indicatororganisms.ppt

Indicator Organisms and Water Pollution Microbiology is very useful as a means of measuring how safe water is to drink Would you drink this water? Its colourless, odourless, tasteless just like normal water. Is it safe to drink? Microbiological tests and some chemical tests are used to establish this Water for sports or recreation Microbiology is also very useful in establishing if water is suitable for water sports or recreation Would you swim in this swimming pool? Is the water safe? What types of microbes would be present? Consequences of drinking contaminated water Diarrhoeal disease – cryptosporosis, E. coli, Gardia Inflammation of the colon Vomiting Hepatitis Cholera, Salmonella and E. coli poisoning Pneumonia Sometimes fatal Consequences of drinking contaminated water Skin infections Eye infections Ear, nose and throat infections Pneumonia Diarrhoea Tuberculosis Hepatitis Rarely death Which organisms should you look for? Is it necessary to test water for every possible dangerous organism? No It would simply take too much time and be too costly We test water for a selection of microorganisms that are most often found in faeces If they are present then it indicates that the water has been in contact with faeces and is most likely contaminated with dangerous bacteria, fungi and or viruses. What is an indicator organism? An organism which is used by man as a way to detect the presence of something which is dangerous to man Miners use canaries as indicator organisms in mines to detect the presence of toxic gas In water analysis we use some bacterial species as indicator organisms, in particular coliforms Why use indicator organisms in water analysis? It is not practical to examine water for the presence of all types or species of pathogenic organisms, bacteria, viruses and protozoa Indicator organisms are organisms associated with the intestinal tract of warm blooded animals including man Their presence indicates the water to be contaminated with