
How policy interventions for climate change can worsen your health
We focused so far mainly on the possibilities of beneficial synergies of single policy interventions on multiple domains. The opposite can also happen, of course. While warming your house with a wood stove replacing oil furnaces partially mitigates greenhouse emissions, it is associated with increased particulate air pollution and consequently negative effects on human health.
How all this is relevant within our ELLIS project
Within the framework of the ELLIS project, we will conduct scientific research on the environmental burden of disease and environmental health inequalities. For this we will, amongst others, look to assess the impact of specified policy interventions on the exposure to environmental stress and consequently the impact on health outcomes and health inequalities. The examples presented here illustrate the complexity of policy interventions. Policy interventions designed for one specific problem might seriously impact other considerable problems, either in a beneficial or detrimental way. It is therefore always important to have a holistic view and never forget to look at the bigger picture. It’s important to consider interactions between the different domains, interactions that are often very relevant for the environment, economy and inequalities, human health and animal health at once. This is also in line with the “ONE HEALTH” philosophy promoted by Sciensano (8).