Simply stated, this is a process of carefully examining a possible risk and determining how serious it is. Unfortunately, while the idea can be simply expressed it is often very difficult to carry out. Thus, answers to the direct questions that we started with are commonly complex and uncertain. Uncertainty starts with the incomplete and sometimes inconsistent information that goes into the risk assessment. The toxicity is an unchangeable characteristic of each chemical but exposure can vary tremendously from day to day.
Exposure is the only variable that humans can manage to reduce risks from toxic compounds.
That is, while humans cannot change the inherent toxicity of a chemical, they can find ways to reduce human and environmental exposure to these materials, such as installing air scrubbers, banning production of PCBs, and advising people not to eat certain fish from certain waters. Determining Toxicity Measuring toxicity would appear to be the simplest part of the assessment. There are several alternatives to human experimentation. One is to study animals that are similar to humans in some ways. While the animals are similar to humans because they are mammals, they are clearly different in many ways including, in some cases, the way they respond to toxic chemicals.