Where are people exposed to chemicals?
Well, what are we breathing right now..........?
You are breathing in dinitrogen and dioxygen. You exhale dinitrogen and carbon dioxide. And the atmosphere contains traces of other gases.
You drink water.
You have a wash with water, and soap. You eat carbohydrates and proteins.
You ride to work on a vehicle powered by hydrocarbons, which spits out carbon dioxide exhaust fumes, and also some nitrogen oxides.
And so your exposure to chemicals is pervasive, and unavoidable.