Asbestos as well as other airborne carcinogens and genetics are also linked to lung cancer.
There is no evidence linking steroids to testicular cancer.
http://www.mdanderson.org/diseases/...8d5f-11d4-80f800508b603a14&method=displayfull
"Risk factors for testicular cancer include:
Age: testicular cancer is most common in adolescents and young adults up to age 40. It is the most common form of cancer in young men.
Family history: if a man has testicular cancer, his male relatives are at increased risk.
Cryptorchidism: a condition in which one or both of the testicles fail to descend from the abdomen into the scrotum during infancy. Cryptorchidism is associated with about 14% of testicular cancer cases.
Prior cancer history: a man who has had cancer in one testicle has a higher risk of getting it in the remaining testicle than someone who's never had testicular cancer.
Other possible risk factors include the human immunodeficiency virus (HIV), injury to the testicles and vasectomies, but to date, studies have not found a clear association between these conditions and testicular cancer. "