Environment: Grim Days for El Paso

Ever since the 1880s, the clean desert air over El Paso has been smudged black from smokestacks belonging to the American Smelting & Refining Company. El Pasoans sneezed and coughed, but the belchings seemed a necessary nuisance to most people—and particularly to the plant's 750 workers, largely Mexicans, who earned their livelihood by smelting copper and lead.

Now they are beginning to wonder. Early this month five youngsters who live near the plant had to be hospitalized for severe lead poisoning. They were two to five years old. "Blood samples showed basophilic stippling [small purple dots], and some of the children showed...