Developing the Sampling Strategy

IH&S 725 Dr. Myers, C.I.H.

Developing the Sampling Strategy

Lecture Notes

IH&S 725 Dr. Myers C.I.H.

Purpose and goal of the sampling strategy

Accurately and as completely as possible document worker exposure profiles, control equipment performance, environmental release, etc


Outcomes of developing a good sampling strategy

You will Collect exposure data suitable for your needs Reduce chances of unnecessary, wasteful

sampling Produce sampling data that is representative

and accurately analyzed Develop recommendations based upon sound

data analysis


Key steps to develop and conduct the sampling strategy

1. Recognition of potential exposures by agent and worker group to form SEG.

2. Develop basis to prioritize evaluation

3. Selection of instruments and analytical methods to do the evaluation

4. Quality assurance of sampling and analytical instruments


Key steps to develop and conduct the sampling strategy

5. Determine sample parameters consistent with the purpose and scope of the survey

6. Data reduction and interpretation suitable for and consistent with the stated purpose of the survey

IH&S 725 Dr. Myers, C.I.H.

Developing the basis to prioritize evaluation


Use of risk assessment principles

Risk assessment is a multidimensional problem exposure levels, health consequences of over

exposure, whether the risk is voluntarily accepted, whether the perception is that alternate risks are higher, the immediacy of consequences if the risk is accepted, and who is at risk


Use of risk assessment principles

Two parameter generally suffice to manage an occupational air sampling strategy Exposure ranking and Health effect ranking

Sometimes the number of workers potentially exposed is also an important parameter


Exposure ranking

Exposure ranking is a monotonic semi- subjective scale available air sampling data, and or on process models that predict both airborne

concentrations and their frequency of occurrence

Scale can be defined for each agent


Health effects ranking

Based on the consequences of exposure to the agent

Constructed on a semi-subjective scale Scale can be tailored to fit different situations


Example 1 of an exposure ranking scheme based on level of control

Rank Exposure Description

Classification Basis

0 None/trivial work with closed systems

1 Low infrequent exposure under controlled conditions, such as work in a lab hood, handling small amounts of material

2 Moderate sporadic exposure with ventilation

3 High exposure to an open process such as material loading, unloading

4 Very high uncontrolled exposures, such as sand blasting, chipping and grinding of paint


Example 2 of an exposure ranking scheme based on level of the OEL



0 None/trivial Observed or potential exposure < 10% of the OEL

1 Low Observed or potential exposure < the AL or 50% of the OEL

2 Moderate Frequent exposure at concentrations below the AL or infrequent exposure at concentrations between the AL and OEL

3 High Frequent exposure at concentrations near the OEL or infrequent exposure at concentrations > the OEL

4 Very high Frequent exposure at concentrations > the OEL


Example 1 of a health effects ranking scheme



0 None/trivial nuisance materials e.g., non toxic dust

1 Low little effect, transient irritation

2 Moderate reversible, non-serious effects e.g. eye irritation

3 High non-reversible serious effects e.g. corrosives, sensitizers, etc….

4 Very high Chronic effects or fast acting life threatening chemicals e.g. carcinogens, cyanides, etc….


Example 2 of a health effects ranking scheme



0 None/trivial No known permanent health effects; no treatment needed; no sick leave involved

1 Mild Reversible health effects with suspected consequences; medical treatment usually not required; sick leave seldom needed

2 Serious Severe reversible health effects; medical treatment needed for recovery; sick leave or lost time involved

3 Critical Non-reversible health effects; not treatable; new life style required to adapt to the disability

4 IDLH Life threatening or totally disabling injury or illness


Sampling priorities: Example 1

Based on of the exposure ranking and the health effects ranking scales

can very low/trivial, low, medium, high or very high


Sampling priorities: Example 2

Health Effect Sampling Priority

4 M H H VH VH

3 L M H H VH

2 L M M H H

1 T L M M H

0 T T L L M

Exposure 0 1 2 3 4


Resource allocation: example budget proportions for assessment & control

Risk Budget Sampling Intervention

Very high 55% 11% 44%

High 24% 5% 19%

Moderate 12% 3% 9%

Low 6% 2% 4%

Very low 3% 1% 2%

Developing the Sampling Strategy

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