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.

And it doesn’t take an advanced degree to know that mercury is an especially bad actor—a toxin particularly hazardous to pregnant women, to the neurological development of their fetuses and to young children—causing impairments that can last a lifetime.

None of this is really news. What may be news is that the Environmental Protection Agency (EPA) has proposed a change to its Mercury and Air Toxics Standards (MATS) in the form of a new formula for calculating the human health benefits of reducing some of the most hazardous air pollutants from power plants: chemicals that in even relatively small quantities are potent carcinogens, mutagens, teratogens and neurotoxins. Congress specifically recognized these hazards when it enacted Section 112 of the Clean Air Act.

In a somewhat wonky sleight of hand and one that does not bode well for future clean air protections, the agency has proposed a revision to its own finding on MATS. Incredibly, the agency now asserts that it is no longer “appropriate and necessary” to regulate mercury and hazardous air pollution emitted from power plants under the Clean Air Act. In the U.S., power plants are the largest source of mercury, chromium, arsenic, nickel, selenium and the acid gases hydrogen fluoride, hydrogen cyanide and hydrogen chloride. These are highly hazardous pollutants that cause serious harm to humans, wildlife and the environment. And the human health damage is borne disproportionately by people of color and the poor.

In 2012, the EPA estimated that its MATS rule would prevent 11,000 premature deaths and over 100,000 asthma and heart attacks each year, as a result of the co-benefits of the reduction in particulate matter pollution that occurs when plants reduce their mercury emissions. The agency estimated the health benefits of reductions in all air pollutants associated with MATS would range from $37 billion to $90 billion, with compliance costs to industry estimated at $7.4 billion to $9.6 billion annually.

But the EPA has now decided that the health benefits of controlling MATS emissions are only $4 million to $6 million max, if you don’t (and the agency opines that you shouldn’t) count the benefits of controlling the related emissions. This despite the fact that scientists have concluded that the EPA’s 2011 regulatory impact assessment greatly underestimated the monetized benefits of reducing mercury emissions from power plants. Also notable is the fact that most coal plants have already come into compliance with MATS by installing the necessary pollution control technology.

In suggesting that it is no longer “appropriate and necessary” to regulate mercury and air toxics from power plants, EPA Administrator Andrew Wheeler is basically saying that the health benefits are too paltry to justify the costs.

As public health professionals, we strenuously disagree. We suspect that most members of the public will, too.

So, what to do? The EPA proposal is open for public comment through April 17, 2019. It is critical that scientists, health professionals, economists, community advocates, public interest organizations and concerned members of the public express their strong opposition to this drastic narrowing in how the agency evaluates the costs and benefits of critical public health protections.

The American Public Health Association has joined professional medical societies and public health groups in taking legal action to protect limits on MATS pollution and has filed an amicus brief in a related court case. The Union of Concerned Scientists has produced a public comment guide to support and encourage submission of detailed and specific comments during this open comment period. Both organizations will be submitting comments as well.

Make no mistake. Though the current proposal focuses specifically on MATS, it directly challenges the very foundation of clean air regulations. That’s why we and our organizations are speaking out—for the health of our families and our communities today and into the future. Our individual and collective voices matter. We urge you to join us.