MCS 210 ENVIRONMENT HEALTH MRS. GETRUDE KANGWA-SIAME OUTLINE •Learning outcome •Definition of terms •concept of health and disease. •Determinants of health •Interaction of agent, host and environmental factors •Components of environment LEARNING OUTCOMES At the end of the lecture the students should be able to: 1. Overview of Environmental Health 2. Define key terms 3. Describe the influence of environment on human health 4. Explain the physical, biological and psychosocial environment and understand their impact on health. DEFINITION OF TERMS Health “Health is a state of complete physical, mental, social and spiritual well-being and not merely the absence of disease or infirmity.” in recent years the statement is amplified to include, “The ability to lead a socially and economically productive life.” Holistic concept of health: this concept recognizes the strength of social, economic, political and environmental influences on health DEFINITION OF TERMS • ENVIRONMENT: All that which is external to man is the environment. the concept of environment is complex. The external environment or the macro-environment is said to be responsible for millions of preventable diseases originating in it. Micro-environment is the domestic environment in which man lives The term internal environment is some time used for the environment inside the body External environment: “All that is external to the individual human host, living and non-living, and with which he is in constant interaction”. DEFINITIONS TERM CONT.… • The environment is all external conditions, circumstances, and influences surrounding and affecting the growth and development of an organism or community of organisms. • Environmental health is the study and management of environmental conditions that affect the health and well-being of humans. • Environmental health defined as “comprising those aspects of human health, including quality of life, that are determined by physical, chemical, biological, social and psycho-social factors in the environment. it also refers to the theory and practice of assessing, correcting, controlling and preventing those factors in the environment that can potentially affect adversely the health of the present and future generation.(WHO, sofia, 1993). ENVIRONMENTAL HEALTH OVERVIEW 23/05/2023 7 Environmental hazards • Environmental hazards may be biological, chemical, physical, psychological, sociological, or site and location hazards. • “The World Health Organisation (WHO) defines Environmental Health as comprising those aspects of human health, including quality of, that are determined by physical, biological, social and psychological factors in the environment”. • Environmental health addresses all the physical, chemical, and biological factors external to a person, and all the related factors impacting behaviours. 23/05/2023 8 • It encompasses the assessment and control of those environmental factors that can potentially affect health. • It is targeted towards preventing disease and creating health-supportive environments. ENVIRONMENT AS AN ASPECT OF 9 PUBLIC HEALTH 23/05/2023 • Environmental Health is the aspect of public health concerned with all the factors, circumstances and conditions in the environment or surrounding of human (i.e. air, water, land, housing etc.) that can exert an influence on human health and well being (Amadi, 2011). 23/05/2023 COMPONENTS OF 10 ENVIRONMENTAL HEALTH • According to EHORECON (2007), components of Environmental Health include: (1) Waste management (2) Food hygiene and control (3) Pest and vector control (4) Environmental health control of housing and sanitation (5) Epidemiological investigation and disease control (6) Air quality management (7) Occupational health and safety (8) Water resources management and sanitation COMPONENTS OF ENVIRONMENTAL HEALTH CONT. 23/05/2023 (9) Noise control (10) Protection of recreational environment (11) Radiation control and abatement (12) Educational activities (health promotion and education) (13) Promotion and enforcement of environmental quality standards. (14) Collaborative efforts to study the effects of environmental hazards (research). (15) Environmental Impact Assessment (EIA) and (16) Management of emergency situations (disaster, flooding, disease outbreaks) etc. DETERMINANTS OF HEALTH: • Physical environment • Income and social status • Education • Social support networks • Culture • Personal behavior • Genetics. • Health services • Gender ENVIRONMENTAL IMPACT ENVIRONMENT (PHYSICAL, BIOLOGICAL AND PSYCHOSOCIAL) HUMAN ACTIVITIES HEALTH OF INDIVIDUAL HUMAN INTERACTION AND THE ENVIRONMENT • The human living environment consists of home, work and recreational environments. • The interaction between these environments and human activities results in various types of hazards that may adversely affect human health. (Source: adapted from Bassett, 2004) HUMAN–ENVIRONMENT INTERACTION MODEL Human Activities Ambient Environment Development : • Economic • Social Air, Soil, Water Ecology Residues/ wastes Hazards CONT… CONT.