1. What are the steps involved in evaluation of toxicity?
a) hazard identification and dose-response evaluation
b) chemical analysis
c) pathway analysis
d) evaluation of long term impact
Explanation: Hazard identification includes a description of the specific forms of toxicity and Dose-response evaluation is incidence of specific toxins subjected to population
2. ___________ establishes the relationship between the contaminant/s of concern and the receptor.
a) Hazard identification
b) Toxicity assessment
c) Risk characterisation
d) Exposure assessment
Explanation: Toxicity assessment is the Characterization of the toxicological properties and effects of a chemical, with special emphasis on establishment of dose-response characteristics
3. Which of the following is not characteristics of hazardous waste?
a) Toxicity
b) Corrosivity
c) Ignitibility
d) Leakage
Explanation: Toxicity, corrosivity, ignitibility and reactivity are the aspects considered in quantification and characterisation of hazardous waste.
4. What is toxicity equivalence factor?
a) Ratio of the toxicity of a chemical to that of another structurally related chemical (or index compound) chosen as a reference
b) Ratio of the toxicity of a contaminant to that of another structurally related chemical (or index compound) chosen as a reference
c) Ratio of the toxicity of a chemical to that of another chemical pollutant chosen as a reference
d) Ratio of the toxicity of a chemical to that of source
Explanation: Factor used to estimate the toxicity of a complex mixture, commonly a mixture of chlorinated dibenzo-p-dioxins [oxanthrenes], furans, and biphenyls.
5. Results from long-term exposure to lower doses of a chemical is known as ________
a) Acute toxicity
b) Chronic toxicity
c) Moderate toxicity
d) High toxicity
Explanation: Chronic toxicity is the development of adverse effects as the result of long term exposure to a toxicant or other stressor.
6. Toxicity test is the experimental study of the adverse effects of exposure of a living organism to a substance for a defined duration under defined conditions.
a) true
b) false
Explanation: Toxicity testing is conducted to determine the degree to which a substance can damage a living or non-living organisms.
7. _________ is an interpretation tool which enables toxicity of unknown mixtures of chemicals be converted into the concentration of an equivalently toxic reference substance.
a) Toxicity equivalencing
b) Toxicity index
c) Toxicity proportion
d) Toxicity interpretation
Explanation: Toxicity equivalencing tool is used to evaluate the amount of toxicity and estimates the risks of a mixture of structurally related chemicals with a common and same mechanism.
8. Which toxicity test is preferable to determine the acute or chronic toxicity of air, water and wastewater discharges or total pollutant loads?
a) Indirect toxicity test
b) Direct toxicity test
c) Chemical analysis
d) High toxicity test
Explanation: The use of DTA allows an assessment of the toxicity of mixtures of chemicals rather than individual chemicals
9. What is the main objective of toxicity assessment?.
a) To determine source of pathway
b) To determine chemical concentration
c) To estimate how much of a substance does what kind of harm.
d) To analyse chemical exposure
Explanation: The main objective of toxicity assessment is the classification and grouping according to toxicological properties of a substance, specifically the dose-response relationship a with a specific route of exposure.
10. What is the third step of risk assessment?
a) Hazard identification
b) Toxicity assessment
c) Exposure assessment
d) Corrosivity assessment
Explanation: Risk assessments combine information on the level of exposure to substance and its toxicity to characterize what is likely to happen to humans who may be exposed.