23/05/2018 Air Quality (OCR) W Richards The Weald School

The Earth’s Atmosphere 23/05/2018 Present day atmosphere contains 78% nitrogen, 21% oxygen, 1% noble gases and about 0.03% CO2 Carbon dioxide, water vapour Oxygen Nitrogen Noble gases

Pollution Humans pollute the Earth in a number of ways: Pollutant 23/05/2018 Humans pollute the Earth in a number of ways: Pollutant Harmful to... Why? Carbon dioxide Environment Nitrogen oxides Environment + humans Sulfur dioxide Particulates (e.g. Smoke) Carbon momoxide Humans A greenhouse gas that causes global warming Causes acid rain and makes asthma/breathing problems worse Causes acid rain Makes buildings dirty and makes asthma worse Displaces oxygen in red blood cells that can result in death

Measuring pollution Low concentration High concentration 23/05/2018 Low concentration High concentration Concentration is measured in Parts per Million (ppm) or Parts per Billion (ppb).

Carbon monoxide concentration (ppm) Some sample data 23/05/2018 Location Time Carbon monoxide concentration (ppm) London 9am 11am 1pm 3pm 5pm 6.4 6.2 5.9 3.1 6.3 The Cotswolds 0.2 0.1

These atoms are ALL iron – there’s nothing else in here Elements 23/05/2018 If a solid, liquid or gas is made up of only one type of atom we say it is an element. For example, consider a tripod made up of iron: These atoms are ALL iron – there’s nothing else in here

Sodium chloride (salt) Compounds 23/05/2018 Compounds are different to elements. They contain different atoms. Here are some examples: Sodium chloride (salt) Methane Glucose

Some simple compounds… 23/05/2018 Methane, CH4 Carbon dioxide, CO2 Water, H2O Key Hydrogen Oxygen Carbon Sulphur Sulphuric acid, H2SO4 Ethyne, C2H2

Simple chemical reactions 23/05/2018 Mg O H Cl Magnesium oxide + Hydrochloric acid Magnesium chloride + Water MgO + 2HCl MgCl2 + H2O Mg O Cu S Magnesium + Copper sulphate Copper + Magnesium sulphate Mg + CuSO4 Cu + MgSO4

Burning Fuels – “Combustion” 23/05/2018 C H O O H C O Lots of oxygen: Methane Oxygen + Carbon dioxide Water + Water + O H Methane C H Oxygen + O C O Some oxygen: Carbon monoxide O H Water + C H Methane Little oxygen: O Oxygen + C Carbon

Other products of burning fuels 23/05/2018 S O Sulphur dioxide Sulphur dioxide: S O Sulphur Oxygen + Nitrogen monoxide N O Oxygen + O Nitrogen N Nitrogen monoxide: O Oxygen + Nitrogen monoxide N Nitrogen dioxide N O Nitrogen dioxide:

Pollution What happens to pollution? 23/05/2018 What happens to pollution? Carbon dioxide causes global warming but some of it can be removed by plants (photosynthesis) or reactions with seawater. Sulfur dioxide and nitrogen dioxide cause acid rain which damages trees and buildings. Particulates (like in smog) can make buildings dirty and worsen breathing difficulties.

Removing Pollution There are many ways pollution can be reduced: 23/05/2018 There are many ways pollution can be reduced: Use less electricity/central heating Remove toxic chemicals before or after they are burnt Use alternative energy sources, e.g. wind power

Reducing Pollution from vehicles 23/05/2018 A number of suggestions: 1) Buy a new, smaller, cleaner car 2) Buy a “hybrid” car 3) Convert your car to run on biodiesel 4) Make sure your car has a catalytic converter: Carbon monoxide + oxygen carbon dioxide Nitrogen monoxide + carbon monoxide nitrogen + carbon monoxide 5) Use the train or a bus!

Making choices about pollution 23/05/2018 Choices concerning fighting pollution can be made on many levels: International e.g. The Kyoto protocol in 1997 National e.g. Car tax system, subsidies for greener technology Local e.g. Recycling schemes, transport, congestion charges Personal e.g. Recycling, individual travel, reducing energy usage in the home etc