WASHINGTON – While the Trump administration has made deregulation a priority, some of the anticipated public health consequences are stunning – and unpopular among many local politicians.

Hundreds of mayors united this week, signing a letter opposing President Donald Trump’s decision to roll back the Clean Power Plan – former President Barack Obama’s signature policy for reducing emissions from coal-fired power plants — and replace it with a more limited version.

Representing 47 states and territories, 236 U.S. mayors wrote in a letter addressed to Environmental Protection Agency administrator Scott Pruitt that the Trump administration’s attempt to roll back the environmental restrictions would have “devastating health and economic impacts on their communities.”

In his first 100 days in office, Trump rolled back 23 environmental rules with the help of Pruitt, the former Oklahoma attorney general who made it his mission to tie up the Clean Power Plan in court, challenging it repeatedly during his tenure. Additionally, Trump eliminated 67 regulations in his first year in office, his administration boasting it “canceled or delayed over 1,500 planned regulatory actions.”

One day after Trump spoke at the Davos world economic forum in late January, where he championed deregulation, Office of Information and Regulatory Affairs administrator Neomi Rao said regulations like the Clean Power Plan no longer “worked for the people.”

The benefits of the environmental regulation were exaggerated and the costs under-reported, she told reporters at an event at the Brookings Institution in Washington. The administration’s focus on deregulation, she said, is good for business.

However, such rampant deregulation will have vital consequences for the communities these laws were supposed to protect.

Environmentalists and scientists say the anticipated loss of the Clean Power Plan is a prime example of the harm deregulation will do. The Trump administration signed an order in October to kill the plan to combat climate change. The Obama policy was essential to keeping the U.S. in compliance with the Paris Agreement, the international global warming agreement, which Trump walked away from before his first six months in office had elapsed.

The Trump administration’s replacement for the Clean Power Plan is likely to be far more limited in scope, experts say, with enormous adverse consequences for public health.

Obama’s Clean Power Plan — which was repealed by the EPA in October — regulated the entire electrical grid, from the source of emissions down to the consumer. It was designed to reduce heat-trapping carbon emissions that contribute to global warming but to also reduce the spread of tiny particles that become deeply embedded in people’s lungs and contribute to asthma and other respiratory ailments.

The Clean Power Plan required states to cut carbon emissions by shifting from coal power to natural gas and renewables over 15 years.

Many expect the EPA to follow a limited approach to the regulation of carbon dioxide emissions, focusing on emissions producers but not other sources of pollution.

The proposed approach would create new pollution hotspots in states including Texas, Illinois, Indiana, Michigan and Ohio, according to scientists at Harvard T.H. Chan School of Public Health and Syracuse University, whose 2015 study looked at the health-related costs of the Clean Power Plan and a limited plan, compared to no regulations put in place at all.

“Replacing the Clean Power Plan with something weaker would have impacts on public health, in short putting more lives in danger,” said Jeremy Richardson, a senior energy analyst at the Union of Concerned Scientists. “Relaxing the rule would allow coal plants to pollute more, increasing not only carbon dioxide emissions but also criteria air pollutants –– and the pollution would be concentrated in places where the oldest and dirtiest plants are.”

Mayors in each of the five states hardest-hit by the repeal signed the letter to Pruitt sharply criticizing the repeal of the plan, not only for the anticipated health effects on their constituents, but also for the refusal to take into account the way pollution travels over state lines.

“The legal authority of cities and other municipalities generally extends only as far as their state governments and federal law allow, and as a result, our local efforts to address climate change are highly sensitive to national policies like the Clean Power Plan, which shape markets, steer state action, and have large direct impacts on nationwide emissions,” they wrote.

Action taken by state government can only go so far without cooperation from the federal government.

“There is a fair amount of air pollution that crosses state boundaries,” said Jonathan Buonocore, research associate at the Harvard T.H. Chan School of Public Health, and one of the authors of the study. “We tend to think of air pollution as coming in hotspots but with these kinds of pollutants, they do have the capacity to be on a regional, continental, or even global scale.”

While some businesses might benefit from having to comply with fewer regulations, cutting environmental regulations comes at a cost to the community.

Although the focus of the Clean Power Plan was to reduce carbon emissions, it would also lower co-pollutants, which are pollutants emitted alongside carbon dioxide. These can come in the form of tiny particles that embed themselves in peoples’ lungs, aggravating heart and lung conditions, or causing asthma.

“There’s no small enough size that doesn’t cause some sort of public health impact,” said Richardson. “When the researchers have looked at it, they find that this stuff really does harm people on some level.

Dave Cortez, an organizer with the Sierra Club in Austin, Texas, who advocates for those in the coal industry and others affected by coal in Texas, has spoken with people already experiencing the negative effects of living alongside coal-fired power plants, such those living near the Martin Lake Power Plant, a Luminant-owned plant east of Dallas.

“We’re seeing people who are having issues with their breathing,” Cortez said. “They’ve lost their sense of taste and they’ve been around these plants for decades.”

Aside from the towns that border coal-fired power plants, Cortez said, no community has been harder hit in Texas than the Dallas-Fort-Worth area. The air, he explained, was particularly toxic to children.

“Keeping the emissions up –– that means more asthma-triggering pollution for children,” he said. Asthma is a terrible problem in Dallas and on high-ozone days, coal plants like Martin Lake contribute significantly to the toxic cocktail that forms ozone, according to Cortez.

Without regulations like the Clean Power Plan to protect them, inhabitants of these hotspots will face further health issues. Nonetheless, the Trump administration is pursuing its deregulatory agenda regardless.

Since taking office, Trump has pledged to return regulations to the level they were in the 1960s. Standing in front of a stack of paper in December 2017, meant to symbolize a wild, unchecked growth of regulations and business-unfriendly laws, Trump told reporters that his administration was “here today for one single reason: to cut the red tape of regulation.”

Trump later boasted during his State of the Union address that his administration has “ended the war” on coal and other fossil fuel production while eliminating more regulations in his first year in office than any other administration in history.