… • In diagrams above , the two arrows lying between ‘human activities’ and ‘ambient environment’ indicate the relationship between them, i.e. that development requires resources from the environment (forward arrow) and, as a result, waste could be generated as a by-product (backward arrow). • In fact, there are three possible types of interaction: humans can affect the environment, the environment can affect humans, and humans and the environment can co-exist (where they sustain each other). • The red arrows in the figure indicate the negative effect if the generated waste is not properly handled. • This affects the environment in the form of pollution of air, water, etc., and can have a negative influence on development. COMPONENTS (CONSTITUENTS) OF ENVIRONMENT: Physical: air, water, soil, housing, climate, geography, heat, light, noise, debris, radiation, etc. Biological: man, viruses, microbial agents, insects, rodents, animals and plants, etc. Psychosocial: cultural values, customs, beliefs, habits, attitudes, morals, religion, education, lifestyles, community life, health services, social and political organization. 1. BIOLOGICAL HAZARDS These are living organisms or their products that are harmful to humans a. Water-borne diseases are diseases that are transmitted in drinking water 1. Examples are polio virus, hepatitis a virus, salmonella, shigella, cholera, amoebic dysentery, giardia, and cryptosporidium. 2. These disease organisms are shed into the water in feces, and can produce illness in those who consume untreated, contaminated water. 3. Our water treatment facilities are usually able to purify water by removing these agents or killing them by disinfecting the water. CONT.…. B. FOOD-BORNE DISEASES are diseases transmitted in or on food • Examples of food-borne agents are the bacteria salmonella, escherichia coli 0157:h7, as well as other agents. • To protect against food-borne diseases, environmental health officers and from local health inspector from public health departments MoH and Local Authorities routinely inspect food service establishments (restaurants) and retail food outlets (supermarkets) to verify that food is being stored and handled properly. C. VECTOR-BORNE DISEASES VECTOR-BORNE DISEASES are those transmitted by insects or other arthropods. • Examples are malaria and yellow fever transmitted by mosquitoes and plague transmitted by fleas. • Improper environmental management can cause vector-borne disease outbreaks. 2. CHEMICAL HAZARDS Chemical hazards - result from mismanagement or misuse of chemicals resulting in an unacceptable risk to human health. a. Pesticides are chemicals that have been manufactured for the purpose of reducing populations of undesirable organisms (pests) • Examples of categories of pesticides are herbicides and insecticides. • Most pesticides kill non-target organisms as well as the target, or pest species. • The wise use of pesticides can protect human health and agricultural crops. • Misuse of pesticides can result in illness and death. • Some of the pesticides developed earlier in the 20th century, such dichlorodiphenyltrichloroethane (DDT), were persistent, that is they remained in the environment for months or years after their initial use. • Newer pesticides are less persistent in the environment. B. ENVIRONMENTAL TOBACCO SMOKE (ETS) • Environmental tobacco smoke (ETS) is an environmental hazard produced by millions peoplet that smoke • Diseases associated with ETS include lung cancer and perhaps heart disease. • ETS classified as carcinogen. • Smoking has been increasingly restricted from public buildings and from many private work sites. • Regulation of smoking seems to be the best approach to controlling this pollutant C. LEAD Lead is a naturally occurring element that is used in the manufacturing of many industrial and domestic products 1. Health problems associated with the over exposure to lead are anemia, birth defects, bone damage, neurological damage, kidney damage, and others. 2. Exposure is by ingestion and inhalation. 3. Children are particularly at risk from eating peeling lead paint. 4. The prevalence of very high blood lead levels among young children declined significantly between 1984 and 1994 primarily because the removal of lead from gasoline. 5. Occupational exposure is a major source of lead intake for adults. 6. Solutions for the prevention of lead poisoning include education, regulation, and prudent behavior. 3. PHYSICAL HAZARDS Physical hazards: include airborne particles, humidity, equipment design and radiation a. Radon contamination results from over exposure to radon gas. Radon gas arises naturally from the earth and sometimes occurs at dangerous levels in buildings and homes. Breathing in radon gas can cause lung cancer. b. ultraviolet radiation reaches humans as short wave length energy that can damage cells by ionization. 