Risk Assessment

EPA Group E

No evidence of carcinogenicity in humans.- at least two adequate animal tests or both negative epidemiology and animal studies.

EPA Group C

Possible Human Carcinogen - inadequate evidence in animals

EPA Group B1

Probable Human Carcinogen - limited evidence in humans

What is risk communication?

Risk assessment and risk management data is transfered to the public, lay groups, environmentalists

What is a Risk?

The PROBABILITY that the HAZARD will occur under specific exposure conditions.

What is the critical toxic effect?

The mos serious adverse affect which occurs at the lowest exposure level. Use in the calculation of ADI, RfD or MRL

What is Risk Management?

The process of weighing policy alternatives and selecting the most appropriate regulatory action based on the results of RISK ASSESSMENT and social, economic and political concerns.

What three things are use in determining risk of Non-carcinogens?

Threhold values NOAELs LOAELs Use of safety factors

What is the goal of risk assessment?

To determine the probability that an adverse effect will occur at a defined exposure level

What is the Linearized multi stage (LMS) model used for? Why?

Used for the risk assessment of Carninogens. Because carcinogens have no threshold.

What is risk characterization?

estimation of the incidence of health effects under the various conditions of human exposure

What is the equation of Chronic daily dose (CDI)?

( (mg/kg/day) x years) / 70 years

What makes human risk assessment complicated?

-Simultaneous exposure to difference substances with potential for numerous chemical and biological interactions. -Also different susceptibility (infants vs adults)

What two specific questions in vitro cell and biochemical studies used to answer?

1 -Identify the mechanism by which a substance has produced an effect in the animal bioassay 2 - To determine species diffences. (often pathways in animal are not present in human)

What is a Cancer slope factor?

A value that quantitatively defines the relationship between dose and response. The plausible upper bound estimate of the probability that an individual will develp cancer if eposed to a chemical for a lifetime of 70 years. mg/kg/day

What is acceptable Daily Intake (ADI)?

Amount of a chemical to which a person can be expose each day for a long time (lifetime) without suffering harmful effects.

What is the primary data used in risk assessments?

Animal Bioassays

What is the problem with risk communication?

Because the education level of the public is often low. Its difficult for scientist to get down to the level of understanding of the public. Often time there are miscommunication.

What is the equation for Risk (cancer)?

CDI (Chronic Daily Dose) X CSF (Cancer Slope Factor)

How is the daily allowable limit calculated?

CSF/70kg X 20 m3/day (air) or 2 L/day (water)

What is a hazard?

Capability of substance to cause and adverse affect

What is the equation for human equivalent dose (HED)?

HED = Animal dose (mg/kg) X (Animal Km / Human km)

What are the 4 steps in risk assessment

Hazard identification Dose-response assessment Exposure assessment Risk characterization

EPA Group A

Human Carginogen - sufficient evidence

What is the ADI equation?

NOAEL (experimental dose) / Safety Factor (s)

EPA Group D

Not classifiable as to human carcinogenicity - inadequate animal evidence

EPA Group B2

Probable Human Carcinogen - inadequate evidence in humans sufficient evidence in animals

What is SARs? (tox definition)

a chemical's toxicity base on its similarity in structure to that of chemical for which the toxicity is known.

What is hazard identification?

characterization of innate adverse toxic effects of agents

What is Dos-Response assessment?

characterization of the relation between dose and incidences of adverse effects in exposed populations

What is exposure assessment?

measurement or estimation of the intensity, frequency, and duration of human exposures to agents.

What is Risk assessment?

the PROCESS by which HAZARD, exposure and risk are determined

What is the major problem with epidemiology studies?

they are usually initiated long after the exposure to the xenobiotic. Usually have incomplete and unreliable exposure histories. difficult to construct reliable dose-response relationship