Env. Health Chap 3

Target Organ Effect

Some chemicals may confine their effects to specific organs; the most common organs affected are the liver, lungs, heart, kidneys, brain, nervous system and reproductive system

The 4 steps of risk assessment

1) Hazard Identification 2) Dose-response assessment 3) Exposure assessment 4) Risk characterization

Carcinogen

A chemical or substance that causes or is suspected of causing cancer

External Dose

A dose acquired by contact with contaminated environmental sources

Toxic Agent

A material or factor that can be harmful to biological systems

Toxic Substance

A material that has toxic properties

Risk Assessment

A process for identifying adverse consequences and their associated probability

Hazard Identification

Examines the evidence that associates exposure to an agent with its toxicity and produces a qualitative judgment about the strength of that evidence, wether it is derived from human epidemiology or extrapolated from laboratory animal data

1. An example of in vitro testing for toxicology is: A. Experiments with normal volunteers B. Experiments with volunteers who have had unintentional exposures C. Studies of animals exposed to toxins D. Dose-response assessments in human populations E. Experiments with cells derived from human sources

Experiments with cells derived from human sources (correct)

Chronic

Exposure for more than three months

Subacute

Exposure for one moth or less

Subchronic

Exposure for one to three months

3. Chose the incorrect statement below. Thalidomide is an example of a drug that A. Was a potent teratogen B. Was developed before the advent of rigorous clinical trials C. Was used to treat morning sickness during pregnancy D. Was associated with heart problems among adults E. None of the above

Was associated with heart problems among adults(correct)

7. Hazard identification refers to the question of A. What are the health effects that this agent can cause? B. What is the relationship between dose and occurrence of health effects in humans? C. What exposures are currently experienced or anticipated under different conditions? D. What is the estimated occurrence of the adverse effect in a given population? E. None of the above.

What are the health effects that this agent can cause? (correct)

6. Exposure assessment refers to the question A. What are the health effects that this agent can cause? B. What is the relationship between dose and occurrence of health effects in humans? C. What exposures are currently experienced or anticipated under different conditions? D. What is the estimated occurrence of the adverse effect in a given population? E. None of the above.

What exposures are currently experienced or anticipated under different conditions? (correct)

Toxin

A toxic substance made by living organisms including reptiles, insects, plants and microorganisms

18. What type of combination of two chemicals produces an effect that is equal to their individual effects taken together A. Additive B. Synergistic C. Potentiative D. Coalitive E. Antagonistic

Additive

Systemic effects

Adverse effects associated with generalized distribution of the chemical throughout the body by the bloodstream to internal organs

13. Specific examples of xenobiotics are A. Antibiotics B. Therapeutic drugs C. Dioxins D. PCBs E. All of the above

All of the above(*)

15. The concentration and toxicity of a chemical in the body are affected by A. Route of entry into the body B. Received dose of the chemical C. Duration of exposure D. Individual sensitivity E. All of the above

All of the above(*)

16. The existence of a dose-response relationship may be used to establish the following kinds of information A. Causal association between a toxin and biological effects B. Minimum dosages needed to produce a biological effect C. Rate of accumulation of harmful effects D. All of the above E. A & B only

All of the above(*)

Chemical Allergy

An immunologically mediated adverse reaction to a chemical resulting from previous sensitization to that chemical or to a structurally similar one

Posion

Any agent capable of producing a deleterious response in a biological system

8. In comparison with the general population, workers may receive exposures to toxic chemicals that are A. At lower levels for shorter time periods B. At higher concentrations for much longer time periods C. Confined to a single time episode D. More likely to be associated with acute effects than long-term effects E. None of the above

At higher concentrations for much longer time periods (correct)

Where do hazards originate from?

Chemicals Biological agents Physical/mechanical energy and force Psychosocial Influences

Xenobiotics

Chemicals that can produce developmental toxicity

19. What type of interaction among several agents that have no known toxic effects produces a toxic effect? A. Additive B. Synergistic C. Potentiative D. Coalitive E. Antagonistic

Coalitive

Local effects

Damage at the site where a chemical first comes into contact with the body; examples are redness, burning and irritation of the skin

Spectrum of Toxic Dose

Describes the toxicity or hazards that are related to exposure to a particular chemical

Unknown Risk

Hazards judged to be unobservable, unknown, new and delayed in their manifestation

Synergism

Indicates that the combined effect of exposures to two or more chemicals is greater than the sum of their individual effects

