Air Pollution & Air Quality Monitoring

1. Air Pollution & Air Quality Monitoring Chapter 1

2. Assessment • Written Tests (2) 50 • Practical Reports (min 5) 40 • Assignment 10 • In order to pass this subject you will be required to obtain a minimum of 60% for both tests and hand in 5 practical reports. • Assessment will be competency based with grades of A, B, C, and NC (not competent).

3. Introduction • functions of the atmosphere include: • protection from harmful radiation • moderating the surface temperature • providing a medium (air) that allows organisms to exchange gases in order to survive (breathing).

4. Introduction • Any substantial change in the nature or contents of the atmosphere has a direct consequence on how well the atmosphere performs these tasks • Are there any current scenarios that this relates to?

5. Introduction • Historically air pollutants of greatest concern have been TSP, and oxides of sulfur, • More sophisticated processing industries = longer list of significant pollutants NOx and photochemical oxidants as routine pollutants, and often include Pb, asbestos, Hg, H2SO4 and many others that require careful monitoring.

6. Introduction • Non-pollutants e.g. CO2 also a problem • Wastes released into the atmosphere are diluted and dispersed in the air, and are processed and recycled through a variety of natural physical, chemical and biological mechanisms. • the atmosphere is continually cleaned of pollutants

7. Introduction • Atmospheric problems are made worse by weather conditions • The residence time determines significance of pollution problem • compared to natural sources, man’s activities produce a much smaller amount of global pollution.

8. Introduction

9. Introduction • Dispersal of pollutants is a very important consideration – as the atmosphere is not homogeneous - pollutants tend to concentrate in specific areas – most of which are near where large human populations reside • means that pollutant levels around residential areas are often much greater than would be expected in ambient air

10. Introduction • Natural sources are in general more evenly spread, but there are exceptions such as extremely high levels of dust and acidic gases associated with volcanic activity. • Man's activities (anthropogenic) release heat, gases, aerosols and other wastes into the atmosphere in high conc's overloading the natural dispersal, dilution and recycling systems

11. Introduction • Very little is known about the dispersal processes and the passage through ecological systems of pollutants. Many are resistant to degradation, some are cumulative and harmful.

12. Introduction • Air pollution definition • WHO • “Air is polluted when one or several pollutants are present in the atmosphere at such a conc. and for so long a time that they are harmful to man, animals, plants or material property, cause harm or reduce well-being or disturb appreciably its application”.

13. Introduction • NSW Protection of the Environment Operations Act as “any deviation from the natural combination of gases in our atmosphere”.

14. Introduction • Definition fails to mention is that the natural combination of gases in our atmosphere must be taken as dry air at sea level. • Neither completely cover other factors that we might also call pollution such as the release of energy, radiation, odour or noise.

15. Introduction • Most air pollution concerns are associated with ambient air (outdoors and free flowing) – hence most control programs focus on ambient air pollution, • significant pollution now occurs in occupational environments which are indoors.

16. The Atmosphere • Earth’s atmosphere 160 kilometers deep, 95% of air mass lies within 20 kilometers of the surface. • atmosphere is neither uniform, nor static in nature. Its characteristics vary widely with altitude, season, location and solar flare activity. • Air within a few kilometers of the earth’s surface will typically contain the components

18. The Atmosphere • The pollutants with which we have the most problems make up an extremely small part of the atmosphere. • In polluted city areas these % conc's will change markedly for some pollutants. • The conc's of N, O, Ar, Ne, He, Kr, H and Xe remain essentially constant (most are inert and play little or no role in atmospheric chemistry).

19. The Atmosphere • N is a precursor for other species such as NO3-, as well as amino acids and nucleic acids (amongst others) which are essential for life, and reacts with O. • O2 important for the nurturing of life, and forming ozone (O3), acts as a heat and radiation shield for the planet – maintaining fairly constant temperatures that allow life to exist.

20. The Atmosphere • At 0.035%, CO2 in the atmosphere is very low - enormous significance as the raw material used by plants for carbon fixation to produce the compounds used for energy by almost all forms of life. • also a significant greenhouse gas – which serves to keep the planet warm. • Water vapour is the most variable (from 0.1 – 30,000ppm). • allows the transport of energy around the planet.

21. The Atmosphere • Forms clouds that are responsible for the Earth’s albedo – the ability of the Earth to radiate sunlight back into space –controlling the Earth’s surface temperature • trace gases produced from biological or geological processes, NH4, CH4, H2S, CO and SO2

22. The Atmosphere • The avg. person breathes 20,000L of air per day • 995 of which is N or O. • 1% is a mixture of gases and particulates, many of which are pollutants. • we breathe as much as 200L of pollutants per day!

23. Stratification of the Atmosphere • stratification – or layering of the atmosphere • 95% of the atmosphere’s air mass is found in the troposphere. The upper troposphere has a temperature of -56ºC. • At the top of the troposphere is the tropopause layer - a barrier to prevent water vapour rising much higher as it causes ice formation. • Water vapour cannot pass through it. • stratosphere, - The ozone layer is within the stratosphere, and reaches levels of up to 10ppm in the middle of the stratosphere – gets hotter due to this.

24. The Atmosphere

25. The history of air pollution • Air pollution was probably as much a problem to cave men as it is today. • Reports of air pollution and decimation of forests have been recorded since the 14th C. • mostly linked with the burning of soft coal with a high sulfur content. This activity produces smoke, sulfur dioxide and particulate matter containing HCs.

26. The history of air pollution • London "pea souper" fogs. • type of smog is grey in colour and is generally referred to as London type smog. • Meuse Valley of Belgium 60 deaths. 21 people were killed in Donora, Pennsylvania, • Most victims died of lung and breathing disorders. Of the survivors, 7000 of the total population of 14000 became seriously ill.

27. The history of air pollution • Los Angeles type smogs conditions different to those in London • Large amounts of NO2 and unburnt HC’s, which then react in the atmosphere in the presence of UV light and oxidants to form a brown photochemical smog.

28. Haze or smog? • Haze, but how is it different to smog? • Both typified by a reduction in visibility, but the intensity varies. • Haze is a condition where the reduction in visibility is not great, and is generally applied to describe the atmospheric conditions over a very large area • Smog is significant reductions in visibility, generally in metropolitan areas

29. Factors that make things worse • calm conditions • low level emission sources • temperature inversions • high buildings and narrow streets

30. The POEO Act • This act specifies all legal requirements for the control of air pollution in NSW. • The current regulation pertaining to air pollution control (in NSW) is called the; Protection of the Environment Operations (Clean Air) Regulation 2002