University of Houston study shows electric vehicles can have a positive impact on air quality and public health in some cities, but not all

What do Houston, Los Angeles, New York and Chicago have in common? Dense population, high traffic volume, and air quality that does not meet ozone standards set by the U.S. Environmental Protection Agency. These circumstances made each city a prime candidate for a University of Houston study assessing the impact of vehicle electrification on air quality and public health.

Titled “Air quality and health co-benefits of vehicle electrification and emissions controls in the most populous urban centers in the United States: insights from New York, Los Angeles, Chicago and Houston” , the study examined changes in air pollution, particularly PM2.5. and ozone levels in these major American cities under different electrification scenarios. The work was published in the journal Science of the Total Environment.

The study found that by switching to electric vehicles, Houston could avoid 157 premature deaths each month, while New York and Chicago could see even greater benefits, avoiding 796 and 328 premature deaths per month, respectively. In Los Angeles, a scenario calling for a 29% share of electric vehicles for light vehicles could save 104 lives each month, but full electrification could increase mortality in Los Angeles due to higher levels of PM2.5 and ozone.

“Our results indicate that vehicle electrification generally helps reduce greenhouse gas emissions, improve air quality and reduce the mortality rate associated with exposure to toxic air pollutants,” said the paper’s first author, Ali Mousavinezhad, a Ph.D. from the Department of Earth and Atmospheric Sciences in the UH College of Natural Sciences and Mathematics this year.

“However, due to the complex atmospheric chemistry and unique meteorological and geographic conditions of Los Angeles, complete electrification could lead to increased secondary aerosol concentrations, which could have adverse effects on human health and the economy by increasing mortality rates,” he added. “This highlights the need for region-specific environmental regulations. »

Under the full electrification scenario, also known as FullE, levels of PM2.5 – tiny particles that can damage our lungs – fell to as low as 2.29 μg/m³ in many regions. Surprisingly, parts of East Los Angeles saw PM2.5 levels increase as high as 0.67 μg/m³. This was due to an increase in secondary organic aerosols, driven by changes in the dynamics of nitrogen oxides and volatile organic compounds, as well as a peak in hydroxyl radical concentrations.

The unique climate and geography of Los Angeles and its surrounding areas, including a mountain range to the east, can trap air pollutants in downwind areas. This can lead to higher concentrations of pollution.

The study also found significant reductions in nitrogen oxides and 8-hour maximum daily average ozone levels in the FullE scenario, with drops to 14.00-32.34 parts per billion and 2.58- 9.58 ppb, respectively. However, some areas experienced an increase in MDA8 ozone, highlighting the complexity of air quality management.

Economically, the FullE scenario promises significant health-related savings, ranging from $51 million to $249 million per day for New York, Chicago, and Houston. Conversely, Los Angeles could suffer economic losses of up to $18 million per day.

“The four largest U.S. cities have distinct anthropogenic sources of air pollutants and greenhouse gases,” said Yunsoo Choi, corresponding author and professor of atmospheric chemistry, AI deep learning, climate modeling. air quality and satellite remote sensing. “Each city requires unique regulations or strategies, including different EV adoption scenarios, to effectively reduce concentrations of these pollutants and greenhouse gases. »

The overall impact on air quality is a more complex undertaking than many realize. Estimating future scenarios related to electric vehicles and changes in other sources – such as industry, residential areas, biogenic emissions, ocean emissions and others – contribute to this complexity.

However, Choi and Ali see many opportunities in the current drive to electrify the transportation sector.

“In the future, we expect an increase in the number of electric vehicles on the roads, which will help reduce emissions of air pollutants and greenhouse gases from vehicle exhausts. By considering the expected percentage of electric vehicles in the future, we can estimate the impact of these changes on concentrations of air pollutants and greenhouse gases, which ultimately affect human health,” Choi said.

This study shows that there is no universal solution. Effective and nuanced air quality management is essential to a cleaner, healthier world. “The results of this study will help policymakers adapt their regulations to the specific characteristics of different regions in order to improve the quality of life,” Ali said.

As America and the world move toward a greener future with electric vehicles, these findings highlight the need for a balanced and thoughtful approach to ensure that both the environmental and public health benefits are fully realized. carried out.