I have spent 17 years working on toxic pollution. I came to it the way most people in this field do: by accident.

In 2002, after college, I moved to Japan to teach English. I lived in a small fishing town for two years. What stayed with me wasn't any single thing, but a pattern: the rigorous recycling, the efficiency built into nearly every system, the cleanliness of public spaces, and a quiet sense of duty about caring for places and things. The house I lived in had an on-demand water heater, the kind that warms water only when you turn the tap. Small detail, but it captured the larger ethic. That way of thinking shaped me, and eventually led me through a year of travel in low and middle income countries and on to environmental law at Lewis and Clark.

I arrived in New York in 2009, in the teeth of the financial crisis. There were no jobs. I realized I would need to work for free somewhere to prove I could add value, and I didn't want it to be at a law firm. I found a Craigslist ad for an internship at the Blacksmith Institute, the organization that would later become Pure Earth. I'm grateful I didn't have too much pride to take it. Over the next 17 years I held every title prefix the organization uses, from intern to president, and I learned the work from the inside out.

Pure Earth does three things. We assess the prevalence and severity of exposure to pollutants like lead and mercury. We identify the sources, whether contaminated consumer products, food, active industry, or legacy industrial sites. And we fix the problem, through policy, regulation, engineering, or behavioral change. The work is unglamorous and slow, and it has to happen in partnership with governments, because governments are the only entities with the durability and authority to hold the gains.

Lead poisoning harms one billion children, costs the world six trillion dollars a year, and gets less attention than almost any other comparable health crisis. It is the largest preventable environmental health problem on earth. In 2020, I led a strategic shift that defined Pure Earth's next decade. The data, especially the work coming out of IHME and the Lancet Commission, was clear: lead was causing more damage than almost anything else we touched.

Mercury, one of the WHO's 10 chemicals of major public health concern, was less clearly the second-worst, but Pure Earth had two decades of operational experience and a clear path to add value. We narrowed our focus to those two. Saying yes meant saying no to a great deal of legacy work, and that is the hardest choice a nonprofit ever makes. It was the right one. In the years since, l've led Pure Earth's proposals to Bloomberg Philanthropies, Coefficient Giving, and the Audacious Project. Together those commitments have tripled our annual budget and given us the runway to operate at the scale the problem actually demands.

I believe a few things about where this work is going. Our current estimates of lead's global toll are almost certainly too low, and the number will keep rising as the science improves. Governments, not NGOs, will solve this problem. Pure Earth's role is to be the catalyst that makes government action possible. Al and better modeling will reshape the economics of exposure assessment, so that not every country needs a full nationally representative blood lead survey to act. And philanthropy is moving, fast, toward accountability for impact. Organizations that can't show clear cost-effectiveness will struggle in the next decade. The ones that can will define the field.