Why EVs must replace—not supplement—existing gas-powered vehicles for meaningful public health benefits.
Highlights
- About one-third (18%–42%) of childhood asthma cases are due to traffic-related air pollution.
- Our research reveals there are already measurable public health benefits in US States that have seen growth in EV share.
- Replacing ~21% of gas-powered new car sales with EVs halts rising asthma rates caused by new sales.
- We recommend developing targeted programs to replace older fossil-fuel-based vehicles and subsidies to encourage lower-income households to switch from older, fossil-fuel-based vehicles to EVs.
Background
Do you know a big chunk of new asthma cases come from gas-powered automobiles? When gas-powered automobiles burn fossil fuels, they release harmful air pollutants like nitrogen oxides and particulate matter that are directly linked to adverse health outcomes. Given this, how can we prevent additional asthma cases from arising? One way would be to limit the exhaust from automobiles, which can be achieved by transitioning to cleaner electric vehicles (EVs).Significance
Public health unites us in ways few other fields can. Our research examines sustainable transportation policies in the US from a public health perspective. We show the rise in adoption of electric vehicles (EVs) from 2013 to 2019 produced a measurable decrease in the incidence of childhood asthma. Historically, one new case of childhood asthma arises for every thousand new gas-powered vehicles (non-EVs) sold. Replacing approximately 21% (7-42%) of these new car sales with EVs is sufficient to halt the trend of growing asthma rates due to new sales. We project that once EVs reach about half of all vehicles on the road, childhood asthma from tailpipe emissions virtually disappears. This market share can range from 36% to 77% based on population density, size of existing fossil-fuel-based fleet, and geography of the neighborhood. These findings underscore the urgent need for policies to accelerate the replacement of older fossil-fuel-based vehicles with EVs and the adoption of EVs by lower-income households that are disproportionately affected by traffic-related air pollution.
As the authors of this paper, we do not want readers to assume that more EVs are the only solution to improved public health. We have to be cautious about two things: (1) reduction in childhood asthma only manifests when EVs are sold as replacements for new non-EVs (e.g., when people buy EVs as a second vehicle, we don’t see the same health benefits; the biggest benefit is when people replace older fossil-fuel-based vehicles with EVs) and (2) EVs—as any other vehicle—contribute to non-tailpipe emissions in the form brake wear, tire wear, and road dust, which are also linked with adverse health impacts, so alternative forms of transport are still important to keep the total number of cars down to mitigate these impacts. Other critical limitations of the EV technology that need to be addressed before broader adoption involve concerns about the production and recycling of batteries, social injustices in acquiring raw materials, and restrictions on the right to repair. EVs are not the silver bullet, yet we need them to move away from fossil fuel-based vehicles. Bikes and public transport remain important.
Four considerations to ensure EVs have positive health impacts
- Replacing Old Cars with EVs: We need to make sure that EVs are used to replace old fossil-fuel-based cars. This way, we're actually reducing pollution instead of just adding more cars to the roads.
- Broader Adoption of EV-Friendly Policies: States and provinces should adopt EV-friendly policies to replace old vehicles and provide subsidies to lower-income communities. These policies can help get rid of older, polluting cars and spread the health benefits more widely. We also recommend developing targeted programs that include subsidies to encourage lower-income households to switch from older, fossil-fuel-based vehicles to EVs so that the benefits of green technology can be equitably distributed.
- Clean Up the Power Grid: For EVs to be truly beneficial, the electricity they use needs to come from clean sources. If the electricity comes from coal or other fossil-fuel-based sources, then we’re just moving the pollution from the roads to somewhere else, which might still harm people’s health.
- Invest in Public Transport and Biking Infrastructure: Our findings doesn’t point towards a 1:1 replacement of gas-powered automobiles with EVs to maximize public health benefits. Some air pollutants like nitrogen dioxide are highly reactive and have a relatively shorter lifespan, so reducing even a few sources can have a considerable health impact. Part of these health benefits comes from the ability of nitrogen dioxide to quickly dissipate in the atmosphere. While a 36-77 per cent fleet share of electric vehicles should minimize the asthma burden due to reducing the amount of nitrogen dioxide emitted from gas-powered automobiles, this doesn't remove all the pollutants. EVs do not emit exhaust fumes, but, like any other vehicle, they produce pollution from tire and brake wear, known as non-tailpipe emissions. Until, we find the ways to reduce these pollutants, we need to limit the number of vehicles on the road. We need to invest in public transport and biking infrastructure.