The Question

Read the following carefully and then answer the QUESTION.

Only 5–10% of all cancer cases can be attributed to genetic defects, whereas the remaining 90–95% have their roots in the ENVIRONMENT and LIFESTYLE.

Our skin(outside/epidermis) covers an average area of 18.75 square feet. Our gastrointestinal tract which makes up the rest of the humans environmentally exposed surface area covers an average area of 377 square feet.

Our GI tract which is twenty(20) times larger than our external world is just one thin and very delicate layer of dermis compared to our external environment which is made up of an incredibly durable five(5) layers that can withstand all manner of insult and injury.

The average human consumes 1,750 pounds of food per year passing over/through that tract, which is actually external though most consider it internal. In actuality, the inside of our body doesn’t start until the small intestine.

QUESTION: According to the aforementioned information, what is the single greatest cause of environmentally caused cancer based on exposure and lifestyle choices?