Since humans first arrived in New Zealand, we have had a significant impact on the environment. How have we left our mark on our land, our air and our water?
This resource provides explanations of the key concepts encountered when exploring how we affect and protect the natural world around us - the ‘basics’ that every student should understand.
- Resource management
Human impact on the environment is managed in a way that is sustainable. This enables us to protect our natural resources so that we will be able to provide future generations with social, economic and cultural wellbeing. Any adverse effects of human impact need to be remedied and, if possible, the environment returned to its natural state.
When a compound becomes dissolved in water and moves from one place to another, for example, a fertiliser in the soil dissolves in rain water and ends up in a stream. The product of leaching is called a leachate. Any toxins in the soil, or toxins from landfill, will eventually leach into our waterways. This is a major contributor to pollution, as aquatic plants and animals are highly susceptible to toxins.
A living organism that is too small to see without a microscope, for example, bacteria, fungi, yeast, protozoa and viruses. Bacteria and viruses are common pathogens. Bacteria are single celled organisms. Viruses are extremely small particles that need to infect a cell to reproduce.
A microorganism capable of causing disease. Bacteria are responsible for human diseases such as conjunctivitis, wound infections and tuberculosis. Common colds and flu are both caused by viruses. Fungi can also cause diseases, for example, ringworm. Giardia is a protozoa, and dandruff is caused by yeast.
Fine particles of a liquid or a solid suspended in a gas, for example, the visible soot suspended in smoke. Particulates affect health by getting into the lungs and blocking air passages. Most particulates are created by burning, for example, by log burners or car engines.
A substance that causes harm to living organisms. These substances can be chemical, biological or physical. Toxicity is the level of harm a toxin can cause and is related to how potent the toxin is and how susceptible the organism is to that toxin.
A biological indicator of a chemical. Organisms can show a physiological or biochemical change in response to a chemical in its environment, for example, an earthworm can demonstrate a reduced nerve conduction velocity in response to certain toxins in the soil.
The ability of a substance to break down in the environment into harmless compounds. The substance is broken down by the action of microorganisms in the soil or water. The biodegradability of a substance relates to how quickly these organisms are able to break it down – generally the less ‘natural’ a substance is, the slower it will biodegrade.
The study of health of a population. Rather than looking at the health of an individual, epidemiology looks at the population as a whole. This is useful in looking at trends relating to pollution, for example, in areas of high particulates, or an outbreak of disease caused by poorly treated water.