A bipartisan group of legislators has asked President Donald Trump to make more money available for black lung health clinics as they face an increase in cases of the disease among coal miners.

More than 20 clinics would benefit from the $3.3 million increase lawmakers are requesting. The clinics provide miners with health screenings, medical care, and assistance in securing black lung benefits.

The lawmakers wrote in a letter to the president and the White House budget director that the level of funding for clinics has been frozen for the past five years.

“Some clinics are so underfunded that they are operating with obsolete and inefficient diagnostic equipment,” they wrote.

According to a study by the National Institute of Occupational Safety and Health there’s been a surge of coal miners with severe cases of black lung. An investigation by NPR found nearly one thousand cases of advanced black lung disease diagnosed at eleven clinics over the past decade.

The legislators from Ohio, Pennsylvania, Virginia and West Virginia urge Trump to consider the demand on black lung health clinics. The requested increase would bring total funding to $10 million.

This story was originally published by Ohio Valley ReSource.