What’s Involved in a Toxicologic Evaluation?

Toxicologic evaluations are conducted to find out whether people are contacting chemicals at levels that can hurt them.

ATSDR has developed the following key steps for conducting a toxicologic evaluation.

Step 1.
For each chemical selected for further evaluation, estimate the amount of the chemical that would enter a person’s body (this is called the exposure dose).  The estimate is based on how the chemical gets into the body.

Step 2.
Compare the estimated exposure doses to health guidelines to determine which exposure doses need more evaluation.

Step 3.
Use results of previous studies of humans and animals to judge the likelihood for health effects to result from the specific exposures investigated.

Why is knowing about toxicology important for community members?

A chemical will only cause harm after a certain amount of the chemical has been absorbed into a person’s body. Toxicologists often say, “it’s the dose that makes the poison.” Learning about toxicology can help community members better understand health risks and therefore enable them to make better decisions to protect their health and quality of life.

Do health assessors conduct the toxicologic evaluation themselves?

Depending on the specific toxicologic issues at a site, health assessors can conduct toxicologic evaluations themselves or call upon ATSDR toxicologists for assistance. These toxicologists have extensive training and experience in interpreting toxicity information. Senior scientists review the results of all evaluations.