CIH CIH - Certified Industrial Hygienist Sampling Strategy and Statistical Analysis Questions and Answers

Question 1

According to AIHA strategy guidelines, what is the primary purpose of a baseline survey in an industrial hygiene program?

Accepted Answer

To characterize exposures and assign workers to similar exposure groups (SEGs)

Answer

To immediately identify all overexposures

Answer

To satisfy OSHA recordkeeping requirements only

Answer

To determine the need for administrative controls

Question 2

What statistical distribution is most commonly assumed for occupational exposure data when performing lognormal analysis?

Accepted Answer

Lognormal distribution

Answer

Normal (Gaussian) distribution

Answer

Poisson distribution

Answer

Binomial distribution

Question 3

What does the geometric standard deviation (GSD) indicate in occupational exposure data analysis?

Accepted Answer

The spread or variability of a lognormal exposure dataset

Answer

The average exposure concentration across all measurements

Answer

The ratio of the 95th percentile to the OEL

Answer

The minimum number of samples required for statistical validity

Question 4

In the AIHA exposure assessment strategy, what is the recommended minimum number of samples per SEG for a statistically defensible assessment?

Accepted Answer

6 samples

Answer

3 samples

Answer

10 samples

Answer

25 samples

Question 5

What is the upper confidence limit (UCL) used to determine in occupational exposure assessment?

Accepted Answer

Whether the true 95th percentile exposure likely exceeds the OEL

Answer

The lowest expected exposure in a group

Answer

The arithmetic mean of all sample results

Answer

The time-weighted average for the longest shift

Question 6

Which sampling approach should be used when a worker performs multiple tasks with different exposure levels throughout the day?

Accepted Answer

Task-based sampling with time-weighted averaging

Answer

A single full-shift sample only

Answer

Worst-case instantaneous grab sampling only

Answer

Passive badge sampling at one location