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Public health 1 MCS 210 Environment and Health

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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!
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