the effects of environmental features on severity of pollution

the breaking down of a substance

1) temperature 2) light levels 3) oxygen 4) PH 5) pollutant interactions

• higher temperatures increase the rate of breakdown - for example pollution such as sewage will break down more rapidly at high temps

• high temps increase the speed of breakdown- rapid degradation can increase problems such as deoxygenation of water bodies as it increases the rate of decomposition which is an aerobic process so oxygen is taken and and carbon dioxide released

• light can act as an activation energy which drives the chemical reactions involving pollutants • for example photochemical smogs and the photodegradation of some pesticides

• oxygen is involved in many chemical and biological reactions involving pollution • for example 1) aerobic bacteria breakdown of sewage 2) oxidation of sufides ores producing sulphur dioxide • the oxidation sate affects the solubility of many metals

the oxidation state affects the solubility of many metals- therefore allowing them to enter different pathways and become more mobile

• PH can affect the solubility of substances - many heavy metals such as lead become more soluble and therefore mobile under acidic conditions

• the behavior of one pollutant may be affected by the presence of another for example 1) interactions of nitrous oxides and hydrocarbons in photochemical smogs 2) the combined affect of phosphates and nitrates in eutrophication

• causes the formation of secondary more toxic pollutants such as PANs • UV light can split molecules such as nitrogen dioxide into monatomic oxygen in nitric oxide, the oxygen can then go on to form tropospheric ozone which goes to form a secondary pollutant PANS

by basic/alkaline rocks

1) wind and water currents 2) temperature inversions

1) atmospheric temps in the troposphere normally decline with altitude 2) warm pollutant gases released at ground level are less dense so rise 3) the rising of the pollutant causes it to disperse and become diluted 4) as the pollutants rise they cool, however, the surrounding air is also cooler so they continue to rise and disperse

velocity and direction of air and water will affect how far a pollutant travels but also how much it is diluted

• pollutants may absorb onto materials such as clay particles in aquatic sediments and become immobilised which stops it causing problems • other toxic metals may be absorbed such as lead or aluminium

1) valleys where cold dense air can collect 2) low wind velocity- so that air layers with different temps dont mix 3) cloudless skies- infrared radiation emittes from the ground faster causing increased cooling 4) mist or fog- water condenses at ground layer creating an albedo affect reflecting sunlight so the ground cools