In 2000, Northrop Grumman was designated a Primary Responsible Party under federal Superfund laws at 13 hazardous waste sites and under state Superfund laws at eight sites. The corporation has also been linked to 52 superfund toxic waste sites. Based on 2008 data, Northrop Grumman was the 62nd-largest corporate producer of air pollution in the United States, per the Political Economy Research Institute of the University of Massachusetts Amherst. Northrop Grumman facilities released more than 23,798 pounds of toxic chemicals into the air in that year.