Non-Discrete Composite Sampling EPC Calculations

EPC Guidance Depending on Exposure Duration

Acute Exposures

ATSDR recommends examining the appropriateness of using composite sampling data to evaluate acute exposures on a case-by-case basis. You must be sure that a composite sample truly represents only the area where one might have exposure over an acute duration. Refer to the Non-Discrete Sampling EPC Guidance, and contact the ADS group for help, if needed.

Intermediate or Chronic Exposures

Single composite sample: Use if you determined it accurately represents the exposure unit. But acknowledge any uncertainty (referring to when information is incomplete or unknown) with its use in your report.
Multiple composite samples: Determine whether each composite sample represents an equal size area of the exposure unit.
- Unequal size: Use a weighted average of the composite samples as the EPC.
- Equal size: Use an average of the composite samples as the EPC.

In the next section you will learn about the EPC guidance for non-discrete incremental sampling method data EPC calculations.