Lifetime Average Daily Dose

What is this formula?

The Lifetime Average Daily Dose (LADD) estimates the average daily exposure to a chemical or contaminant over an individual's lifetime.

When to use it

Use this formula in human health risk assessments when exposure occurs during only part of a lifetime but risk must be evaluated over the entire lifespan.

Example

A worker is exposed to a contaminant with a chronic daily intake of 0.05 mg/kg/day for 25 years.

Data:

CDI = 0.05 mg/kg/day

ED = 25 × 365 = 9125 days

AT = 70 × 365 = 25550 days

Formula:

LADD = (CDI × ED) / AT

Substitution:

LADD = (0.05 × 9125) / 25550

Result:

LADD = 0.0179 mg/kg/day

Applications

- Human health risk assessment

- Environmental toxicology

- Carcinogenic risk evaluation

- Regulatory exposure studies

- Public health investigations

Note

This formula represents an exposure averaging model rather than a physical law. Regulatory agencies may use different averaging times, commonly 70 years for carcinogenic risk assessment. Alternative methodologies may exist depending on national regulations and exposure scenarios.