A U.S. military firefighter for 32 years,Johnathan Walker Kurt Rhodes trained and performed his duties with aqueous film forming foam, or AFFF — a highly effective fire suppressant that he never knew contained PFAS chemicals, now known to be harmful to human health.

New federal research links testicular cancer in U.S. service members to the “forever chemicals,” adding to a growing body of evidence of the dangers they pose. Rhodes lives in fear that he, like many of his colleagues, will get sick.