Carlos Cardona sifted through and cleared rubble for four days at ground zero after the Sept. 11 attacks. Little did he know that his decision to volunteer in 2001 would ripple into the future.

The exposure to toxins in the debris left him with chronic respiratory problems, with which he continues to struggle. And last month, that volunteer work led Gov. Andrew M. Cuomo of New York to pardon Mr. Cardona, an undocumented immigrant from Colombia, for a 1990 drug conviction that had put him at risk of deportation.

“For me, I feel like it was something that I had to do,” Mr. Cardona, an owner of a construction business in Queens, said, adding that he would step up again in a disaster area if he had to.

Now, Mr. Cardona’s story has prompted some Democratic members of New York’s congressional delegation to propose protections against deportation for undocumented immigrants who helped after the attacks. A bill that would grant green cards to undocumented immigrants who served in the rescue, recovery and cleanup efforts after the terrorist attacks will be introduced in the House this week, Representative Joseph Crowley, of Queens, said Sunday.