Environmental health.pptx edited.pptx for u

Well documented by our lecturer In federal university Dutse.

1. COMMUNITY MEDICINE DEPARTMENT, FEDERAL ENVIRONMENTAL HEALTH   UNIVERSITY DUTSE AUWAL GARBA   2024

2. OUTLINE Environmental sanitation Food Safety and Hygiene Solid Waste management Vector control Water quality and management Waste water Management Questions!!!!!

3. What is environmental sanitation? A collection of actions and policies aimed at improving or maintaining the standard of core environmental conditions affecting the well-being of people . Conditions include: a clean and safe water supply clean air efficient and safe waste disposal procedures protection of food from physical, chemical and biological contaminants and suitable housing in safe and clean surroundings

4. What is environmental sanitation? Contd. Environmental sanitation include: treatment and disposal of human, industrial and animal waste control of disease vectors provision of restroom facilities for personal hygiene. For environmental sanitation to be effective, these practices must be instituted on a community and individual basis.

5. What is environmental sanitation? Contd. Environmental sanitation involves: limiting the environmental contributors that spread disease. commercial food safety practices in public facilities such as farms and restaurants. hospital safety and efficient waste removal. Individuals or head of household are required to instill effective personal hygiene practices. Areas that do not have access to good environmental sanitation are susceptible to widespread pollution and proliferation of infectious diseases. Chadwick published a report in 1842 that was the first to detail that a lack of sanitation would lead to disease for humans.

6. Types of Sanitation There are different types of sanitation relating to particular situations, such as: Basic sanitation: refers to the management of human faeces at the household level. It means access to a toilet or latrine. Onsite sanitation: the collection and treatment of waste at the place where it is deposited. Food sanitation: refers to the hygienic measures for ensuring food safety. Food hygiene is similar to food sanitation.

7. Types of Sanitation Housing sanitation: refers to safeguarding the home environment (the dwelling and its immediate environment). Environmental sanitation: the control of environmental factors that form links in disease transmission. This category includes solid waste management, water and wastewater treatment, industrial waste treatment and noise and pollution control. Ecological sanitation: the concept of recycling the nutrients from human and animal wastes to the environment.

8. Water quality and management Water is an essential resource for life and good health A lack of water to meet daily needs is a reality today for one in three people around the world Globally, the problem is getting worse as cities and populations grow, and the needs for water increase in agriculture, industry and households

9. Sources of water Rain Surface water : Impounding reservoirs Rivers & streams Tanks, pond & lakes Ground water : Shallow wells Deep wells Springs

10. Physical water-quality parameters Physical parameters define those characteristics of water that respond to the senses of sight, touch, taste or smell. Suspended solids, turbidity, colour , taste and odour and temperature fall into this category.

11. Chemical water-quality parameters Chemical parameters are related to the solvent capabilities of water. Total dissolved solids, alkalinity, hardness, fluorides, metals, organics and nutrients fall into this category.

12. Biological water-quality parameters From the perspective of human use and consumption, the most important biological parameters are related to pathogens (those organisms capable of infecting or transmitting diseases to humans) i.e. viruses, bacteria, protozoa, helminths and blue-green algae.

13. Qualities of a good well Sited at least 30 metres & preferably uphill from any potential source of pollution Water-tight lining of at least 30f from surface Concrete platform (parapet) about 2f high surrounded by a concrete apron to drain the waste water away Water tight cover Water drawn to be drawn by a pump or at least a permanent bucket attached to the well

14. water treatment

15. General principles of water treatment Protection of sources Storage Sedimentation & coagulation Filteration Disinfection Boiling Distribution Quality control

16. Methods of water treatment The principal techniques used for treatment of public water are: Storage : sedimentation and clarification. Filtration : slow+rapid sand filters, micro-strainers, membrane filters. Disinfection : chlorination and ozonisation.

17. Storage Storage (sedimentation) allows impurities suspended in water to sink naturally to the bottom of a tank through the effects of gravity. Clarification uses chemicals such as aluminium sulphate (Camelford, 1998 !!!) to remove very fine suspended particles. The aluminium sulphate forms a precipitate when added to water, which coagulates with the suspended particles and then sinks to the bottom of the storage tank.