1. One result of over exposure to UV radiation is skin cancer. 2. People should reduce their exposure to UV radiation. Stay in side Wear protective clothes or sunscreen CONT.…. 4. Psychological hazards: are environmental factors that produce psychological changes expressed as stress, depression, hysteria. 5. Sociological hazards: are those that result from living in a society where one experiences noise, lack of privacy and overcrowding. a. population growth may be a sociological hazard. 1. Principles a. Growth of living populations can be expressed as a curve with a lag phase, log phase and equilibrium phase. b. when environmental resources can support no further growth, the population has reached the equilibrium phase and the environment is said to be at its carrying capacity Environmental Health Services Biological Hazards Living Environment Home Work Environment Environment Recreational Environment Chemical Hazards Physical Hazards Social Hazards Psychosocial Hazards Source: Basset, W.H (2004) Contributions of Environmental Health Practitioners: by assessing correcting and preventing impact of hazards others a. Natural disasters are geographical and meteorological events of such magnitude and proximity to communities that they produce significant damage and injuries. 1. Examples are cyclones, earthquakes, floods, and volcanic eruptions. 2. The magnitude of devastation of these events can sometimes be great. 3. biological, psychological and sociological hazards may increase following a natural disaster. 4. DMMU and Local Authorities often provide help to clean up the damage and prevent a biological, psychological or sociological disaster from following a physical one. CONCEPTS AND PRINCIPLES IN HYGIENE AND ENVIRONMENTAL HEALTH 1. Environmental Health and Disease Transmission. 2. Consider diarrhoea, which is a symptom of many common diseases, as a means to understand the concept of disease transmission, the role of environmental health and the framework for hygienic improvements PATHWAYS OF DIARRHOEA TRANSMISSION. • The source of diarrhoea is the agent or carrier who discharges infected faeces to the environment. To remember the possible pathways we can use the six ‘F’s: • Faeces: resulting from defecation. • Fluids: through contaminated water and other contaminated liquids. • Fingers: contaminated fingers transmit diseases. • Flies: all sorts of animals such as flies can carry and transmit diseases. • Fomites or fields: fomites are inanimate objects that carry the infectious agent (e.g. dishes, cups and other contaminated surfaces in contact with food or water). • Food: infected by fluids, flies, fingers or fomites and then eaten. DISEASE TRANSMISSION Source of 1.2(a): adapted from WHO, 1998, PHAST step-bystep guide) ENVIRONMENTAL HEALTH AND DISEASE TRANSMISSION Source of 1.2(a): adapted from WHO, 1998, PHAST step-bystep guide) ENVIRONMENTAL RISK FACTORS • You have learnt that infectious agents play a part in the transmission of disease. • Infectious agents are pathogenic (disease-causing) bacteria, viruses, fungi, protozoa and parasites. • To cause a disease, they must be introduced into our bodies. • The environmental conditions and practices that facilitate the carrying of such infectious agents into our bodies are termed environmental risk factors. • A good example is drinking water, contaminated by human faecal matter that contains these infectious agents. • When this water is consumed, we are likely to get diarrhoeal diseases. CONT.. • There are other ways that infectious agents can get into our bodies; e.g, the air we breathe can be contaminated by droplets that come out of a patient’s lungs when they breathe or cough. • TB and pneumonia are droplet-related infections that are transmitted in this way. • There are also diseases and conditions that are not caused by pathogenic organisms, but are caused by other environmental risk factors, which may be due to chemicals or physical hazards such as noise. TABLE 1: MAJOR ENVIRONMENTAL RISK FACTORS WITH RELATED DISEASES Environmental risk factors Related diseases and conditionsAND CONDITIONS Contaminated water, lack of latrines, Diarrhoeal diseases, trachoma, schistosomiasis, ascariasis, poor hand washing, inappropriate solid trichuriasis, hookworm, typhoid fever, relapsing fever waste management, open defecation, vector infestation Indoor air pollution Chronic obstructive pulmonary disease, lower respiratory infections, lung cancer Outdoor/ambient air pollution Respiratory infections, cardiovascular diseases, lung cancer General environmental hazards (climate, mosquitoes, nutrition) Diarrhoeal diseases, malnutrition, malaria and other vector-borne diseases; heat exhaustion Environmental hazards in workplaces (excess noise, heat, dust, chemicals) Injuries, hearing loss, cancer, asthma, back pain, chronic obstructive pulmonary disease COMPONENTS OF