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Developing the Sampling Strategy. Lecture Notes. 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 - PowerPoint PPT Presentation
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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
IH&S 725 Dr. Myers C.I.H.
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
IH&S 725 Dr. Myers C.I.H.
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
IH&S 725 Dr. Myers C.I.H.
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
IH&S 725 Dr. Myers C.I.H.
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
IH&S 725 Dr. Myers C.I.H.
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
IH&S 725 Dr. Myers C.I.H.
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
IH&S 725 Dr. Myers C.I.H.
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
IH&S 725 Dr. Myers C.I.H.
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
IH&S 725 Dr. Myers C.I.H.
Example 2 of an exposure ranking scheme based on level of the OEL
Rank Exposure Description
Classification Basis
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
IH&S 725 Dr. Myers C.I.H.
Example 1 of a health effects ranking scheme
Rank Exposure Description
Classification Basis
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….
IH&S 725 Dr. Myers C.I.H.
Example 2 of a health effects ranking scheme
Rank Exposure Description
Classification Basis
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
IH&S 725 Dr. Myers C.I.H.
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
IH&S 725 Dr. Myers C.I.H.
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
IH&S 725 Dr. Myers C.I.H.
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%