18. Filtration Filtration involves passing water through sand or a fine wire mesh, which removes particles. Other devices: rapid gravity, pressure or membrane filters. Membrane filters with <1 micron pores can strain out bacteria and give drinking water not requiring disinfecting.

19. Disinfection For large installations or supplies to the general public this is done by adding sterilizing agents i.e. chlorine, ozone or UV-light. In small installations, a small filter is fitted near the drinking water taps of a building and consists of either a disposable or permanent filter.

20. Other water treatments Other small-scale techniques include: - Carbon filtering (charcoal adsorbers). - Boiling water. - Distillation/desalination (condensed water vapour). - Reverse osmosis (mechanical pressure forces water through a semi-permeable membrane).

21. Methods of treatment depend on supplies and intended use. The treatments remove metallic salts, bacteria, turbidity, colouring odours and particles, which affect its taste. Water quality varies with the local geology (different whiskey tastes) and can be classified as hard, soft, acidic or alkaline.

22. Diseases Related to Water Water-borne Diseases Water-washed Diseases Water-based Diseases Water-related Diseases

23. Water-borne Diseases Diseases caused by ingestion of water contaminated by human or animal excrement, which contain pathogenic microorganisms

24. Include cholera, typhoid, amoebic and bacillary dysentery and other diarrheal diseases

25. Diarrheal Diseases Giardiasis (Protozoan) Cryptosporidiosis (Bacteria) Campylobacteriosis (Bacteria) Shigellosis (Bacteria) Viral Gastroenteritis (Virus) Cyclosporiasis (Parasite)

26. In addition, water-borne disease can be caused by the pollution of water with chemicals that have an adverse effect on health

27. Arsenic Flouride Nitrates from fertilizers Carcinogenic pesticides (DDT) Lead (from pipes) Heavy Metals

28. Water-washed Diseases Diseases caused by poor personal hygiene and skin and eye contact with contaminated Water These include scabies, trachoma typhus, and other flea, lice and tick-borne diseases.

29. These include scabies, trachoma, typhus, and other flea, lice and tick-borne diseases.

30. Water-based Diseases Diseases caused by parasites found in Intermediate organisms living in contaminated water Includes Schistosomiasis an Dracunculiasis Includes Schistosomiasis and Dracunculiasis.

31. Water-related Diseases Water-related diseases are caused by insect vectors, especially mosquitoes, that breed or feed near contaminated water.

32. They are not typically associated with lack of access to clean drinking water or sanitation services Include dengue, filariasis ,malaria , onchocerciasis, trypanosomiasis and yellow fever

33. Other Water-borne diseases Bathing Swimming Other recreational activities that have water contact Agriculture Aquaculture

34. The Problem ~80% of infectious diseases > 5 million people die each year > 2 million die from water-related diarrhea alone Most of those dying are small children

35. Other Consequences Lost work days Missed educational opportunities Official and unofficial healthcare costs Draining of family resources

36. Global Governments Communities Individuals Control & Prevention

37. Education Issues Hygiene education Good nutrition Improvements in habitation and general sanitation Higher education training in water-related issues

38. Global Surveillance Public health infrastucture Standardized surveillance of water-borne disease outbreaks Guidelines must be established for investigating and reporting water-borne diseases

39. Communication and the Media Impacts at all levels Very powerful, when others fail

40. General Guidelines Avoid contacting soil that may be contaminated with human feces. Do not defecate outdoors. Dispose of diapers properly.

41. Wash hands with soap and water before handling food. When traveling to countries where sanitation and hygiene are poor, avoid water or food that may be contaminated. Wash, peel or cook all raw vegetables and fruits before eating.

42. FOOD HYGIENE/SAFETY Definition: Food Safety/ Food Hygiene is defined as all conditions and measures that are necessary during production, processing, storage, distribution and preparation of food to ensure that it is safe, sound ,wholesome and fit for human consumption. (WHO)

43. FOOD HYGIENE AND SAFETY Food Hygiene :  can be described as practices in food handling that help to keep food clean and safe to eat in order to avoid food poisoning due to bacterial, fungal or viral contamination of food. Food safety : can be defined as the absence of adverse health effects following food consumption

44. Exposure of vegetables Exposure of staple food

45. Exposure of fish Exposure of meat

46. Preparation of food Serving food

47. Waste disposal Cleaning of dishes

48. PRINCIPLES OF FOOD HYGIENE Personal Hygiene: Wash hands: before commencing work, after using the toilet, between different work tasks especially after handling raw foods. Wear clean protective clothing including a suitable, effective hair covering. Keep all cuts, boils etc, covered with waterproof dressings. Refrain from smoking Keep fingernails short. Do not cough or sneeze over food. Do not touch or sneeze over food. Do not touch the mouth, nose or face – at least without washing your hands afterwards. Report any illness which may be food poisoning to the supervisor and consult your doctor.

