The site of a former lead and zinc mine in Kabwe, Zambia. Thirty years after the closure of the mine, the land remains highly contaminated — and artisanal miners continue to work here, exposing themselves daily to dangerously high levels of lead. Tommy Trenchard for NPR hide caption

Fishermen from the Vezo community have become "ocean monitors." Above: They're diving around a coral reef in Madagascar's Barren Isles to collect data that can be used to assess ocean health and improve conservation efforts. Julie Bourdin hide caption