As human beings, maintenance of our physical bodies unequivocally requires a few core ingredients from our environment. To survive, we must eat food to get glucose for cellular functioning, drink water to stay hydrated and maintain osmotic pressure, and breathe to acquire oxygen and discharge waste gases. Given this dependence on food, water, and air, we should be on the lookout for unintentional exposures through ingestion and respiration that could support or harm our health.
In the industrialized world, finding information on the ingredients of food is fairly easy and sometimes impossible to ignore, as in the case of the calorie count of a chocolate chip cookie from Starbucks. The compounds in water are also easily discovered by reading the fine print on a bottle label or testing your potable water.