This city of almost 300,000 people, 80 miles north of Zambia's capital of Lusaka, was identified by a 2022 U.N. report as a "sacrifice zone" — one of the most polluted places on the planet. Between 1906 and 1994, Kabwe was home to Broken Hill, one of the world's largest lead and zinc mines. For decades, highly toxic lead particles were blown across town, carried by the wind and the waterways, contaminating the soil in courtyards, playgrounds and on dirt roads where speeding trucks raise plumes o