The amount of a substance to which a person is exposed over some time period. Dose is a measurement of exposure. Dose is often expressed as milligram (amount) per kilogram (a measure of body weight) per day (a measure of time) when people eat or drink contaminated water, food, or soil. In general, the greater the dose, the greater the likelihood of an effect. An \exposure dose\ is how much of a substance is encountered in the environment. An \absorbed dose\ is the amount of a substance that actually got into the body through the eyes, skin, stomach, intestines, or lungs.