HYGIENE AND Description Concerns ENVIRONMENTAL HEALTH Personal hygiene Hygiene of body and clothing Water supply Adequacy, safety (chemical, bacteriological, physical) of water for domestic, drinking and recreational use Human waste disposal Proper excreta disposal and liquid waste management Solid waste management Proper application of storage, collection, disposal of waste. Waste production and recycling Vector control Control of mammals (such as rats) and arthropods (insects such as flies and other creatures such as mites) that transmit disease COMPONENTS OF HYGIENE AND ENVIRONMENTAL HEALTH Food hygiene Food safety and wholesomeness in its production, storage, preparation, distribution and sale, until consumption Healthful housing Physiological needs, protection against disease and accidents, psychological and social comforts in residential and recreational areas Institutional hygiene Communal hygiene in schools, prisons, health facilities, refugee camps, detention homes and settlement areas Water pollution Sources, characteristics, impact and mitigation Occupational hygiene Hygiene and safety in the workplace ENVIRONMENTAL HEALTH • As explained above, the main aim of Environmental health therefore is to provide and promote healthy environments. Studies have shown that people who live healthy styles live longer. “Environmental Health constitutes six pillars of Environmental Health profession and these are: 1. Community health 2. Pollution control 3. Built Environment 4. Food hygiene and safety 5. Occupational health and safety and 6. professional over-arching competences and skills, including: • The legislation on environmental health, including legal directives and enforcement, powers of entry and due diligence of defense and procedures of abatements etc. • Hazard Analysis CONT.…. • Critical Control Point (HACCP) Principles • Inspection and Reports • Risk assessment and • Environmental Health Impact Assessment • All these equip and help EHPs to identify, assess, control and prevent environmental health hazards that can potentially affect adversely the health of the present and future generations. THE ROLE OF ENVIRONMENTAL HEALTH IN PUBLIC HEALTH • Environmental health is a part of public health where the primary goal is preventing disease and promoting people’s health. • Environmental health is associated with recognizing, assessing, understanding and controlling the impacts of people on their environment and the impacts of the environment on the public. • The role of the environmental health, therefore, includes the following functions of public health: ENVIRONMENTAL FUNCTIONS a. Assessment • Monitor environmental and health status to identify and solve community health problems. • Diagnose and investigate environmental health problems and health hazards in the community. b. Policy Development • Inform, educate, and empower people about environmental health issues. • Mobilize community partnerships and actions to identify and solve health problems. • Develop policies and plans that support individual and community environmental health efforts. ENVIRONMENTAL HEALTH FUNCTIONS IN PUBLIC HEALTH c. Assurance • Enforce laws and regulations that protect environmental health and ensure safety. • Link people to needed personal health services and assure the provision of health care when otherwise unavailable. • Assure a competent environmental health and personal healthcare workforce. • Evaluate effectiveness, accessibility, and quality of personal and population-based health services. • Research for new insights and innovative solutions to health problems. ENVIRONMENTAL HEALTH FUNCTIONS IN PUBLIC HEALTH Source: Centers for Disease Control and Prevention HEALTH INTERVENTIONS MODEL • Health intervention models for the prevention and control of communicable diseases. • The clinical intervention model focuses on the treatment of patients, while the public health intervention model concentrates on the maintenance of health through education and keeping the environment safe. • The red arrows indicate the points of intervention. HEALTH MODEL Health Population Environmental /Exposure Disease/ Condition Public Health intervention Model : targets attaining safe environmental Death ACKNOWLEDGEMENT Dr. Ayesha Humayun Assistant Professor & Public Health Consultant At Community Health Science College Reference Series, S.T., 1998. Phast Step-by-step Guide: A Participatory Approach For The Control Of Diarrhoeal Disease (Phast-sida-undp-wb-who, 2000, 137 P.). Morris, G.P., Beck, S.A., Hanlon, P. And Robertson, R., 2006. Getting Strategic About The Environment And Health. Public Health, 120(10), Pp.889-903 Marmot M, Wilkinson R, Editors. Social Determinants Of Health. Oup Oxford; 2005 Oct 13. Marmot, M., Allen, J., Bell, R., Bloomer, E. And Goldblatt, P., 2012. Who European Review Of Social Determinants Of Health And The Health Divide. The Lancet, 380(9846), Pp.1011-1029. Thank you!
