Controversies over pollution in the smelter town of La Oroya have drawn public attention to the consequences of mining activity. By exploring the emergence of activism, changes in corporate practices, and the processes through which pollution comes to matter, this chapter situates recent conflicts over mining within national debates and historical processes. Over La Oroya’s history, toxic emissions have been variously treated as a problem of industrial hygiene and occupational health, and more recently, as an environmental and public health concern affecting local residents, the neighboring valley, and the entire watershed. La Oroya’s notoriety as one of the “world’s most...