KEN WAMSLEY SOMETIMES DREAMS that he’s playing softball again. He’ll be at center field, just like when he played slow pitch back in his teens, or pounding the ball over the fence as the crowd goes wild. Other times, he’s somehow inexplicably back at work in the lab. Wamsley calls them nightmares, these stories that play out in his sleep, but really the only scary part is the end, when “I wake up and I have no rectum anymore.”

Wamsley is 73. After developing rectal cancer and having surgery to treat it in 2002, he walks slowly and gets up from the bench in his small backyard slowly. His voice, which has a gentle Appalachian lilt, is still animated, though, especially when he talks about his happier days. There were many. While Wamsley knew plenty of people in Parkersburg, West Virginia, who struggled to stay employed, he made an enviable wage for almost four decades at the DuPont plant here. The company was generous, helping him pay for college courses and training him to become a lab analyst in the Teflon division.

He enjoyed the work, particularly the precision and care it required. For years, he measured levels of a chemical called C8 in various products. The chemical “was everywhere,” as Wamsley remembers it, bubbling out of the glass flasks he used to transport it, wafting into a smelly vapor that formed when he heated it. A fine powder, possibly C8, dusted the laboratory drawers and floated in the hazy lab air.

At the time, Wamsley and his coworkers weren’t particularly concerned about the strange stuff. “We never thought about it, never worried about it,” he said recently. He believed it was harmless, “like a soap. Wash your hands [with it], your face, take a bath.”

Today Wamsley suffers from ulcerative colitis, a bowel condition that causes him sudden bouts of diarrhea. The disease also can — and his case, did — lead to rectal cancer. Between the surgery, which left him reliant on plastic pouches that collect his waste outside his body and have to be changed regularly, and his ongoing digestive problems, Wamsley finds it difficult to be away from his home for long.

Sometimes, between napping or watching baseball on TV, Wamsley’s mind drifts back to his DuPont days and he wonders not just about the dust that coated his old workplace but also about his bosses who offered their casual assurances about the chemical years ago.

“Who knew?” he asked. “When did they know? Did they lie?”