Presentation on theme: "Unit 5: Pollution Management IB Environmental Systems and Societies SL."— Presentation transcript:
Unit 5: Pollution Management IB Environmental Systems and Societies SL
5.1 Nature of Pollution Define the term pollution Distinguish between the terms point source pollution and non-point source pollution, and outline the challenges they present for management.
Define the term pollution. “Pollution has been defined as ‘the adverse effect on the natural environment, including human, animal or plant life, or a harmful substance that does not occur naturally, e.g. Industrial and radioactive waste, or the concentration to harmful levels of a naturally occurring substance, e.g. Nitrate’.” Robinson M.,(1996), Chambers 21 st century dictionary in Jarvis P.J., (2000), Ecological Principles and Environmental Issues, p. 74, Prentice Hall, London.
Distinguish between the terms point source pollution and non-point source pollution, and outline the challenges they present for management. Point Source Pollution – “...refers to discrete sources of contaminants that can be represented by single points on a map and the source of the pollution can be tracked.” Andrew Davis and Garrett Nagel, Environmental Systems and Societies, p. 217, Harlow: Pearson Education Ltd, 2010 Non-Point Source Pollution – “...refers to more dispersed sources from which pollutants originate and enter the natural environment.” Davis and Garrett Nagel, Environmental Systems and Societies, p. 218, Harlow: Pearson Education Ltd, 2010
State the major sources of pollutants. Construct a Pie chart using the following information. SourcePercentage Demolition and Construction8 Sewage Sludge8 Mining and quarrying27 Agriculture organic wastes from intensively farmed livestock 20 Industry17 Dredging sand and mud11 Domestic and Commercial9
5.2 Detection and Monitoring of Pollution Describe two direct methods of monitoring pollution. Students should describe one method for air and one for soil or water Define the term biochemical oxygen demand (BOD) and explain how this indirect method is used to assess pollution levels in water Describe and explain an indirect method of measuring pollution levels using a biotic index. This will involve levels of tolerance, diversity and abundance of organisms. The concept of indicator species should be understood. A polluted and an unpolluted site (for example, upstream and downstream of a point source) should be compared.
Describe two direct methods of monitoring pollution. Students should describe one method for air and one for soil or water. Air – Monitoring many pollutants such as Sulfur dioxide, oxides of nitrogen, ozone and volatile organic compounds. – Particulate matter Soil – pH levels Water – Biochemical Oxygen Demand (BOD) – Turbidity – Chemical Oxygen Demand (COD) – Ammonia – Dissolved Oxygen (DO)
Measuring Particulate Matter This is the amount of particles that we can collect and analyse. To do this; – Use petroleum jelly in the base of a petri dish. – Place petri in different locations – Look at the particulate matter under a hand lens or microscope. – Identify particulate matter as pollutants or non- pollutants.
Measuring Soil Characteristics pH levels Determine the levels of Ph, K, Ca. Identify any contaminants such as higher levels of Mg, Pb for example.
Turbidity Used to determine the amount of bacteria, silt and mud or chemicals the water contains. Many methods can be used; – Secchi Disk – Turbidity meter – Turbidity tube
Define the term biochemical oxygen demand (BOD) and explain how this indirect method is used to assess pollution levels in water. Biochemical Oxygen Demand is determined by: – The number of aerobic organisms in a river at any given point. – Their rate of respiration.
Measuring the BOD 1.Take a sample of water of a measured volume. 2.Measure the oxygen levels (using a datalogger) 3.Place the sample in a dark place at 20°C for 5 days. 4.Re-measure the oxygen level. 5.BOD is the difference between the two levels.
Why is the BOD important? Some species have a higher tolerance level of organic pollution and the low levels of oxygen which coincide with organic pollution. Therefore the population density of such species will be higher in polluted areas as there is less competition from other species.
Time of Year The date when organic pollutants is recorded is important. They are more dangerous in summer as solubility of oxygen decreases as water temperature increases. Therefore, less available oxygen. Also, if pollutants are heated before being released or already warm, this can have massive effects on the local river ecosystem.
Describe and explain an indirect method of measuring pollution levels using a biotic index. Another method to measure pollutants is to use a biotic index, such as the Trent Biotic Index. This does not measure the pollutant directly, but the impact it may have on the diversity of the ecosystem. Biotic Indices use BOD to estimate the impact as the levels of oxygen are detrimental to the abundance of living organisms.
Using indicator species to estimate river pollution Mayfly nymphs Oxygen Tubifex BOD Number of Individuals Level of contaminants Distance from effluence
5.3 Approaches to pollution management Outline the approaches to pollution management with respect to the process of pollution and strategies for reducing impacts Discuss the human factors that affect the approaches to pollution management Evaluate the costs and benefits to society of the World Health Organisation’s ban on the use of the pesticide DDT.
DDT (Dichlorodiphenyltrichloroethane) DDDDDE (Dichlorodiphenyldichloroethlyane) (Dichlorodiphenyldichloroethane) Thinning of Birds Eggs
Purpose To control lice and anopheles mosquito to reduce the spread of Thyphus and Malaria. Malaria accounts for 1 million deaths per year and 250 million diagnosed per year. Thyphus – leads to influenza like symptoms and muscular pain. Not fatal.
History of Use Introduced to eradicate Malaria by WHO in extensively used in farming as a pesticide. Although it killed many insects which were beneficial to farming as a whole Progressive banning of DDT in MEDCs. Internationally banned as a pesticide in many countries through the Stockholm Convention (1972) and restricted to disease control.
Impact of DDT Loss of DDT to the environment through runoff, evaporation and biodegradation. Half life of between 22 days and 30 years in some cases. Bioaccumulation Biomagnification ppm 0.04 x 10 4 ppm 0.2 x 10 5 ppm 2.0 x 10 6 ppm 20 x 10 7 ppm
Some studies suggest an: – Increased rate of asthma, diabetes, liver-, breast- and/or pancreatic cancer. – Increase risk of early pregnancy loss or premature births. – Increased rate of male infertility (2007 South Africa)
But... In countries where DDT has been used more the reduction of Malaria death rates have been reduced. – E.g. Ecuador % reduction in Malaria due to increased use of DDT.
Should DDT use continue to be used as an anti-malaria weapon?
5.4 Eutrophication Outline the process of eutrophication Evaluate the impacts of eutrophication Describe and evaluate the pollution management strategies with respect to eutrophication.
5.5 Solid Domestic Waste Outline the types of solid domestic waste Describe and evaluate pollution management strategies for solid domestic (municipal) waste.
5.5.1 Outline the types of solid domestic waste Municipal solid waste “Municipal solid waste consists of household waste, construction and demolition debris, sanitation residue, and waste from streets. This garbage is generated mainly from residential and commercial complexes.” Domestic Waste, Assam Science Technology & Environment Council, accessed
Pollution Management; Solid Domestic Waste, Environmental Systems and Societies, Andrew Davis and Garrett Nagle, p.239, 2010 CountryOrganicsPaper/ Board GlassMetalsPlasticsTextilesOthers Belgium Denmark Germany France Greece Ireland Italy Luxembourg Netherlands Portugal Spain
5.5.2 Describe and evaluate pollution management strategies for solid domestic (municipal) waste. ReductionReuseRecoverDispose