https://blogs.scientificamerican.com/observations/yes-epa-regulating-mercury-pollution-is-appropriate-and-necessary/

It doesn’t take a health care professional, public health expert or environmental scientist to understand the value of clean air and the need for regulatory safeguards that protect our families and communities from toxic air pollution. While killer smog may seem like an historical artifact, air pollution exacts a significant toll globally and on our own nation’s health and economy.

The scientific evidence and health data are clear; exposure to toxic and hazardous air pollutants can result in premature death and cause a host of cancers, lung and heart diseases, adverse reproductive outcomes, birth defects, and neurological and cognitive impairments that can have lifetime impacts. In addition to pain, suffering and disability, these health impacts have significant economic, social and emotional costs for patients, their families and their caregivers—from doctors’ appointments, emergency department visits, and medications, to lost workdays, missed school days, and restrictions in daily living.