My husband was Facility Manager at our church for 25 years, and I think it was his use of Round-Up when he took care of the grounds. He would wear a backpack of the stuff and spray it around the area. One time the backpack had a leak, and it wet his entire back, but he was unaware of it until he was done. I think that chemical compound seeped into his skin. He was athletic and very healthy....UNTIL his MDS/AML diagnosis in 2023. He is 74.