Hazard

Inherent capability of an agent or a situation to have an adverse health effect

4. Direct adverse effects of xenobiotics do not include A. Cell replacement B. Interference with nutrition C. Damage to an enzyme system D. Disruption of protein synthesis E. DNA damage

Interference with nutrition (correct)

9. Of the following routes of exposure, which one has the most rapid effect? A. Intravenous B. Ingestion C. Dermal D. Intramuscular E. Inhalation

Intravenous

21. Which of the following abbreviations is used to describe toxic effects of chemicals? A. VOCs B. TLV C. TFR D. AQI E. LD50

LD50

12. Risk management refers to the question of A. What are the health effects that this agent can cause? B. What is the relationship between dose and occurrence of health effects in humans? C. What exposures are currently experienced or anticipated under different conditions? D. What is the estimated occurrence of the adverse effect in a given population? E. None of the above.

None of the above.(*)

14. Subacute exposures are those that last A. Less than 24 hours and occur once B. Less than 24 hours and occur more than once C. One month or less D. One to three months E. More than three months

One month or less(*)

10. One of the founders of toxicology was A. Socrates B. Theophrastus C. Claudius D. Da Vinci E. Paracelsus

Paracelsus(*)

Dread Risk

Perceived lack of control, dread, catastrophic potential, fatal consequences and the inequitable distribution of risks and benefits

20. What type of interaction between two chemicals causes one chemical that is not toxic to become more toxic A. Additive B. Synergistic C. Potentiative D. Coalitive E. Antagonistic

Potentiative

Exposure

Proximity and/or contact with a source of a disease agent in such a manner that effective transmission of the agent or harmful effects of the agent may occur

Coalitive Interaction

Several agents that have no know toxic effects interact to produce a toxic effect

22. Which of the following is not likely to characterize the approach of toxicology A. Laboratory studies of the role of xenobiotics in carcinogenesis in mice B. Studies of disease occurrence in populations according to person variables C. In vitro studies D. In vivo studies E. They all characterize the toxicologic approach.

Studies of disease occurrence in populations according to person variables

Dose

The amount of substance administered at one time

Exposure Dose

The amount of substance encountered in the environment

Absorbed Dose

The amount of substance that is available to the internal organs of the body

Reproductive toxicology

The association between chemical and adverse effects upon the reproductive system

Additive

The combination of two chemicals produces a effect that is equal to their individual effects added together

Toxicity

The degree to which something is poisonous

Developmental toxicology

The effects of natural and man-made chemicals on prenatal development

Threshold

The lowest dose at which a particular response many occur

Dose-Response Assessment

The measurement of the relationship between the amount of exposure and the occurrence of the unwanted health effects

2. An internal dose refers to A. The dose acquired by contact with contaminated environmental sources B. The amount of a substance that is available to the internal organs of the body C. The portion of a substance that becomes internalized in the body D. The quantity of a substance that is administered E. None of the above

The portion of a substance that becomes internalized in the body (correct)

Internal Dose

The portion of a substance that becomes internalized in the body through ingestion, absorption and other means

Biologically Effective Dose

The portion of the internal dose that is required to cause a health outcome

Exposure Assessment

The procedure that identifies populations exposed to the toxicant , describes their composition and size, and examines the roots, magnitudes, frequencies and durations of such exposures

Administered Dose

The quantity of a substance that is administered

Toxicology

The study of adverse effects of chemicals on living organisms

Environmental Toxicology

The study of how ecological systems (their structure, dynamics, function, etc) are affected by pollutants

17. The poisonous substance in Amanita phalloides ("death cap" mushroom) is an example of a: A. Toxicant B. Toxin C. Anthropogenic form of poison D. A poison caused by bacterial activity E. None of the above

Toxin

Antagonism

Two chemicals administered together interfere with each others actions or one interferes with the action of the other

Acute

Usually a single exposure for less than 24 hours

11. Risk characterization refers to the question of A. What are the health effects that this agent can cause? B. What is the relationship between dose and occurrence of health effects in humans? C. What exposures are currently experienced or anticipated under different conditions? D. What is the estimated occurrence of the adverse effect in a given population? E. None of the above.

What is the estimated occurrence of the adverse effect in a given population? (*)

5. Dose-response assessment refers to the question of A. What are the health effects that this agent can cause? B. What is the relationship between dose and occurrence of health effects in humans (or animals)? C. What exposures are currently experienced or anticipated under different conditions? D. What is the estimated occurrence of the adverse effect in a given population? E. None of the above.

What is the relationship between dose and occurrence of health effects in humans (or animals)? (correct)

Potentiation

When one chemical that is not toxic that causes another chemical to become more toxic