COURSEWARE
ON
ECOLOGY & HEALTH
ECH 656
by
Dr O.I. Musa
October 2011
Human Environment
 Human environment: is the general surroundings of man and consist of the
physical, biological and social components
Physical Environment
 Non-living component of man’s environment
 E.g. air, water, food, light, heat, noise, radiation
 All affects man directly or indirectly
 Directly – man needs air, water, food to survive
 Indirectly- light, health, noise, radiation affect man’s health
Biological Environment
 Include all living components of man’s environment, e.g. plants, animals, and
micro-organism (virus, bacteria, fungi etc)
 Existent of this component depends on large extent on the physical environment
e.g type of plants/animal depends of vegetable ……..weather, survival on
microbes depend on water, temperature etc
Social Environment
 Consist of man –man interactions-social-cultural practices belief, cultures, values
 Major effect is on the psych-psychological effect
i.e mental health
 social environment affect health positively and negatively
Man through his activities, actions and interaction effects changes in the environ which
may lead to environmental pollution
Environmental Pollution: Is defined as the unfavorable alteration of our surrounding
largely resulting from man’s actions leading to creation of environmental stress which
may influence man’s health
IMPACTS OF MAN ON THE ENVIRONMENT
 Man is the most important agent of change in the ecosystem
 Man impact can be deliberate or accidental, also direct or indirect
 These impact have result because of man activities
Impact include:1. Deforestation – farming, fire, timbre, overgrazing
 Change in Biomass
 Forest areas have been replaced other variable biomass composed of agricultural
crops, grass, scrubs, desert etc
Effect of deforestation
a) Change in micro-climatic conditions e.g wind spread light conditions, air range,
soil temperatures, humidity, average air temperature
b) Change in hydrological cycle. i.e circulation of water between the atmosphere, the
land and water bodies resulting in
◦ Increase soil wetness and saturation
◦ Increase surface run-off
◦ Flooding/erosion
c) Desertification
 Change soil type-deforestation-fire-farming type
 Change in biomass – lead to growth of fire resistant ssp
 Change in ecosystem
 Change soil type and nutrients
 Change in inorganic component on soil
Agro system – Dam, Irrigation farming, pesticides
Man-made ecosystem with dominant effection plants and animals
 Crop plants
 Change in pattern of weeds
CONDITIONS


3.
4.
5.
Competitive with Agric crops
Leading to geneloplant of herbicides
Pollution –Air, water, land
Change in hydrological cycles – decrease water availability
Evolutional change – Hybridization
ROLE OF MAN IN THE ECOSYSTEM
1. Man as the ecological dominants –Def. ecological dominant why man can exert
dominant
2. Man as tool making Animals (why need tools trait for making tools types of tools)
3. Man as robber animals (why chain –competition, non-consumptive use of
ecosystem)
4. Man as agents of evolution (hybride, nutifical ecosystem)
5. Man as gent of pollution (air, land, water)
6. Man as animal with substances population growth rate
MAN AS ECOLOGICAL DOMINANT
Definition: A plant or animal is describe as ecological dominant
◦ if it can compete more successfully than other organisms for the essentials
of life (particularly nutrition) in the same habitat or physical environment
◦ it can exert a greater influences in the habitat in which it lives on the other
associated living components
Example, plant, animal
Why man can exert ecological dominant mainly due to their anatomical and mental
characteristics
 Complete upright positive with bipedal locomotion
 Large and well developed hands and thumbs for fire metien than any other
primate mammals
 Omnivorous characteristics
 Well developed brain especially cerebrum for thinking
 Numerous strengths –tram is the most abundant singe spp of large mammals
except for other coneramels
 Man occupied the highest tropic level in the ecosystem i.e. No “predator”
Usefulness of Ecologic in Health
 Population trends and control
 Understand ecological basis of disease occurrence and control
 Man affect the environment and vise versa
 Research and hypothesis
 Man adaptation to physical environment
 Challenges for human develop (technology, medical science, socio-economic)
 Discovery and mobilization of resources
 Ecological disasters/control