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Air Pollution & Air Quality Monitoring Chapter 1

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Air Pollution & Air Quality Monitoring. Chapter 1. Assessment. Written Tests (2) 50 Practical Reports (min 5)40 Assignment10 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. - PowerPoint PPT Presentation

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Page 1: Air Pollution & Air Quality Monitoring

Air Pollution & Air Quality Monitoring

Chapter 1

Page 2: Air Pollution & Air Quality Monitoring

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).

Page 3: Air Pollution & Air Quality Monitoring

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).

Page 4: Air Pollution & Air Quality Monitoring

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?

Page 5: Air Pollution & Air Quality Monitoring

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.

Page 6: Air Pollution & Air Quality Monitoring

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

Page 7: Air Pollution & Air Quality Monitoring

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.

Page 8: Air Pollution & Air Quality Monitoring

Introduction

Global Emissions form Natural & Man Made Sources

0

20

40

60

80

100

120

SOx CO NOx NH3 H/C Dust

Pollutant

% Emissions from NaturalSources

% Emissions from man madesources

Page 9: Air Pollution & Air Quality Monitoring

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

Page 10: Air Pollution & Air Quality Monitoring

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

Page 11: Air Pollution & Air Quality Monitoring

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.

Page 12: Air Pollution & Air Quality Monitoring

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”.

Page 13: Air Pollution & Air Quality Monitoring

Introduction

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

Page 14: Air Pollution & Air Quality Monitoring

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.

Page 15: Air Pollution & Air Quality Monitoring

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.

Page 16: Air Pollution & Air Quality Monitoring

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

Page 17: Air Pollution & Air Quality Monitoring

Element % (by volume) in the atmosphere

Total Mass in the Atmosphere (x1012

tonnes)

nitrogen 78.08 3900

oxygen 20.95 1200

argon 0.934 67

carbon dioxide 0.035 2.5

Neon 0.0018 0.065

Helium 0.00052 0.004

Methane 0.00015 0.005

Krypton 0.0001 0.017

Carbon Monoxide 0.00001 0.0006

Ozone 0.000002 0.0003

Nitrogen Dioxide 0.0000001 0.000013

Sulfur Dioxide 0.0000001 0.000018

water 0.1 – 5 (normal range 1-3) Varies according to location

Page 18: Air Pollution & Air Quality Monitoring

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).

Page 19: Air Pollution & Air Quality Monitoring

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.

Page 20: Air Pollution & Air Quality Monitoring

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.

Page 21: Air Pollution & Air Quality Monitoring

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

Page 22: Air Pollution & Air Quality Monitoring

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!

Page 23: Air Pollution & Air Quality Monitoring

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.

Page 24: Air Pollution & Air Quality Monitoring

The Atmosphere

Page 25: Air Pollution & Air Quality Monitoring

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.

Page 26: Air Pollution & Air Quality Monitoring

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.

Page 27: Air Pollution & Air Quality Monitoring

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.

Page 28: Air Pollution & Air Quality Monitoring

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

Page 29: Air Pollution & Air Quality Monitoring

Factors that make things worse

• calm conditions

• low level emission sources

• temperature inversions

• high buildings and narrow streets

Page 30: Air Pollution & Air Quality Monitoring

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