He found that at least one-fourth of the diseases in the world are caused by environmental factors like air pollution, water pollution, lack of sanitation and chemicals in the workplace — all factors that could be controlled.
“Kirk led the world to greater understanding of the environment’s outsized role in health, not the least of which was due to the burning of dirty household fuels, on which Kirk was the world’s top scholar,” Justin Remais, chair of the division of environmental health sciences at the Berkeley School of Public Health, said in an email.
In addition to identifying problems, Dr. Smith sought solutions.
He initially thought the answer to household air pollution was better cookstoves. But he came to see that replacing old stoves with new ones would take decades, particularly on the massive scale needed, and that many lives would be lost before such a transformation could take place.
Moreover, he realized, the new stoves, at least those that were affordable, would not dramatically improve health.
“He spent a lot of time thinking about and learning from the experiences of the people he was trying to help,” his daughter, Nadia Diamond-Smith, who works in global maternal and reproductive health in India and Nepal, said in an interview. He understood, she said, that if the new stoves were only marginally better, people wouldn’t use them, and that only something with more obvious benefits would make a difference.
In a major pivot, unusual for such a prominent scientist, Dr. Smith reset his goal and campaigned instead for cleaner fuels like liquefied petroleum gas, or LPG.
In India, where 700 million people relied on the old stoves, he spent years collaborating with colleagues and building relationships. He was finally able to help persuade local governments to make LPG more widely available.