Comedian Jon Stewart made a surprise return to "The Daily Show" on Monday to once again call attention to the health care concerns of 9/11 first responders who helped with the rescue and recovery efforts at the World Trade Center site after the terrorist attack in 2001. Many of those people now face chronic health problems as a result of their exposure to toxic chemicals. They've depended on funding from Congress to help them with health care costs, but Congress has not made that funding permanent.

The James Zadroga 9/11 Health and Compensation Act was passed by Congress in 2010. But portions of the act expired after Sept. 30, and the rest of it will expire in October 2016 if the act is not renewed, according to the New York Times.

Sitting down with current host Trevor Noah, Stewart explained how important it is for the government to keep the act alive.

"It expired in September. It's soon going to be out of money. These first responders — many sick with cancers and pulmonary disease — have had to travel at their own expense to Washington, D.C. hundreds of times to plead for our government to do the right thing," Stewart said.

But Congress has been slow to renew the law due to budget concerns, something Stewart revealed in a video package to "The Daily Show" audience that shows him and first responders visiting the offices of different government officials. Stewart has been especially critical of Senate Majority Leader Mitch McConnell (R-Ky.).

"He is the key to getting this done, and so far he has been an enormous obstacle unwilling to move the bill forward for purely political reasons," Stewart said. "The only conclusion I can draw is that the people in Congress are not as good as people who are first responders."

Last week, Stewart, together with hundreds of first responders and supporters of the bill, gathered in Washington, D.C. to call out the government's failure to act.

Stewart has been dedicated to the issue for a long time. While he was host of "The Daily Show," he spent a full episode on this issue. And this past September, Stewart made his first visit to Washington with 9/11 first responders.