The following statements are True or False – Discuss.
- Sediments are a source of mercury.
- Wetlands are sinks for both sulphur and mercury.
- Natural activities (volcanoes, bushfires) can be sources of pollutants.
- Sinks can become more alkaline due to nitrates and SO2 entering the environment.
- Diffuse sources can be pin-pointed on a map.
- A chimney or pipe is a point source of emissions.
- Mobile pollutants are only released from vehicles on roads and freeways.
- Fugitive emissions are always gaseous.
- Mobile emissions are more easily controlled than fugitive emissions.
- Air (wind) and water currents are the only ways that pollutants can move.
- Light, gaseous pollutants are more mobile than heavy metal pollutants.
- Sulfur dioxide is more persistent than mercury.
- Mercury is more likely to bioaccumulate.
- Sulfur dioxide is water-soluble to form H2SO4.
- Only SO2 is released from combustion of fossil fuels.
- Both pollutants can act synergistically.
- Methyl-mercury is both water and fat soluble.
- SO2 disperses easily.
Question: “Identify the source of mercury from the lamp globes at landfill sites as either point or diffuse and give a reason for your identification.” (2 marks)
Examiner’s report: “Students were able to identify the lamp globes as being either a point source (if they identified a landfill site as a single, identifiable, localised source of mercury pollution) or a diffuse source (if they explained that more than one landfill site spread the source of pollution, or if they discussed many individual lamp globes spread throughout a large landfill site). Many students also wanted to include a ‘mobile’ source in their answer; however, this was not required, and was not relevant to the question.”