Economic risk describes the statistical likelihood of making a positive return on a financial investment. Perceived risk is based primarily on emotional response to a perceived threat. Perceived risk is greatly affected by such things as whether a hazard is voluntary, familiar, the time lag until an effect is noticed, whether the compound is a natural or man-made source, and whether the person at risk is the one to benefit from the source of the risk. Although risk assessment can estimate the degree of risk a chemical presents, risk assessment can't tell a person whether or not the risk is acceptable. That can only be determined by balancing the risk with its expected benefits.
People routinely accept some risks because the benefits are clear.
Some examples are driving a car and child immunization. Drinking water contamination presents a more complicated picture. Oven cleaners, furniture polishes, bathroom drain openers, paint and paint thinners, paper and ink, and countless other products contain chemicals that can turn up in drinking water if the products are not properly manufactured, used, and disposed. Every time you dry-clean clothes, put gas in the car, or buy fruits and vegetables undamaged by insects, you make use of products and services that use potentially hazardous substances. An important question in balancing risks and benefits is whether the people experiencing the risk also experience the benefits.