Bunker Hill Smelter Fire Leads to Worst Corporate Lead Poisoning in U.S. History

On September 3, 1973, a fire destroys the baghouse pollution control system at the Bunker Hill lead smelter in Kellogg, Idaho—then the largest smelting facility in the world. In a secret board meeting, Gulf Resources & Chemical Corp., the facility’s owner, makes a calculated decision to continue operating the smelter without repairing the filtration system, choosing profit over public health. Rather than shutting down for repairs, Gulf Resources determines that rising lead prices make it financially advantageous to operate without pollution controls, despite already knowing that area children had elevated blood lead levels.

For the next 11 months until August 1974, the crippled smelter pours an average of 73 tons of lead each month into the surrounding Silver Valley communities of Kellogg and Smelterville—compared to 8.3 tons per month from 1955 to 1964. Gulf Resources actually increases production during this period to take advantage of higher metal prices, with lead emissions reaching 35.3 tons per month. Over the year, 30 tons of lead per square mile is deposited on nearby neighborhoods. Internal company documents later reveal a two-page memo in which Gulf Resources’ vice president calculates how much the company would have to pay if it continued exposing children to lead rather than repair the baghouse—estimating $6 to $7 million for poisoning 500 children.

When testing begins after the smelter finally shuts down in 1974, health officials discover the worst lead poisoning event in United States history. Ninety-nine percent of children living within a mile of the smelter—173 out of 175 children tested—have blood lead levels of 40 micrograms per deciliter or higher, when just 5 micrograms is cause for serious concern. Doctors ultimately identify 197 children with dangerously elevated blood-lead levels, the highest levels ever recorded in the nation. Residents remember “the taste of metal in your teeth” from living in the contaminated zone.

The Bunker Hill disaster becomes the catalyst for listing the Coeur d’Alene Basin as a Superfund site in 1983, eventually covering over 1,500 square miles across northern Idaho and eastern Washington—one of the nation’s largest and most complex environmental cleanup sites. Since the late 19th century, mining companies had dumped over 140 million tons of ore waste directly into the Coeur d’Alene River, with approximately 2,200 tons of mine waste poured into the South Fork daily until 1968. The contamination devastates the traditional subsistence fishing grounds of the Coeur d’Alene Tribe and creates wetlands that biologists call “killing fields” where lead paralyzes the swallowing mechanisms of migrating tundra swans.

Legal action eventually brings settlements totaling over $700 million from Hecla Mining Company ($263.4 million in 2011) and from the ASARCO bankruptcy ($435 million), funding ongoing cleanup efforts that will continue for decades. The Bunker Hill case exemplifies a pattern of corporate mining operations prioritizing profit over worker and community health, relying on weak regulatory enforcement, and externalizing massive environmental and public health costs onto local communities—particularly in the extractive industries that dominated Idaho’s political economy throughout the 20th century.