Researchers led by Carlos Manzano of the Universidad de Chile's Faculty of Sciences analysed surface soil from seventeen points across Arica, the port city near Chile's border with Peru, and found elevated concentrations of potentially toxic elements, principally lead, zinc and arsenic. Maximum values reached 47 milligrams per kilogram of arsenic, 487 of lead and 1,740 of zinc, with some concentrations exceeding international reference values. The study appeared in the journal CLEAN Soil, Air, Water.
The work began as the undergraduate thesis of environmental chemist Diego Ayala, himself an Arica native, which lends the findings a personal edge. Part of the contamination plausibly traces back to roughly 20,000 tonnes of Swedish mining waste dumped in the city in the mid-1980s, the notorious polymetals case that has shadowed Arica for four decades, though the authors note that contemporary urban and industrial sources may also contribute. Hotspots clustered at three specific street intersections.
The researchers are explicit about what the study does not show: metals were measured in soils, not in people, and no link to disease was established. But they argue the persistence of legacy contamination demands bioaccessibility testing and sustained environmental and health monitoring. Chile, they point out, still lacks a binding national standard for contaminated soils, a regulatory gap that leaves cities like Arica relying on ad hoc responses to industrial inheritance.