03/25/2015 12:20 pm ET Updated May 25, 2015

Polluters Again Challenge Common-Sense Public-Health Protections at the Supreme Court

Today the Supreme Court will hear polluter arguments against the Environmental Protection Agency's (EPA) vital Mercury and Air Toxics Standards (MATS), a long-overdue protection finalized in 2012 that will help guard our families, air, water, and wildlife from dangerous toxic pollution that comes from coal plants. These vital protections are critically important to public health, and the polluters challenging them are putting lives at risk.

The mercury, arsenic, and other poisonous metal and acid gas pollution that these protections are meant to control pose serious dangers to pregnant women and young children. EPA scientists have estimated that as many as one in 10 women has mercury levels in her blood high enough to cause damage to a developing baby. I know I worried about this when I was pregnant with my daughter five years ago, and I still worry about it now as she grows up.

That's why thousands of Sierra Club supporters worked with our partner organizations for years to push for these standards. I'll never forget appearing on Good Morning America in 2010, when I was a sleep-deprived new mom, to reveal the results of a mercury hair test taken by their weatherman, Sam Champion. It turned out that his mercury levels were two times higher than what the EPA recommends as safe -- much to his shock and surprise. How did his mercury levels get so high?

As the nation's largest source of mercury emissions, coal plants are responsible for 48 tons of this toxin being released every year. It falls from the smokestacks into our rivers, lakes, and oceans, making its way into the aquatic food chain, and perhaps to the seafood counter at your local grocery store. While eating seafood is part of a healthy diet, a few species of fish are known to be high in mercury -- which is why pregnant women are warned to avoid eating them by their doctors.

In fact, all 50 states currently issue mercury advisories warning anglers to limit or avoid eating the fish they catch, due to high mercury levels in some fish. As of 2010, almost 18 million lake acres and approximately 1.4 million river miles were covered by some type of fish consumption advisory.

That is why the EPA's mercury protections are so critically important. Designed to be enacted over time, these safeguards will prevent up to 11,000 premature deaths, more than 100,000 asthma and heart attacks, and more than 5,000 emergency room and hospital visits each year once fully implemented. The EPA estimates that these life-saving protections will also save taxpayers up to $90 billion in healthcare costs annually -- a savings of as much as $9 for every dollar invested in cleaning up dirty coal plant pollution.

So who in their right mind would attack these mercury protections? No surprise, but once again it's several polluting industries and their political allies who put profits before people and public health. For more on the legal arguments before the Supreme Court today, Sierra Club managing attorney and MATS expert Sanjay Narayan has written a column that I highly recommend.

In this latest legal challenge, polluters asked the Supreme Court to ignore the public health benefits these new protections will bring and focus only on the companies' balance sheets. This in spite of the fact that the vast majority of coal plants across the country have already installed or are planning to install the needed equipment to comply with the mercury protections. These plants that have already cleaned up have shown that protecting our communities from this pollution isn't just possible but is already happening and is the right thing to do.

The most stubborn polluters, however, are still challenging the EPA on whether the agency adequately considered their costs before finalizing the mercury protections. It doesn't take a rocket scientists to see that this is in part a delaying tactic, since the protections will be mostly implemented by the time the Supreme Court even reaches a decision.

Additionally, it's clear that the EPA's analysis fully met the requirements of the law. The agency carefully studied the public health harms caused by power plants and determined that those harms were indeed enormously grave. It then set common-sense standards, based on the pollution reductions achieved by already operating plants, which is exactly what Congress told the EPA to do. The agency's assessment of the protections are also a real bargain for the American public, with benefits outweighing costs by as much as 9 to 1.

It's important to remember that in the 40 years since Americans demanded the creation of the EPA, the agency has saved millions of lives by developing and enforcing clean air and water standards. More than 1.7 million asthma attacks and $110 billion in health costs were avoided in 2010 alone thanks to the agency's efforts to clean up air and water pollution. These mercury protections, which were finalized by the EPA and upheld by the D.C. Circuit, are an essential next step in fulfilling the agency's mandate of safeguarding the health and safety of the American people.

The Sierra Club and many other environmental and public health organizations agree: Turning back the clock on that progress makes no sense and would deal a huge blow to our most vulnerable neighbors and family members. Even The New York Times' editorial board blasted the legal attacks in a scathing piece this week.

The Supreme Court must stand up for public health. But no matter the outcome of this Supreme Court decision, we will continue fighting to clean up this dangerous pollution once and for all.