Some unsuspected sources are:
Chronic Inflammation - sugar & grains
Pesticides (in foods)
Chemical from aerosol cans
Grante counter tops (emits radon)
Canola Oil (omega-6)
Soy and soy based products - unless it's fermented such as natto. 91% of soy grown in the U.S. is GMO to resist herbicides. Soy based formula contains a daily dose equivalent of 5 birth control pills of estrogen.
Tap Water - Chlorine and Flouride (in many municiple water supplies).
Other known agents are:
Most cancer is not born, but made.
Sources & References: