26. Living in a polluted area

Yes, even the simple act of breathing in a polluted area can increase your cancer risk. According to the World Health Organization as cited by the American Cancer Society, the cancer-causing substances in the air caused 223,000 deaths from lung cancer in 2010 alone. In addition, pollution has also been linked to an increased risk of bladder cancer.
27. Not wearing sunscreen

Most people think they don’t need to wear sunscreen unless they’re going to the beach. But this misinformation is leading to a whole lot of skin cancer cases. According to the Skin Cancer Foundation, you should slather on SPF year-round—no matter the season or the weather—to decrease your risk.
28. Flying frequently

Not many people are on airplanes right now—and that could be a good thing. Flying too often exposes passengers to high levels of UV radiation, so it makes sense that frequent flyers are putting themselves at serious risk of skin cancer. This prolonged risk was scientifically proven by a 2015 study published in JAMA Dermatology, which found that at 30,000 feet, the UV levels are twice that of those on the ground.
29. Tanning

According to the American Academy of Dermatology, even one trip to the tanning salon can “increase users’ risk of developing melanoma by 20 percent, squamous cell carcinoma by 67 percent, and basal cell carcinoma by 29 percent.” So, for the sake of your health, it’s better to skip this venture altogether.
30. Sleeping with your phone next to your head

Though you might like falling asleep to your favorite podcast, you should make sure to get your phone as far away from your head as possible while you’re sleeping. In 2017, the California Department of Public Health came out with guidelines to minimize people’s exposure to the radio-frequency energy cell phones release, which has been linked to brain cancer. Among their suggestions was “keeping the phone away from the bed at night.”