With Thanksgiving quickly approaching—the rare time when the country has a moment to collectively celebrate reflection and gratitude—I’m reminded of the inspiring people we get to work with who are changing the world.

One person who comes to mind is Dr. Mona Hanna-Attisha, a recipient of the 22^nd Heinz Award for Public Policy, whom I had the privilege of meeting in Pittsburgh last month as part of a day-long celebration of the Heinz Awards winners. The Heinz Awards are an annual accolade recognizing remarkable individuals who have made outstanding contributions to improve the lives of others.

Dr. Hanna-Attisha is a pediatrician and public health advocate who stepped forward to expose the lead-tainted water in Flint, Michigan, and ignited a nationwide conversation about lead and drinking water safety.

In a presentation she gave at one of the day’s events, she emphasized that lead poisoning is a silent pediatric epidemic. Exposure to lead does not cause immediate physical symptoms, but creates neurological and other problems in children that can lead to behavioral changes and lifelong health challenges.

“There is no safe level of lead in our drinking water,” Dr. Hanna-Attisha repeated.

[caption id=”attachment_10044” align=”alignnone” width=”1200”] Dr. Mona Hanna-Attisha speaks at the Heinz Awards celebration.[/caption]

In her closing remarks, she told the audience of 100, “As a pediatrician, our children’s future is very much my job. But this needs to be all of our jobs, for our kids in Flint and our kids everywhere. They are counting on us.” It was a moving rallying cry and the culmination of a very sobering speech.

What struck me about Dr. Hanna-Attisha was her demeanor after she spoke. I remember seeing her circled by reporters, audience members, and colleagues. Dr. Hanna-Attisha made a point to stop to talk to everyone—and with a smile. Although she has gained celebrity status, lauded as a national hero by major media outlets, she remains humble and committed to her work.

The struggle for clean water isn’t over in Flint. Residents are still drinking bottled water and are waiting on 20,000 lead pipes to be replaced. And, other cities across the country—including Pittsburgh—have lead in the water supply due to aging infrastructure that is endangering children’s lives.

I’m thankful for courageous, thoughtful leaders and genuinely good people like Dr. Hanna-Attisha, and her fellow Heinz Awards winners, who are relentless in their efforts to tackle big challenges and make our world a better place.

Read more about the 2017 Heinz Awards honorees. And, if you’re interested in learning more about the epidemic of childhood lead exposure, my colleague Kelly Miterko recently wrote an excellent blog post on it.