Jon Stewart speaks during a press conference about the Sergeant First Class Heath Robinson Honoring Our Promise to Address Comprehensive Toxics Act of 2022 in Washington. Getty Images / AFP
Stewart has long advocated for causes he believes in. Getty Images / AFP
Stewart hugs 9/11 advocate John Feal. Getty Images / AFP
Stewart has been championing causes for veterans for many years. Getty Images / AFP
Senator John Tester and Stewart embrace. Getty Images / AFP
Air Force veteran Tim Hauser speaks during Thursday's press conference. Getty Images / AFP
An Afghan National Army pickup truck passes a fire in a trash burn pit south of Kabul, Afghanistan. AP
Senator Kirsten Gillibrand addresses a news conference about military burn pits legislation outside the US Capitol in March. Getty Images / AFP
Stewart poses for a photograph with Lauren Grigsby, Charlotte Brock and Melinda Beyer whose friend, Marine Corps veteran Kate Hendricks, died after being exposed to burn pits. AFP
Danielle Robinson, widow of Ohio Army National Guard veteran Health Robinson, who died in 2020 due to lung cancer caused by burn pits, addresses the crowds. Getty Images / AFP
Stewart talks with Ms Robinson outside the US Capitol in March. Getty Images / AFP
Brielle Robinson, daughter of the late Army Sgt First Class Heath Robinson outside the US Capitol in March. Getty Images / AFP
Congressman Raul Ruiz joins veterans, advocacy groups, activists, victims' families and fellow Democrats for a news conference about military burn pits legislation. Getty Images / AFP
Stewart, a long-time New Yorker, also advocated for 9/11 victims. Getty Images / AFP
Trash at a burn pit in Forward Operating Base Zeebrudge, Helmand province, Afghanistan. US Marines / AFP
Burn pits are commonly used by the US military to get rid of everything from plastic bottles to human waste to old tyres – all incinerated with the aid of jet fuel. US Marines / AFP
Speaker of the House Nancy Pelosi at a news conference at the US Capitol in March. Getty Images / AFP