This place is called a source. A source could be a landfill, pond, creek, incinerator, tank, drum, or factory. There are many different sources of chemicals. You could come into contact with a chemical at its source. Or, the chemical could move from its source to a place where you could come into contact with it.
Chemicals can move through air, water, and soil.
They can also be on plants or animals, and get into the foods we eat. The chemical has to get into your body to make you sick, or to have an effect on your health. But if you are not exposed to a chemical, it won t make you sick. If you are exposed, there are three ways a chemical could get into your body. This depends on a lot of factors about the exposure.