U.S. Sen. Raphael Warnock is promoting his support for a new law that expands medical benefits for veterans who were exposed to toxic open-air burning pits of trash on U.S. military bases.

The Democrat launched a TV ad Friday that features Adam Tomblin, a Marine Corps veteran who praises Warnock for backing legislation that expands benefits for servicemembers exposed to fires at military bases where chemicals, electronic equipment and other toxins were burned.

“We were there to serve our country, but in the process we were exposed to toxic chemicals and denied proper care when we got home,” said Tomblin. “But Raphael Warnock has changed things. He helped pass a law to expand healthcare for tens of thousands of Georgia veterans.”

Biden signed the legislation into law after a yearslong effort by veterans and their loved ones to make it easier for those who were exposed to the poisons to secure medical benefits. Known as the PACT Act, it sets aside $280 billion in federal funding for additional veterans benefits.

It withstood late opposition from some Republicans who initially tried to halt its passage before reversing course after stiff backlash. GOP Senate nominee Herschel Walker, Warnock’s November opponent, has said he would have backed the measure.