The effects of humans on the environment

Pollution (definition)

The addition of harmful substances to the environment

Examples of domestic waste

Paper, plastic, food waste

Examples of agricultural waste

Overuse of pesticides, fertilisers, slurry

Examples of industrial wastes

Oil, sulfuric dioxide

What can pollutants affect?

The air, the sea, the land, rivers/lakes

What is the problem with pesticides?

Herbivores eat producer with pesticide molecule, carnivore eats multiple herbivores and contains more pesticide molecules than the herbivore

Conservation (definition)

The wise management of the environment

Why is the conservation of organisms important?

Prevent extinction. Organisms may be found to produce new medicine. Maintain biodiversity + habitats

Agricultural conservation practices

Crop rotation. Controlled use of fertilizers

Fisheries conservation practices

Fishing quotas for different species. Diamond mesh net close under tension, trapping young fish. Square nets don’t do this, allowing baby fish to pass through and breed

How to store slurry correctly

In leak- proof pits

Should slurry be spread on dry land or wet land? Why?

Dry land to prevent it from entering waterways

What happens if slurry enters a lake?

Eutrophication

Explain eutrophication

Slurry contains nitrogen which causes algae to grow rapidly. When the algae die they’re broken down by bacteria which results in the absorption of oxygen from the water due to the bacteria respiring. Causes water to become deoxygenated, killing aquatic wildlife

Waste management (definition)

The way we as a society deal with our waste

Problems of waste disposal (3)

There may not be sufficient landfill sites available. Waste may be toxic. Liquid wastes can contaminate water supplies

What are the three R’s?

Reduce Reuse Recycle

Role of microbes in landfill sites

Break down wastes in landfill sites and garden compost bins

Role of bacteria in sewage

Break down sludge in sewage treatment plants

Role of bacteria in treating pollution

Feeds on oil and used to treat oil spills at sea

Role of bacteria in treating the soil

Absorbs heavy metals like zinc which may contaminate soils

Name an industrial pollutant

Sulfur dioxide

Source of sulfur dioxide

Burning of sulfur-containing fossil fuels

Effect of sulfur dioxide

Contributes to acid rain

Effects of acid rain

Corrodes limestone buildings. Makes soil acidic. Damages chlorophyll on leaves

What is ozone and what does it do?

A gas that forms a protective layer in the upper atmosphere. Absorbs and shields the earth from UV radiation

What chemical pollutants affect the ozone layer?

CFC’s. Industrial detergents.

What does CFC stand for?

Chlorofluorocarbons

Effects of ozone depletion (2)

Damage to crops. Increased number of skin cancers and cataracts

Name two ways to decrease ozone depletion

Reduce uses of CFC’s they’re replaced by HFC’s. Don’t dump fridges in landfills, return them to organisations that will dispose of them in an environmentally friendly way.

What does HFC stand for?

Hydrofluorocarbons