49. PRINCIPLES OF FOOD HYGIENE 2. Food Storage: A good system of stock rotation should be operated through which the oldest stock is used. Stock should be kept at least a few inches off the ground to give a circulation of air and to enable insect and rodent infestations to be detected. Food stores must be adequately ventilated and be kept at a temperature below 10 o C. Refrigerators, Chillers, Freezers etc. must be regularly checked for operating efficiency against their designed temperature range. Keep food either hot, i.e. about 63 C, or cold i.e. below 10 o C

50. PRINCIPLES OF FOOD HYGIENE 3. Cross Contamination: Avoidance of the contamination of a ready–to-eat risk food by another food either directly by way of a transmitting agent is of paramount importance. Keep raw and cooked foods separate at all times including in storage. Use separate surfaces, utensils and other equipment for the preparation of raw and cooked food. As far as possible, separate staff should be used for handling raw and cooked food. Cleaning and sterilization of food slicing machinery should be given attention because of the potential for cross-examination Avoid reheating of foods if at all possible. Foods which have to be reheated should be brought to temperatures above 63 o C.

51. PRINCIPLES OF FOOD HYGIENE Temperature Control : Factors such as moisture, food, time & correct temperature facilitates the growth of food poisoning organism. Temperature control is based on time & correct temperature and in simple terms requires risk foods to be kept as short a time as possible at temperatures which are conducive to bacterial growth, i.e. between 10 o C and 63 o C. Below 10 o C : No bacterial growth ; Above 63 o C: Pathogenic organisms are destroyed. Food processing temperatures are critical to the production of a safe product and should always be checked where risk foods are involved. Premises: Layout Floors Walls Lighting

52. PRINCIPLES OF FOOD HYGIENE 5. Premises (contd.) : Ventilation Refuse 6. Equipment: Equipment in food premises must be: Constructed so as to facilitate ease of cleaning and be free from inaccessible points; Non-absorbent; Placed in such a way that cleaning is possible on all sides; Well maintained. Cleansing: The fundamental objective in food premises is the killing of pathogenic organisms and elimination of situations in which they might thrive. Cleaning of the structure, equipment and working surfaces should be on a planned program based on principle of good house keeping.

53. PRINCIPLES OF FOOD HYGIENE 7b. Cleansing materials: Detergents: Reduce surface tension & remove grease, thus enabling sterilants to act effectively. Sterilants or Disinfectants: Kill bacteria. Examples: Hypochlorites, Iodophors, Quaternary Ammonium Compound (QAC), Phenolic disinfectants. PPE in Food Premises: Hair Net Hand Gloves Aprons/Hygienic Wear

54. FOOD CONTAMINATION Food contamination: It is the presence of an infectious agent on food substance. Food can be contaminated through: Production Processing Handling Transportation Eating There are 5 agents through which food can be contaminated: Microorganisms Toxins (Endo & Exo toxins): Exotoxins: toxins released on the food by microorganism. Endotoxins: microorganisms grow inside the food and produces toxins in its cells. Chemicals: Chemicals added illegally or ignorantly. They are normally; Preservatives such as Vinegar, Salt, Sugar, tartaric acid etc. some food industries use sodium benzoate for long time preservation. This has been known to be carcinogenic.

55. FOOD CONTAMINATION (contd) Artificial sweetners: Sugar (10kg/head/per year is recommended). 25-30g/day/person. Cyclamates: Are derived from coal tar, by-product petroleum. This is a product of benzene hydrocarbon. it can cause cancer. Saccharine: It is also carcinogenic, but it is still used as sweetner. It causes cancer of the kidney. Flavours and Colours: They are products of Hydrocarbon materials. Adulteration: Adulterated products are harmful. Oil used for frying more than 3 times will be contaminated and harmful. Monosodium glutamate: Glutamate is not easily metabolisable by the cells. It causes Chinese syndrome. Symptoms –Cramps, body pains. It can cause cancer of the bone, kidney etc. Limited use of this substance should be encouraged .

