TAMPA, Fla. (WFLA) —Long-awaited aid for U.S. veterans exposed to toxic burn pits is heading to President Joe Biden’s desk.

The legislation known as the PACT Act is expected to provide billions of dollars in aid for an estimated 3.5 million troops who were exposed to toxic burn pits during their service.

During wars in Iraq and Afghanistan, the U.S. military disposed of medial waste and raw sewage in the pits.

Many veterans say, as a result, they’ve developed medical issues such as respiratory problems and cancer.

They claim the Department of Veteran Affairs has been denying their medical claims because the issues cannot be definitively linked to toxins from the burn pits.

Under the PACT Act, veterans are no longer required to prove the medial ailments are caused by the pits.

Additionally, it covers former military members exposed to Agent Orange during the Vietnam War.

The bill’s passage ends a standoff in Senate where Republicans blocked the legislation last week.

Veterans have protested outside the Capitol since last Thursday.

President Biden is expected to sign the PACT Act into law.