©THESTAR EXAM SOLUTIONS 2024/2025
ALL RIGHTS RESERVED.
EHS Exam 1 Study Guide.
Quanitative risk assessment (QRA) - answer✔Approach that allows the quantitative expression of risk in
terms of infection, illness, or mortality from microbial pathogens. Used by decision makers to determine
the magnitude of such risks and weigh the costs and benefits of corrective action
Risk management - answer✔Consideration of social, political and economic issues. Values and ethics.
Balance risks that discovered from risk assessment. Select best regulatory action based on results of risk
assessment
Risk communication - answer✔Component of risk management. Interactive process of information and
opinion exchange among individuals, groups, and institutions. Includes the transfer of risk information
from expert to non expert audiences
Comparative risk assessment - answer✔Comparison of potential risks associated with several problems
or issues. Example: risks from chemical exposure are small compared to those associated with driving a
car
de minimis principle - answer✔There are some levels of risk so small that they are not worth bothering
about. Hard to define. Minimus = minimal = nothing basically
Tolerable risk - answer✔Level of risks we can accept given the economic costs, and social and scientific
constraints. Lifetime risk of one in a million is small enough to be acceptable for the general public
Exposure pathway - answer✔Course that a hazardous agent takes from a source to a receptor (ex:
human or animal) via environmental carriers or media- generally air or water. Ex: ingestion of soil and
dust
Exposure route - answer✔Intake pathway. Mechanism by which the transfer occurs- inhalation,
ingestion, and/or dermal contact. Way an individual comes in contact with a toxic substance
Event trees - answer✔Estimate exposure by analysis of pathogen loads upstream when the actual
concentration of the harmful agent that reaches the target is too low to measure
Dose-response relationship - answer✔Quantitative relationship that indicates the agent's degree of
toxicity to exposed species
% Response = % affected by substance, % who respond (have effects) from dose
1|Page
, ©THESTAR EXAM SOLUTIONS 2024/2025
ALL RIGHTS RESERVED.
Dose - answer✔Milligrams of substance or number of pathogen ingested, inhaled, or absorbed through
the skin
Amount of a substance delivered at one time
Exposure dose - answer✔Amount of xenobiotic encountered in the environment
Absorbed dose - answer✔Actual amount of the exposed dose that enters the body
Administered dose - answer✔Quantity administered usually orally or by injection
Total dose - answer✔The sum of all individual doses
Response - answer✔Effects. Can vary widely- from no observable effect, to temporary and reversible
effects, etc.
Minimum infectious dose - answer✔Implies that a threshold dose exists for microorganisms. Refers to
ID50 (dose at which 50% of the animals or humans exposed became infected or exhibit any symptoms of
an illness
Uncertainty - answer✔In every step of the risk assessment process. Example: extrapolation from high to
low doses
When people tell you wrong information in survey
Variability - answer✔When survey people, don't get accurate facts
Sensitivity analyses simulation - answer✔The uncertain quantities of each parameter (ex: average
values, high and low estimates) are varied, usually one at a time, to find out how changes in these
quantities affect the final risk estimate. Gives range of possible values for the overall risk and provides
information on which parameters are most crucial in determining the size of the risk
Monte Carlo simulation - answer✔Assumed that all parameters are random or uncertain. So computer
program selects distributions randomly every time the model equations are solved
Subclinical infection (asymptomatic) - answer✔Infection (growth of microorganism in body) results in no
obvious illness (fever, headache, etc.). Individuals can host a pathogen microorganism and transmit it to
others without ever getting sick themselves
Secondary attack rate - answer✔Infection due to person-to-person contact or contact with
contaminated inanimate objects (such as toys)
Risk assessment - answer✔Estimating both the probability that an event will occur and the probable
magnitude of its adverse effects- economic, health- over a period of time
2|Page
ALL RIGHTS RESERVED.
EHS Exam 1 Study Guide.
Quanitative risk assessment (QRA) - answer✔Approach that allows the quantitative expression of risk in
terms of infection, illness, or mortality from microbial pathogens. Used by decision makers to determine
the magnitude of such risks and weigh the costs and benefits of corrective action
Risk management - answer✔Consideration of social, political and economic issues. Values and ethics.
Balance risks that discovered from risk assessment. Select best regulatory action based on results of risk
assessment
Risk communication - answer✔Component of risk management. Interactive process of information and
opinion exchange among individuals, groups, and institutions. Includes the transfer of risk information
from expert to non expert audiences
Comparative risk assessment - answer✔Comparison of potential risks associated with several problems
or issues. Example: risks from chemical exposure are small compared to those associated with driving a
car
de minimis principle - answer✔There are some levels of risk so small that they are not worth bothering
about. Hard to define. Minimus = minimal = nothing basically
Tolerable risk - answer✔Level of risks we can accept given the economic costs, and social and scientific
constraints. Lifetime risk of one in a million is small enough to be acceptable for the general public
Exposure pathway - answer✔Course that a hazardous agent takes from a source to a receptor (ex:
human or animal) via environmental carriers or media- generally air or water. Ex: ingestion of soil and
dust
Exposure route - answer✔Intake pathway. Mechanism by which the transfer occurs- inhalation,
ingestion, and/or dermal contact. Way an individual comes in contact with a toxic substance
Event trees - answer✔Estimate exposure by analysis of pathogen loads upstream when the actual
concentration of the harmful agent that reaches the target is too low to measure
Dose-response relationship - answer✔Quantitative relationship that indicates the agent's degree of
toxicity to exposed species
% Response = % affected by substance, % who respond (have effects) from dose
1|Page
, ©THESTAR EXAM SOLUTIONS 2024/2025
ALL RIGHTS RESERVED.
Dose - answer✔Milligrams of substance or number of pathogen ingested, inhaled, or absorbed through
the skin
Amount of a substance delivered at one time
Exposure dose - answer✔Amount of xenobiotic encountered in the environment
Absorbed dose - answer✔Actual amount of the exposed dose that enters the body
Administered dose - answer✔Quantity administered usually orally or by injection
Total dose - answer✔The sum of all individual doses
Response - answer✔Effects. Can vary widely- from no observable effect, to temporary and reversible
effects, etc.
Minimum infectious dose - answer✔Implies that a threshold dose exists for microorganisms. Refers to
ID50 (dose at which 50% of the animals or humans exposed became infected or exhibit any symptoms of
an illness
Uncertainty - answer✔In every step of the risk assessment process. Example: extrapolation from high to
low doses
When people tell you wrong information in survey
Variability - answer✔When survey people, don't get accurate facts
Sensitivity analyses simulation - answer✔The uncertain quantities of each parameter (ex: average
values, high and low estimates) are varied, usually one at a time, to find out how changes in these
quantities affect the final risk estimate. Gives range of possible values for the overall risk and provides
information on which parameters are most crucial in determining the size of the risk
Monte Carlo simulation - answer✔Assumed that all parameters are random or uncertain. So computer
program selects distributions randomly every time the model equations are solved
Subclinical infection (asymptomatic) - answer✔Infection (growth of microorganism in body) results in no
obvious illness (fever, headache, etc.). Individuals can host a pathogen microorganism and transmit it to
others without ever getting sick themselves
Secondary attack rate - answer✔Infection due to person-to-person contact or contact with
contaminated inanimate objects (such as toys)
Risk assessment - answer✔Estimating both the probability that an event will occur and the probable
magnitude of its adverse effects- economic, health- over a period of time
2|Page