56. FOOD CONTAMINATION (contd) Natural Toxins: Some food naturally contains toxin materials. E.g. Groundnuts Afflotaxins Fishes Accumulates heavy metals Cassava Cyanides Mushrooms Alkaloids; this cannot be destroy by heat. This results in abdominal cramps. Potatoes (Irish) Solanin is a form of alkaloides . It can be destroy by heat Note: The toxins are protective materials for the plants. Parasites: Such as Tape worm ( Taeniasis Trachuriasis ). All produce toxins in the food. NOTE: Types of food contamination: Biological, Chemical and physical (stones, hair, glasses etc.)

57. BACTERIAL CONTAMINATION (VEHICLES AND ROUTES) Clean food can be contaminated by bacteria from four main sources - - the people present in the workplace and their clothing. - other food that is already contaminated. - dirty kitchen or work premises and equipment. - insects and vermin. Sometimes, harmful bacteria pass directly from the source to high risk food, but, usually they rely on other things to transfer them to food. These things are called Vehicles .

58. Indirect contamination using an intermediate vehicle is the most common, e.g.- the movement of bacteria from the intestine of a food handler to food via unwashed hands, after using the toilet. Where contamination is passed from raw food to high risk food via for example, a cutting board, this is known as Cross Contamination . The path that bacteria use to move from the source to the food, is known as the Route .

59. Food Poisoning Food poisoning : any condition in which a food causes a toxic reaction, whether as a result of a toxin naturally present in the food (for example, green or sprouting potatoes, partially cooked red kidney beans, many mushrooms, and so on); a toxin acquired by the food as a result of natural accident (such as contamination of fish or shellfish with toxins from dinoflagellate organisms in plankton—the so-called red tide); fungal spoilage leading to the production of mycotoxins in the food; or

60. Food Poisoning (contd) contamination of the food with toxins during agricultural processing (for example, pesticide residues) or food processing (such as accidental contamination with industrial chemicals). However, the term is generally reserved for gastrointestinal disease resulting from bacterial (or sometimes viral) contamination of foods food poisoning may occur within 1-36 hours of eating contaminated food. symptoms normally last 1-7 days and may include one or more of the following: abdominal pain, diarrhoea , vomiting, nausea, fever, gastroenteritis

61. Incubation periods of food poisoning bacteria Salmonella typhi : 12-36 hours Staphylococcus : 2-6 hours Clostridium perfringes : 8 – 22 hours Streptococci, coliform bacilli and aerobic sporing bacilli: 4-36hours Clostridium botulinum : 24-72 hours

62. Causes of Food Poisoning Inadequate cooking of contaminated raw food, and inadequate reheating of pre-cooked food, so that the temperature is not sufficiently high to kill the bacteria Keeping cooked food at temperatures that favour the growth of bacteria Cross-contamination between raw and cooked food Poor personal hygiene in food handlers

63. PREVENTION/CONTROL OF FOOD POISONING Protect food from contamination by: - keep food covered whenever possible - do not use unsuitable, defective or dirty equipment - do not use dirty wiping cloths, disposable preferable - only handle food when unavoidable (use tongs, plates, & trays) - separate raw and cooked food at all stages of preparation, storage and distribution - prevent insects, animals and birds from entering food rooms or come in contact with food

64. - store food in rodent-proof containers and ensure lids are tightly replaced after use - protective clothing for all food handlers - maintain high standard of personal hygiene - use correct cleaning and disinfection procedures - refuse disposal - purchase food from reputable sources - environmental sanitation (clean environment with good water supply and sanitation)

65. Prevent bacterial within food from multiplying by: - employing appropriate storage temperature (store food out of danger zone- <5 o C & >63 o C) - using suitable preservative (salt, sugar). - Do not allow dry foods to absorb moisture - other methods: canning, freezing, drying and dehydration, smoking(?)

