If the clean air benefits of COVID-19 lockdowns in New York City could persist for five years after the pandemic, thousands of children and adults would be spared from illness and premature death.
The research, conducted by experts at the Columbia University Mailman School of Public Health, also estimates that the economic benefits of this hypothetical clean air scenario would total tens of billions of dollars.
“New York City (NYC) experienced a sharp decline in air pollution during the COVID-19 shutdown period – albeit at high social and economic costs,” wrote the study authors.
“It provided a unique opportunity to simulate a scenario in which the city-wide air quality improvement during the shutdown were sustained over the five-year period, 2021 through 2025, allowing us to estimate the potential public health benefits to children and adults and their associated economic benefits.”
The goal of the clean air scenario is to inform new policies that can improve air quality – particularly regulations that will reduce harmful emissions from fossil fuel combustion.
During the New York City spring shutdown, the air quality was dramatically improved as a result of an estimated 60-percent decline in automobile traffic combined with declines in air traffic, construction, restaurant operations, and electricity generation.
“We estimated a city-wide 23% improvement in PM2.5 levels during the COVID-19 shutdown months compared to the average level for those months in 2015–2018 (the business as usual period),” explained the researchers.
“Based on the data for 2020, we extrapolated the ambient levels of PM2.5 for the following five-year period. The estimated cumulative benefits for 2021–2025 included thousands of avoided cases of illness and death, with associated economic benefits from $31.8 billion to $77 billion.”
“This ‘natural experiment,’ tragic though the cause, has provided a hypothetical clean air scenario that can be considered aspirational – one that could be achieved through transportation, climate, and environmental policies that support robust economic recovery with similarly reduced emissions.”
The experts used BenMAP, a publicly available computer tool supported by the EPA, to estimate the number of avoided air pollution-related illnesses and deaths.
“The analysis considered outcomes in children that have not generally been accounted for in clean air benefits assessments, including preterm birth, term low birthweight, infant mortality, child asthma incidence, child asthma hospital admissions and emergency department visits, autism spectrum disorder, as well as adult mortality,” wrote the researchers.
Study first author Dr. Frederica Perera is the director of translational research at the Columbia Center for Children’s Environmental Health and a professor of Environmental Health sciences at Columbia Mailman School.
“Air quality improvements from the shutdown happened as the result of a tragic situation,” said Dr. Perera. “However, our hypothetical clean air scenario could be achieved through air pollution and climate mitigation policies, including those that support low carbon modes of transportation and reduce emissions in other sectors.”
The study is published in the journal Environmental Research.