3. Birth Control and Estrogens
According to the National Cancer Institute, women who begin menstruating at an early age, go through menopause late, are older at first pregnancy, or never have given birth have an increased risk of breast cancer because they are exposed to more estrogen and progesterone made by the ovaries. Women who are going through menopause and use a combined estrogen-progestin therapy to help ease symptoms may also be at a greater risk of developing breast cancer. Using birth control pills can increase a woman’s risk of developing cervical cancer, although there is some evidence that suggests that being on birth control is associated with a reduced risk of developing other types of cancers, such as endometrial (uterus), colorectal, and ovarian.
Contracting various types of viruses can increase your risk of cancer. This is due to the viruses triggering changes in cells that can result in cancer. “Some viruses linked to cancer are the human papillomavirus (HPV), which causes cervical cancer; hepatitis B and C viruses, which can cause liver cancer; and the Epstein-Barr virus, which may cause a type of lymphoma. Also, the H. pylori bacterium can cause gastric cancer,” according to the CDC.
1. Disaster Sites
Breathing in air that is infused with toxic fumes for long periods can also be a great cancer risk. Scientists have studied New York City firefighters, office workers, and students who returned to downtown Manhattan in the days following the 9/11 attacks and found that they consistently have higher rates of 70 different types of cancers, including breast, cervical, colon, and lung cancers. Also, people who lived near the site of the 1986 nuclear disaster of Chernobyl in Ukraine have developed higher-than-usual rates of lung and thyroid cancers, as well as leukemia.Related: 9 Symptoms That Could Be Warning Women of Cancer