1.5 Humans & 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

1. Construct systems diagrams to show the impact of pollutants.

2. Evaluate the effectiveness of each of the three different levels of intervention, with reference to figure 3.

3. Evaluate the uses of DDT.

Guidance

• The terms “pollutant” and “contaminant” in environmental chemistry are considered more or less synonymous.

• Pollution which arises from numerous widely dispersed origins is described as non-point source. Point source pollution arises from a single clearly identifiable site.

• “Biodegradable” means capable of being broken down by natural biological processes

• The principles of this sub-topic, particularly Figure 3 (below), should be used throughout the course when addressing issues of pollution.

• Students should be aware that for some pollutants there may be a time lag before an appreciable effect on organisms is evident.

• With reference to Figure 3 (below), students should appreciate the advantages of employing the earlier strategies of pollution management over the later ones, and the importance of collaboration.

• Students might demonstrate knowledge of both the anti-malarial and agricultural use of DDT.

Textbook Reading and/or Activities

• Pages 78-80, 96-102, 160-165, 217-218, 223-230

Notes

i-Biology Notes (Not available)

A detailed set of notes, created by Stephen Taylor, examining UX - UY and AX - AY.

i-Biology Study Questions (Not available)

A series of questions, created by Stephen Taylor, to help check your understanding of the IB learning expectations. This is VERY GOOD practice.

Bioknowledgy Notes (Not available)

A detailed set of notes, created by Chris Paine, examining all of the IB learning expectations.

Bioknowledgy Study Questions (Not available)

A series of questions, created by Chris Paine, to help check your understanding of the IB learning expectations. This is VERY GOOD practice.

Learning Activities

Creating an Environmental Impact Assessment

This activity is designed to help you better understand the concept of an EIA and the process by which it is carried out.

Supplemental Reading

Resource

Description

Key Vocabulary

• Here