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