pollution indicators- eitp

8/12/2019 Pollution Indicators- EITP

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Human beings compete with other living things for resources and space. As theworld’s population continues to increase, and standards of living improve, thereis serious danger of a permanent change to the global environment.

Human activities have led to the pollution of the environment, particularly inwater and the air. Eutrophication is one example of this.

Global population change

Population growthLike all living things, humans exploit their surroundings for resources. Before thebeginning of agriculture about 10,000 years ago, small groups of humans wanderedacross large areas, hunting and gathering just enough food to stay alive. opulationnumbers were kept low because of the difficulty of finding food.

!he development of agriculture led to a population explosion that has acceleratedenormously during the past "00 years. #nlike other species, humans can adapt to and

survive in almost all habitats and climates.

$uman population growth over the past 10,000 years

tandards of living

eople in the developed world enjoy a high standard of living, with abundant food,cars and comfortable housing. eople in the developing world have a lower standardof living, but many countries are catching up %uickly.

!mpact of humans!he world&s human population has passed ' billion and continues to increase. !hegrowth in the human population and the increase in the standard of living are puttingstrains on the global environment. $ere are some of the ways in which this ishappening(

• non)renewable energy resources, such as coal, oil and natural gas, are beingused up rapidly

• raw materials are being used up rapidly• more waste is being produced



• more pollution is being caused

Air pollution

*actories can cause air pollution!he most common source of air pollution is the combustion of fossil fuels . !hisusually happens in vehicle engines and power stations.

ome common air pollutants and their effect

pollutant typical effect

smoke deposits soot on buildings and trees, causing them damage. ermeatesthe air, making it difficult for living creatures to breathe.

carbon

monoxide

poisonous gas

carbondioxide

greenhouse gas that contributes to global warming

sulfur dioxide contributes to acid rain

!ndicators of air pollutionLichens are plants that grow in exposed places such as rocks or tree bark. !hey needto be very good at absorbing water and nutrients to grow there, and rainwater contains

just enough nutrients to keep them alive. +ir pollutants dissolved in rainwater,especially sulfur dioxide, can damage lichens, and prevent them from growing. !hismakes lichens natural indicators of air pollution. *or example(

• bushy lichens need really clean air• leafy lichens can survive a small amount of air pollution• crusty lichens can survive in more polluted air.

n places where no lichens are growing, it-s often a sign that the air is heavily pollutedwith sulfur dioxide.

+nother indicator of air %uality is the blac"spot fungus on roses. Blackspot fungusgrows well on roses in unpolluted areas because it is killed by the presence of sulfurdioxide that would be found in polluted air.

#ater pollution



#ater pollutantsncreasing human population has led to an increase in pollution. ome of this is dueto(

• more fossil fuels being burnt for heat and power•

more food being grown• land taken over for industry and housing.

+s a result there has been an increase in levels of water pollution.• /itrate fertilisers are very soluble in water and are easily washed off fields by

the rain and then into rivers and reservoirs. Because nitrates are all soluble theycannot easily be removed from the water.

• esticides used by farmers to kill weeds or insects may be washed or blowninto streams and rivers.

• ulfur dioxide in the air can dissolve in water to form an acidic solution.

Pollution indicators!he level of pollution in water can be indicated by the species living there. !his isknown as an indicator species .

pecies that indicate pollution levels

pollution level of water species

polluted bloodworm

polluted sludgeworm



Eutrophication

+ major problem with the use of fertilisers occurs when they-re washed off the landby rainwater into rivers and lakes. !he resulting increase of nitrate or phosphate in thewater encourages algae growth, which forms a bloom over the water surface. !his

prevents sunlight reaching other water plants, which then die. $acteria break downthe dead plants and use up the oxygen in the water so the lake may be left completelylifeless.

!he increase of nitrate or phospate from fertilisers into water causes eutrophication

pollution indicators- eitp

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