CDC questioned EPA rule declining to impose tougher soot regulations

The Centers for Disease Control and Prevention (CDC) warned that the Environmental Protection Agency’s (EPA) rationale for freezing air quality regulations was “not scientifically defensible” before the agency finalized the rule earlier this month.

The EPA opted to keep Obama-era standards on particulate matter, or soot, in a move critics argued failed to take into account a growing body of evidence showing even low levels of air pollution can be harmful to human health.

An interagency review of the EPA rule released late Friday shows that the CDC shared those concerns, saying the agency “has not provided sufficient justification” for failing to sufficiently weigh epidemiological studies showing the harm from air pollution at levels lower than the current standards.

“The CDC comments expose EPA’s strategy of downplaying and ignoring these studies of harmful health impacts from air pollution,” said Amit Narang, a regulatory policy advocate at the left-leaning advocacy group Public Citizen.

“One of the primary arguments that EPA has been making in not strengthening air pollution standards is studies that show a strong connection between air pollution and health impacts show those at higher concentrations and can’t be extrapolated to claim those harmful health impacts also occur at lower concentration.,” Narang added.

But the CDC pushed back, arguing that the EPA erred in not relying on research positing that even low levels of particulate matter can be damaging.

“Results from these studies can, and should, be used to directly inform the health effects of pollutant exposures and are invaluable for proper interpretation of epidemiologic findings. As written, the rationale is not scientifically defensible and is inconsistent with established practice within the EPA and other scientific agencies and organizations,” the CDC wrote in its comments. 

There isn’t as large a body of lab studies on how low levels of particulate matter pollution impact health, said Gretchen Goldman, a research director for the Union of Concerned Scientists, in part because such studies would require “a long time and a lot of rats.”

But newer epidemiological research has found health impacts for humans for levels of air pollution below the current Obama-era standards, including premature death.

“This is super embarrassing for EPA that they are getting schooled about epidemiology and EPA process by CDC,” Goldman said, calling it a “bread and butter” issue for the EPA.

Environmental groups had hoped the EPA would adopt more stringent air quality standards during its once-every-five-year review.

The EPA said it decision to keep the current standards came after reviewing the scientific information from its Clean Air Scientific Advisory Committee (CASAC).

“The decision to retain existing Obama-Biden Administration standards came after careful review and consideration of the most recent available scientific evidence and technical information, consultation with the agency’s independent scientific advisors, and consideration of more than 60,000 public comments on the proposal,” EPA spokesman James Hewitt told The Hill by email.

CASAC’s recommendations have faced heavy scrutiny, however, after all its original members were replaced during the Trump administration.