1.5 Humans and pollution

Significant ideas:

  • Pollution is a highly diverse phenomenon of human disturbance in ecosystems.
  • Pollution management strategies can be applied at different levels.

Knowledge and understanding:

  1. Pollution is the addition of a substance or an agent to an environment through human activity, at a rate greater than that at which it can be rendered harmless by the environment, and which has an appreciable effect on the organisms in the environment.
  2. Pollutants may be in the form of organic or inorganic substances, light, sound or thermal energy, biological agents or invasive species, and may derive from a wide range of human activities including the combustion of fossil fuels.
  3. Pollution may be non-point or point source, persistent or biodegradable, acute or chronic.
  4. Pollutants may be primary (active on emission) or secondary (arising from primary pollutants undergoing physical or chemical change).
  5. Dichlorodiphenyltrichloroethane (DDT) exemplifies a conflict between the utility of a “pollutant” and its effect on the environment.

Applications and skills:

  • Construct systems diagrams to show the impact of pollutants.
  • Evaluate the effectiveness of each of the three different levels of intervention, with reference to figure 3.
  • Evaluate the uses of DDT.

International-mindedness:

  • Pollution cannot be contained by national boundaries and therefore can act either locally, regionally or globally.

Theory of knowledge:

  • Experts sometimes disagree about pollution management strategies – on what basis might we decide between the judgments of the experts if they disagree?

Connections:

  • Stratospheric ozone (6.2)
  • Photochemical smog (6.3)
  • Water pollution (4.4)
  • Terrestrial food production systems and food choices (5.2)
  • Human population carrying capacity (8.4)
  • Biodiversity and conservation (topic 3)