66. Destroy those bacteria within food (disinfection) by: - thorough cooking, heat processing such as pasteurization, sterilization (e.g. UV) or canning Inspection of food premises Basic food hygiene education for food handlers Medical screening for food handlers

67. Good manufacturing practices (GMPs) Adequate quality control using the Hazard Analysis Critical Control Point (HACCP) system. Legislation

68. FOOD-BORNE DISEASES Defined as a disease, usually either infectious or toxic in nature, caused by agents that entered the body through the ingestion of food. Food borne diseases may be classified as: Food borne intoxications Due to naturally occurring toxins in some foods Lathyrism ( beta oxalyl amino-alanine) Endemic ascitis (Pyrrolizidine alkaloids) 2. Due to toxins produced by certain bacteria. Botulism Staphyloccus poisons 3. Due to toxins produced by some fungi Aflatoxin Ergot Fusarium toxins

69. FOOD-BORNE DISEASES Food borne chemical poisoning Heavy metals, e.g., mercury ( usually in fish), cadmium (in certain shell fish) and lead ( in canned food). Oils, petroleum derivatives& solvents (e.g., Trycresyn phosphates or TCP) Migrant chemicals from package materials Asbestos Pesticides residues (DDT, BHC).

70. FOOD-BORNE DISEASES Food borne infections GROUP EXAMPLES OF ILLNESS IN EACH GROUP Bacterial Diseases Typhiod fever, Paratyphoid fever, Salmonellosis , Staphylococcal intoxication, Cl. Perfringens illness, Botulism, B.cereus food poisoning, E.coli diarrhoea , Non-cholera vibrio illness, V. parahaemolyticus infection, Streptococcal infection, Shigellosis Brucellosis Viral diseases Viral hepatitis, Gastroenteristis Parasites Taeniasis Hydatidosis, Trichinosis, ascariasis, Amoebiasis, Oxyuriasis

71. AGENCIES INVOLVED IN ENSURING FOOD HYGIENE NAFDAC SON Ministry of Environment Federal and State Public Health Laboratories

72. SOLID WASTE MANAGEMENT Waste can be defined as any reject material that may be discarded or disposed of or reutilized in any other resourceful way Sources of wastes Domestic: household refuse Municipal: market and abattoir Agricultural: plants and animal remains Industrial: solid waste from industries Hazardous wastes: hospital

73. Sources

74. Characteristics of wastes: A. Physical Characteristics Moisture content Density Weight Temperature B. Chemical characteristics pH C, N,P, K, heavy metals

75. Characterization of the physical components Domestic and Municipal waste: Leaves Paper Plastics/nylon Glass Tin Metals Wood

76. Effects of wastes Environmental: Air pollution, water pollution, Soil pollution, Nuisance and Vectors Health Effects: Nausea, Irritation, Skin rashes, Poisoning, Injuries and Cancers

77. WASTE LIFE CYCLE GENERATION DISPOSAL HANDLING TREATMENT STORAGE TRANSPORTATION

78. WASTE MANAGEMENT Waste: Is any material or substances that do not have immediate economic value at that particular point in time and then becoming a nuisance to the disposer. Waste management is therefore a practice to gradually reduce wastes with the ultimate aim of eliminating those that have the potential to cause harm to people and the environment. Solid Waste Management The systematic administration of activities that provide for the collection , source separation, storage, transportation , transfer , processing , treatment , and disposal of solid waste .

79. Solid Wastes

80. BASIC PRINCIPLES OF WASTE MANAGEMENT 5 Basic Steps: WASTE INVENTORISATION :- Taking inventory of all waste generated i.e. source of waste, degree of waste generated, form of waste, type /category of waste. 2. WASTE CHARACTERISATION :- Characterization of waste based on physical, chemical and toxicological properties of waste. 3. WASTE SECREGATION :- Selective separation of waste i.e. Hand picking/sorting at Source. WASTE MINIMIZATION :- This involves the 5Rs. i.e. (1) Reduce (2) Reuse (3) Recycle (4) Recovery (5) Reject 5. WASTE TREATMENT:- This involves physical / biological treatment.

