Little Green Molecules

Chemists have invented a new class of catalysts that can destroy some of the worst pollutants before they get into the environment

By Terrence J. Collins and Chip Walter

Join Our Community of Science Lovers!

On supporting science journalism

If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.

The fish that live in the Anacostia River, which flows through the heart of Washington, D.C., are not enjoying its waters very much. The Anacostia is contaminated with the molecular remnants of dyes, plastics, asphalt and pesticides. Recent tests have shown that up to 68 percent of the river's brown bullhead catfish suffer from liver cancer. Wildlife officials recommend that anyone who catches the river's fish toss them back uneaten, and swimming has been banned.

The Anacostia is just one of dozens of severely polluted rivers in the U.S. The textile industry alone discharges 53 billion gallons of wastewater--loaded with reactive dyes and other hazardous chemicals--into America's rivers and streams every year. New classes of pollutants are turning up in the nation's drinking water: traces of drugs, pesticides, cosmetics and even birth-control hormones. The amounts are often infinitesimal, measured in parts per billion or trillion (a part per billion is roughly equivalent to one grain of salt dissolved in a swimming pool), but scientists suspect that even tiny quantities of some pollutants can disrupt the developmental biochemistry that determines human behavior, intelligence, immunity and reproduction.

Subscribe to Support Independent Journalism

Great science journalism requires human expertise, time, effort and creativity. And it costs money. That’s why I and the journalists here at Scientific American hope you’ll join our community.

When you subscribe, you are supporting staff and freelance journalists who are passionate about telling science stories that are true, important and compelling. Our editors and reporters are often experts in their fields, which means they understand the nuances of big discoveries and can untangle the breakthroughs from the hype. With a subscription, you are also supporting rigorous fact-checking to ensure the words we publish are precise and accurate. And you’re supporting original illustrations, graphics and photos that bring you closer to an advanced laboratory, an ice sheet in Antarctica or a space mission in orbit. You’re helping us craft other types of high-quality journalism as well: Our newsletters are carefully written, edited and curated by staffers you have or will come to know and love. Our Science Quickly podcast is based on original reporting, collaboration with editors and scientists and exacting production.

Subscriptions keep this engine running so we can continue to deliver thoughtful, rigorous and independent science journalism to you. In an era of viral misinformation, this work is crucial. If you value what we do, I hope you’ll consider joining us as a subscriber

Thank you,

Jeanna Bryner, Editor in Chief, Scientific American