Joe Biden, like many other families of service members diagnosed with illnesses from overseas deployments, suspects toxic exposure may have been behind his son Beau’s brain cancer.

Beau Biden boarded a military aircraft for Iraq on Nov. 19, 2008, just days after his father became vice president-elect. He deployed with the Delaware Army National Guard to Balad Air Base, where the U.S. military burned an estimated 140 tons of waste a day in open air burn pits.

Photo credit: BY SERVICE EMPLOYEES INTERNATIONAL UNION