Let's say EVERYTHING causes cancer. It's the amount that will trigger it.
When we fished in Canada every year, Dad ALWAYS made us wear a hat and a life jacket.
Your Dad was wise. I have gone to Canada on fishing trips for close to 40 years. The worst time to go is late spring and early summer. That is the time the big fish are on the prowl in shallow waters. The bugs and weather can be really bad. After about 20 years we figured out late July and early August was the best time to go. Virtually no bugs and the fishing was just as good if one fished a little deeper. The drawback is can be very hot during midday on occasions.
Some say mother’s milk is bad because it can contain cancer cells.