But he ended up described by the New York Times as "the lawyer who became DuPont's worst nightmare", after exposing the corporation for a decades-long history of chemical pollution.
He is joined on a Global water crisis panel on Saturday by Kye Gbangbola, who lost his seven-year-old son Zane and suffered paralysis caused by hydrogen cyanide after his Chertsey home was flooded in 2014.
Also speaking on the 7pm panel is BBC investigative journalist Leana Hosea, who directed the award-winning film Thirst for Justice.
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