Today, the Environmental Protection Agency celebrated the 40th anniversary of one of our nation’s most successful and most protective laws, the Clean Air Act.

Commemorating the milestone anniversary with a full day of speakers, keynotes and panel discussions, the agency was joined by a host of industry leaders, business CEOs, clean air advocates and environmental champions to discuss just how far we’ve come in cleaning up our air and protecting people’s lungs and lives from toxic and dangerous air pollution.

For proof on how far we’ve come, here’s some of the pudding:

According to an EPA analysis, the first 20 years of Clean Air Act programs, from 1970 to 1990, prevented:

• 205,000 premature deaths
• 672,000 cases of chronic bronchitis
• 21,000 cases of heart disease
• 843,000 asthma attacks
• 10.4 million lost I.Q. points in children – mostly from reducing lead in gasoline
• 18 million child respiratory illnesses

In 1990, the act was revised with overwhelming bipartisan support in Congress. And from 1990 through 2008, emissions of six common pollutants have been brought down by 41 percent, while gross domestic product has grown 64 percent (For some highlights from 40 years of the Clean Air Act, read here).

But still, each and every victory for clean air in America has been fought tooth and nail by polluter industries. Every step along the way — while lives were being saved and businesses and the economy were growing — polluter industries have tried to stand in the way of this progress, claiming that better and safer pollution controls were going to be the end of business in America.

Of course, as dead-set they were in their claims, they were just as dead-wrong. Today, we heard Administrator Lisa Jackson respond to decades of such bogus claims from polluter industries who have continued to avoid regulation.

“Say what you want about EPA’s business sense, but we certainly know how to get a return on our investment," she said, hoisting the fact that the Clean Air Act returns in environmental and health economic benefits are 40 times what it costs in compliance — in real dollar terms.

But despite these indisputable facts, we continue to hear these same false refrains by big polluters — especially now that the EPA has a mandate to reign in the carbon pollution of the nation’s biggest polluters. One couldn’t possibly be surprised that they object — they have been fighting for free reign to pollute our air and waters relentlessly for four decades.

The bigger surprise should be that there are some members of Congress who want to stand in the way of the EPA and of the Clean Air Act, despite what it has done for our nation.

Sen. Lisa Murkowski (R-AK) led this backwards thinking in June when her legislation to block the EPA from controlling carbon pollution, came to the floor for a vote. The Senate narrowly defeated this terrible measure.

Even though this attempt to overturn progress was defeated, we are still seeing plays in the Senate to stop the EPA and stand in the way of cleaner air in America. Of late, there had been an expectation that some polluter industry allies who sit on a key budgeting committee were going to try to block the EPA by cutting of its funding — and that could have happened as early as this Thursday.

Sen. Murkowski’s spokesperson said that she had been considering blocking the EPA by using her position on this budget committee to offer an amendment that would block its funding. Luckily, those senators won’t get a chance to obstruct progress after all, as the appropriations committee has postponed its markup of the EPA spending bill. To be sure, though, they’ll be looking for their next opportunity.

Sen. Jay Rockefeller (D-WV) is another senator who is trying to stand in the way of progress. He has written legislation which would delay the EPA’s ability to do anything on climate change — and this delay would be horrible for our country. Our economy, our health and our future cannot afford any more delays.

In fact, not only do we absolutely need to stay the course on following the Clean Air Act and allowing the EPA to do its job of protecting the American citizens from harmful and damaging pollutants, but we also need the EPA to do much more to strengthen our air protections.

For too long, big polluters have been given loopholes and exemptions, and old dirty power plants that were supposed to be cleaned up decades ago somehow have avoided that all these years. And many are looking to renovate and expand while still avoiding modern pollution control technologies.

Today, Earthjustice president Trip Van Noppen issued a statement on how far we’ve come under the Clean Air Act, and the unfinished business that still remains on cleaning up these big polluters.  Read Trip’s statement and more about the unfinished business here.

We need the Obama administration, Lisa Jackson and the EPA to do the work that has long been overdue: To clean up the worst actors in our country and finally hold them accountable for their harmful pollution. That pollution is poisoning our air and contiminating our waterways, and it’s time for these industries to finally be held responsible under the Clean Air Act.