FIGURE 5.1 Chili peppers dried over open, unvented, coal-burning stoves are the main pathway for chronic arsenic exposure in Guizhou Province, China.

SOURCE: Finkelman et al. (2001).

avoid those deposits that have high concentrations of toxic metalloids and compounds. Information on the modes of occurrence of potentially toxic elements, and the textural relations on the minerals and macerals in which they occur, may help scientists anticipate the behavior of the potentially toxic compounds and metals during coal use. This type of characterization offers an opportunity for geoscientists and public health professionals to directly contribute to the resolution of a major public health issue.

Arsenic-Contaminated Food in Chile

The Northern Region II of Chile has both natural and anthropogenic sources of environmental arsenic. The major river basin in this region is the Rio Loa, sourced in the highly contaminated El Tatio geyser basin where natural hot spring waters contain 30–50 mg L⁻¹ total arsenic. The Rio Loa also receives arsenic from runoff waters and airborne emissions due to extensive copper mining activities in the region.

Crops grown in the village of Chiu Chiu have substantially elevated levels of arsenic and, depending on the arsenic load in the drinking water, food represents 4–25% of the total arsenic intake. The arsenic principally occurs as inorganic As⁺³ and As⁺⁵ and carrots, for example, preferentially take up the most toxic As⁺³. While the level of arsenic in the food crops of this region is generally below Chile’s regulatory limits, concentrations are significantly higher than would typically be found in foods in other regions and represent a significant component of the total arsenic intake by local inhabitants.