Bioavailability factor for improved drinking water contaminant exposure risk assessment accuracy

Area of Science:

• Environmental Chemistry
• Toxicology
• Public Health

Background:

• Drinking water contains diverse chemical constituents at low concentrations.
• Current risk assessments primarily use exposure and toxicity data.
• Limited chemical retention in the body affects assessment accuracy.

Purpose of the Study:

• To propose incorporating a bioavailability factor (F) into drinking water risk assessments.
• To enhance the accuracy of chemical-mediated human health risk calculations.
• To refine regulatory approaches for drinking water contaminants.

Main Methods:

• Introduced a bioavailability factor (F) representing the ratio of a compound in circulation and excretion.
• Demonstrated F value application using disinfection by-products (DBPs).
• Considered multivariable specificity, including exposure route and gender.

Main Results:

• The bioavailability factor (F) accounts for biological retention ratios.
• Incorporating F improves the accuracy of human health risk assessments.
• This approach offers leniency for less bio-retained chemicals.

Conclusions:

• The proposed bioavailability factor (F) refines drinking water risk assessment.
• This method has implications for controlling emerging pollutants.
• Updated national drinking water standards can be informed by this approach.