The Tsumeb smelter shutdown in Namibia has been extended to 40 days, owing to Covid-19-related safety protocols, travel restrictions and an increase in the scope of maintenance work. The shutdown ...

Emissions of hazardous air pollutants from Asarco’s Hayden smelter, about 70 miles north of Tucson, led to an EPA dust control plan. Kelly Presnell / Arizona Daily Star 2019 ...

But the company reporting the most releases said its estimate is erroneously high, though it hasn't provided new numbers.