81. Waste management Reduce, Reuse, Recycle, Reject and Resource Recovery Source separation and segregation Collection, Transportation and Treatment Treatment methods Composting Pulverization Pyrrolysis Incineration

82. Waste Management Pyramid

83. Disposal methods Landfill Sea dumping Open dumping Management of waste involves a careful selection of methods dependent on cost, availability of facilities, personnel and environmental factors

84. Integrated waste Management

85. VECTOR CONTROL Vectors are agents of disease transmission They are divided into : Insect vectors and Non insect vectors Vectors are associated with filthy environments They thrive under favourable ecological conditions viz Temperature Humidity pressure

86. Examples of Insect vectors: Flies Mosquitoes Cockroaches Ticks Examples of non insect vectors Rats Rodents

87. Effects associated with vectors Environmental Effects Nuisance effects Health Effects Diseases of Public Health Importance Malaria Typhoid Trypanosomiasis

88. Vectors and diseases likely to be present in emergency settlements Vector Main diseases Mosquitoes: Malaria, yellow fever, dengue, viral encephalitis, filariasis . Houseflies: Diarrhoea , dysentery, conjunctivitis, typhoid fever, trachoma. Cockroaches: Diarrhoea , dysentery, salmonellosis , cholera. Lice: Endemic typhus, pediculosis , relapsing fever, trench fever, skin irritation. Bedbugs: Severe skin inflammation. Triatomid bugs: Chagas ’ disease. Ticks: Rickettsial fever, tularaemia , relapsing fever, viral encephalitis, borreliosis . Rodent (mites): Rickettsial pox, scrub typhus. Rodent (fleas): Bubonic plague, endemic typhus. Rodents Rat bite: fever, leptospirosis , salmonellosis , melioidosis .

89. New strategies for prevention and control of vector-borne diseases are emphasizing "Integrated Vector Management" – as an approach that reinforces linkages between health and environment, optimizing benefits to both. The most deadly vector borne disease, Malaria, kills over 1.2 million people annually, mostly African children under the age of five. Dengue fever, together with associated dengue haemorrhagic fever (DHF), is the world's fastest growing vector borne disease

90. Poorly designed irrigation and water systems, inadequate housing, poor waste disposal and water storage, deforestation and loss of biodiversity All these factors contribute to the most common vector-borne diseases including malaria, dengue and leishmaniasis .

91. These include environmental management strategies that can reduce or eliminate vector breeding grounds altogether through improved design or operation of water resources development projects. Use of biological controls (e.g. bacterial larvicides And larvivorous fish) that target and kill vector larvae without generating the ecological impacts of chemical use.

92. IVM makes judicious use of chemical methods of vector control, such as indoor residual sprays, space spraying, and use of chemical larvicides and adulticides; these reduce disease transmission by shortening or interrupting the lifespan of vectors. IVM provides a framework for improved personal protection/preventive strategies that combine environmental management and chemical tools for new synergies; e.g. insecticide-treated nets (ITNs).

93. Trials using insecticide-treated bednets in some malaria-endemic African countries have shown very substantial reductions in child and infant mortality . IVM also supports effective, accessible and affordable disease diagnosis and treatment within the framework of a multi-disease control approach.

94. Liquid wastes Effluent channel Treatment basin

95. Effluent conduit Effluent discharge

96. Sources of Wastewater in Industry Process wastewater Domestic wastewater Recreational wastewater Characteristics of wastewaters Composition determined source and activity Vary in physical, chemical and biological characteristics

97. Problems associated with Waste water Nuisance effect Air pollution Water pollution Soil pollution Vector infestation Proliferation of weeds Algal blooms( Eutrophication ) Water way accidents

98. Effluent characteristics Volume pH Total Suspended Solids(TSS) Biochemical Oxygen Demand(BOD) Chemical Oxygen Demand(COD) Inorganic substances Organic substances Affected by the flow rate and dilution factors

99. Management Options Reduce Reuse Recycle Resource recovery Decentralized systems Oxidation ponds Aerated lagoons Septic tanks

100. EXCRETA DISPOSAL AND SANITATION To improve health, high priority should be given to observing the principles of sanitary excreta disposal. Children should be taught: how to use excreta disposal facilities, about the dangers of defaecating on the ground and about the importance of thorough hand washing with soap or ash after contact with excreta Appropriate facilities for excreta disposal is a basic need.