Smoking
Though the tobacco industry tried to cover this one up, we’ve known for years that tobacco smoke has at least 70 cancer-causing chemicals inside. And it’s not just smokers who are affected – people who inhale secondhand smoke can develop deadly forms of cancer too.
Unprotected sun exposure
According to the Skin Cancer Foundation, people who use a tanning bed before age 35 increase their risk of developing melanoma by 75%. Regular sun can hurt you too, so wearing protective clothing and sunscreen and finding shade are good ideas if you’re going to be out in the sunshine for more than 15 minutes.