CHICAGO, June 19 (Xinhua) -- U.S. researchers recently linked more than 600,000 cars billed as having "clean diesel technology" sold in the United States between 2008 and 2015 to lower birth weights in approximately 38,600 children.
The additional pollution from the exhaust of these cars was also associated with an increase in acute asthma in infants and children, according to a study.
The researchers at Northwestern University (NU) and the Federal Reserve Bank of Chicago in the study tracked car registrations around the United States to pinpoint where the cheating diesel cars were sold, linking that data to detailed information on pregnancies and births in those counties. They also collected data from the U.S. Environmental Protection Agency (EPA) monitoring stations and satellites to measure air pollution.
The researchers found that each additional cheating diesel car per 1,000 cars in a county led to a 2-percent increase in fine particulate matter, a pollutant known to impair population health; and a nearly 2-percent increase in the rate of low birth weight.
The researchers also calculated an 8-percent increase in asthma emergency department visits among young children in a subsample of five states: Arizona, Florida, Kentucky, New Jersey and Rhode Island.
Children across the socioeconomic spectrum were affected, but the effects were particularly pronounced for children born to white, non-Hispanic mothers with a college degree.
"Our study provides evidence that car pollution affects everyone, not just people living right next to major highways," said co-author Diane Alexander, an economist with the Chicago Federal Reserve. "And for policymakers, we highlight the importance of not only appropriate regulation, but also enforcement."
In the next step, the researchers plan to follow up with studies of outcomes for older children, adults and the elderly that will cover education outcomes, death and disease rates, and labor productivity, among others.
In September 2015, the EPA charged the Volkswagen Group with violating the Clean Air Act, launching what came to be known as "Dieselgate." The EPA revealed that so-called "clean diesel cars" were cheating on emissions tests by using illegal software, known as "defeat devices," to meet U.S. air quality regulations.
Outside of testing labs, the cars were emitting dangerously high levels of nitrogen oxide (NOX) via their exhausts. As shown in previous research, one "cheating diesel" car in real-world driving conditions could emit as much NOX as 150 gasoline-powered cars.
The study, titled "The impact of car pollution on infant and child health: Evidence from emissions cheating," has been published in the university's Institute for Policy Research Working Paper Series.