"EPA issued a new draft report acknowledging evidence that its current standards for airborne fine particulates are not tight enough to adequately protect public health.
A "causal relationship" exists between short-term exposure to fine particulates and the risk of premature death, according to the draft report, formally known as an integrated science assessment.
EPA's current annual standard, set in 2012, is 12 micrograms per cubic meter of air. But the report notes that U.S. studies "indicate a linear relationship at levels as low as" 5 micrograms per cubic meter. Particularly vulnerable are children, based on "strong evidence of impaired lung function growth," and minorities, the draft adds."