One of the African baseball teams at this Olympic Games couldn't even afford enough balls to train with because one ball costs the equivalent of a week's wages. Balls ceased to be 'latest technology' some time ago. The health risks seem to me to be greatly overstated but they exist. Chronic, uncontrolled use of almost anything is harmful and there will continue to be casualties given the present attitude of the authorities. But sport itself is harmful.
People die and are injured every year whilst taking part in sport.
Dehydration is a serious prospect in endurance sports at this year's Games. A competitor at Atlanta had a mild heart attack when he realised he had won a medal. If the criterion is potential health damage why was Peter Elliott, a British competitor, allowed to compete in an Olympic final, some years ago, having had a perfectly legal injection of hydrocortisone to mask the pain of a serious ankle injury. Pain is supposed to be the body's natural harm reduction mechanism. Peter Elliott in fact never really competed at the highest level again.