working teenagers..!!

Hey guys,
My 16-year-old son wishes to be a part of window cleaning and gutter cleaning service in the region. Many teenagers are part of this to earn money to pay for their education and all. I usually encourage such initiatives from children, but I think this is too risky to do such works because gutters cleaning requires heavy labour. I'm afraid that he won't be able to handle it, and beyond that, these works will be at great heights. It will be an extremely dangerous experience. He tried to convince me that they use proper fall protection equipment and take training under professionals for using fall protection systems from Ontario. But still, I don't think it would be the right thing because he is too young. But my son keeps trying to convince me, and he deeply wishes to go for that work. What should I do? Should I allow him to go? Will it be safe? I need some suggestions. Please help me out.