Environmental health • Definition: “the control of all those factors in man’ s physical environment which exercise or may exercise a deleterious effect on his physical development, health and survival
ًWHO organization • Define health as a state of complete physical , mental and social well being, not only the absence of the disease or infirmity
Practice of environmental health • Water sanitation • Refuse and garbage disposal • Sewage disposal • Air pollution (indoor and out door) • Injuries • Food hygiene • Vector control • Safety and health in hospital
Environment includes all those factors related to health that are external to human body, the individual has a limited control over these factors. Health hazards are classified as: Chemical, physical ,biological social and behavioural.
Aim and objectives • To inform or enlighten students about general health hazards in the environment such as,,,,,,,, • To be able at primary level to protect and prevent diseases due to pollution of water ,air and food • To develop awareness among medical students regarding currently emerging diseases related to environment such as bird flue incidents and dengue fever……..
Solid wastes • Solid wastes • Definition: “Solid wastes” is applied to unwanted or discarded waste materials from houses, street sweepings, industrial and agricultural operations arising from man’ activities.
Health aspects • The organic portion of solid wastes ferments and favor fly breeding • The garbage in the refuse attracts rats • The pathogens may conveyed to man through flies and dust • There is possibility of water pollution if rain water passes through deposits of fermenting refuse • There is risk of air pollution, if there is accidental or spontaneous combustion of refuse • Piles of refuse are nuisance from aesthetic point of view
Sources of refuse • Sources and types of refuse: • 1:Street refuse • 2:Market refuse • 3:Stable litter • 4:Industrial refuse • 5:Domestic refuse • 6:Agricultural
Types of refuse • Ashes: residues of combustion of solid fuels • Garbage: decomposable wastes from food • Rubbish : Non decomposable wastes • Debris • Dead animals • Hazardous wastes: “wastes that pose a potential hazards to humans or other living organisms because these wastes are non degradable or persistent in nature
Collection and disposal • Incineration • Open dumping • Domestic grinding for garbage • Controlled dumping or Sanitary land fills • Composting • Recycling
Advantages and disadvantages of the incineration • Combustion of breeding materials • Takes combined garbage and refuse • Can be very efficient and 24 h/day in large cities. • Cause air pollution, particulates and odour • High capital investment, high operational and maintenance cost
Advantages and disadvantages of open dumping • Hauling is only cost • Combined garbage and rubbish • Optimum for insects and rodents breeding • Air pollution from dump fires • Water pollution from leaching
Sanitary landfills Advantages • Combined collection • Low capital investment • Moderate operational cost • Land reclamation for restricted use • Adopted for small towns
Disadvantages • Land requirement • Require selected soil and cover • Require stand by fire control • leaching may add pollutant to ground or surface water sources
composting • Advantages • Conserves and recycles wastes • Provides humus for soil • Decomposition heat control flies • Aerobic action free of odour • Sewage sludge can be combined
Disadvantage • Require pre-sorting and grinding. • High capital investment and maintenance cost. • Require assured market for compost. • Require disposal of non compostables
Advantages and disadvantages of recycling • Recovery of usable and salable materials. • Conservation for energy • Limited to special wastes and selected materials • At the mercy of the market • Require special equipments. • Remainder must be managed
Sewage disposal (excreta disposal) • Proper disposal of sewage is a fundamental environmental health service without which there cannot be any state of improvement in the state of community health. • Human or animal excreta is a source of transmission of several diseases such as typhoid and paratyphoid fever, diarrhoeas, cholera, ascariasis, viral hepatitis ……
Treatment of sewage • Primary treatment • Screening • Removal of grit • Plain sedimentation.. • Secondary treatment • Trickling filter • Activated sludge • Digestive sludge
Basis of sewage treatment • Protection of water supplies. • Protection of human food to be eaten raw • Protection of shellfish and other aquatic life. • Protection of soil against pollution
Environmental protection agency (EPA) • Independent agency of USA government • Established 1970 to protect the environment • Establish standards for the quality of air and water . • inspection and monitoring of radiation levels in the environment • Monitoring global warming • Regulation and legislation for handling and Disposal of radio active materials