Self-Assessment Questions (SAQs) for Study Session 8
Now that you have completed this study session, you can assess how well you have achieved its Learning Outcomes by answering the following questions.
SAQ 8.1 (tests Learning Outcome 8.1)
Define the words biodegradation, bioaccumulation and biomagnification, and explain the difference between them.
Answer
Degradation means ‘breaking down’, and biodegradation means the breaking down of complex substances into simpler substances by biological processes, mostly the action of bacteria. Accumulation means ‘build-up’, and bioaccumulation is the gradual build-up or increase of persistent pollutants in the body of individual animals as they eat contaminated food. Magnify means ‘to enlarge’ and biomagnification is the gradual increase of pollutants in the bodies of different organisms linked by a food chain.
So, all these processes involve living organisms (biological processes), but the first involves the breaking down of complex substances, the second involves build-up of persistent pollutants in an organism and the third involves the increase of pollutants up the food chain.
SAQ 8.2 (tests Learning Outcomes 8.1 and 8.2)
Nutrients such as nitrogen and phosphorus are useful to farmers who apply them to fields to help increase growth of their crops. Write a paragraph that explains how these same nutrients cause pollution when they are washed off into rivers and lakes. Your answer must include the following words: algal bloom; deoxygenation; eutrophic; fish; organic matter.
Answer
Your answer will not be exactly the same; this is one possible answer.
When nitrogen and phosphorus are washed into a river or lake, the water becomes eutrophic, meaning that it has high levels of plant nutrients. This will cause excess plant growth and may produce a sudden increase in microscopic algae called an algal bloom. When the plants die, the dead plant material adds to the organic matter in the water. Decomposition of the organic matter can result in deoxygenation of the water, which will kill fish.
SAQ 8.3 (tests Learning Outcome 8.3)
Give three examples of air pollutants, three examples of sources of air pollution and three possible effects of air pollution on human health.
Answer
You may have chosen any of the following:
Examples of air pollutants: dust, soot, particulates, nitrogen oxides, sulphur dioxide, carbon monoxide.
Sources: domestic fires, vehicle emissions, industrial chimneys.
Effects on human health: reduced lung function (difficulty with breathing), asthma, bronchitis.
SAQ 8.4 (tests Learning Outcomes 8.1 and 8.4)
- a.Complete all the gaps in the table below.
| Water pollutant | Exposure route | Human health effect |
| Vibrio cholerae bacteria | ||
| schistosomiasis/bilharzia | ||
| organic mercury | ingestion | |
| ascariasis |
- b.Which of the diseases in your completed table are transmitted by faecal-oral transmission?
Answer
- a.The answers are as follows:
| Water pollutant | Exposure route | Human health effect |
| Vibrio cholerae bacteria | ingestion | cholera |
| Schistosoma worm | skin contact | schistosomiasis/bilharzia |
| organic mercury | ingestion | Minamata disease |
| Ascaris worm | ingestion | ascariasis |
- b.Cholera and ascariasis are both transmitted by the faecal-oral route. People become infected with these diseases when they drink water or eat food that is contaminated with faecal matter from infected individuals.
SAQ 8.5 (tests Learning Outcomes 8.1 and 8.5)
A junior manager in a manufacturing company is asked to write a report to the Chief Executive with recommendations for reducing the environmental impact of their factory. Rewrite this extract from the report using terms from the list provided to fill the gaps:
cleaner production; pollution prevention; precautionary principle; polluter pays principle; recycling; reduce; reuse; waste hierarchy; waste minimisation.
Our company has a duty to reduce pollution from the wastes produced in our factory. We should adopt policies of ………………, which avoid pollution in the first place. I recommend that we follow the ……………… and do not assume that our wastes will not cause any environmental damage. We should adopt ……………… processes to ensure we reduce our impact on the environment.
For management of the solid wastes produced in our factory we should follow the ……………… This means we should first ……………… the amount of waste produced and identify opportunities for ……………… and ……………… If we successfully adopt these ……………… procedures we will reduce potential pollution from our company. Although some costs may be incurred, this could save money in the long run because under the ……………… we may be liable for costs of any environmental damage that we cause.
Answer
Our company has a duty to reduce pollution from the wastes produced in our factory. We should adopt policies of pollution prevention, which avoid pollution in the first place. I recommend that we follow the precautionary principle and do not assume that our wastes will not cause any environmental damage. We should adopt cleaner production processes to ensure we reduce our impact on the environment.
For management of the solid wastes produced in our factory we should follow the waste hierarchy. This means we should first reduce the amount of waste produced and identify opportunities for reuse and recycling. If we successfully adopt these waste minimisation procedures we will reduce potential pollution from our company. Although some costs may be incurred, this could save money in the long run because under the polluter pays principle we may be liable for costs of any environmental damage that we cause.
Summary of Study Session 8