environmental engineering (bfc32403) bfc...
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Human Impact Towards the
Environment
ENVIRONMENTAL ENGINEERING
(BFC32403)
BFC 3103
Major Global Meetings Issues
1972 Stockholm United Nations
Conference on the Human Environment
Pollution, rates of depletion of non
renewable fossil fuels and population
growth
1987 World Commission on Environment
and Development (WCED), Brundtland
report: Our Common Future
1987 Montreal Protocol
Idea of sustainable development
Substances that deplete the ozone layer
1992 Rio Summit in Brazil (Earth Summit):
Agenda 21
Ozone depletion, tropical deforestation,
loss of biodiversity, and global warming
1997 Kyoto Protocol Controlling the emissions of greenhouse
gases
2001 Johannesburg Earth Summit Energy, freshwater, food security and
health
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HISTORICAL BACKGROUND TO THE EMERGENCE
OF ENVIRONMENTAL CONCERNS
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ENVIRONMENTAL ISSUES
SOILS
FOREST SOLID & HAZARDOUS WASTE
AIR
SEA
WATER
Ozone depletion
Loss of
biodiversity
Population increase
Economic growth
Global warming
Air ,water & land
pollution
Resource depletion
Global change includes natural and human- induced changes in the Earth's environment .
Global change can be defined as changes in the global environment (including alterations in climate, land productivity, oceans or other water resources, atmospheric chemistry, and ecological systems) that may alter the capacity of the Earth to sustain life.
Population growth is the
central cause of the environmental crisis.
It also depends on the nature and degree of industrialization.
The world’s population presently grows by about 250,000 people per day.
Latest official current world population estimate, for mid-year 2011, is estimated at 6,928,198,253.
Year Population
1 200 million
1000 275 million
1500 450 million
1650 500 million
1750 700 million
1804 1 billion
1850 1.2 billion
1900 1.6 billion
1927 2 billion
1950 2.55 billion
1955 2.8 billion
1960 3 billion
1960 3 billion
1965 3.3 billion
1970 3.7 billion
1975 4 billion
1980 4.5 billion
1985 4.85 billion
1990 5.3 billion
1995 5.7 billion
1999 6 billion
2006 6.5 billion
2009 6.8 billion
2011 7 billion
2025 8 billion
2043 9 billion
2083 10 billion
Resource depletion
Resource degradation
Pollution
Loss of biodiversity
People are exposed to harmful Pollutants in the air they breathe , the liquids they drink, the food they eat, the surface they touch, and the products they use.
When the environment can not process the load
of pollutants , pollution takes place .
Every environmental system has a carrying
capacity .
Visibility reduction - airborne particles
Material damage - damage to rubber goods and textiles
Agricultural damage – damages all kinds of crops
Psychological effects – psychosomatic diseases (such as stress)
Physiological and health effects – respiratory / cardiovascular diseases and lung cancer
Interfere with photosynthesis , carbohydrates production
Damage to leaf tissue, needles and fruit
Reduction in growth rate or suppression of growth
Increased susceptibility to disease, pests and adverse weather
Reduced crop yields and makes fruit smaller, lighter and less nutritions
Global warming is caused by the emission of greenhouse gases.
72% of the emitted greenhouse gases is made up of carbon dioxide (CO2).
Carbon dioxide emissions therefore are the main cause of global warming.
CO2 is caused by burning fuels. Oil, natural gas, diesel, organic-diesel, petrol, organic-petrol, ethanol.
Emissions of CO2 have been increasing at a rate of approximately 3% yearly for the past 50 years. It is released to the atmosphere where it remains for 100 to 200 years.
A warming of 2ºC corresponds to an amount of 250 parts per million (ppm) carbon dioxide concentration in environment.
GHGs
carbon dioxide Nitrous oxide
Methane
Water vapour
Halons (halocarbons)
Fire-extinguisher
Chlorofluorocarbons
(e.g. Freon)
A refrigerant
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1. Temperature extremes
2. Rise in sea level, and change in precipitation
3. Storms, coastal flooding
4. Contamination of drinking water
5. Drought
6. Food shortages due to shift in agricultural food production
7. Air pollution ( made worse by warming)
8. Asthma, bronchitis, emphysema complications
9. Strain on public health systems
10. Increased need to population migrations
11. Unable to control spread of infectious diseases
In 1980s scientists discovered a "hole" in the ozone over Antarctica.
In 1990s atmospheric scientists reported an annual loss of 40-50% of the ozone above Antarctica.
One CFC molecule can destroy 100,000 ozone molecules.
UV-B radiation from the Sun is partially
absorbed in ozone layer.
As a result, the amount of UV-B
reaching Earth’s surface is greatly
reduced.
UV-A and other solar radiation are not
strongly absorbed by the ozone layer.
Each 1% drop in ozone is thought to increase human
skin cancer rates by 4-6%.
The United Nations Environment Program predicts
a 26 percent rise in cataracts and non-melanoma
skin cancers for every 10% drop in ozone.
This translates to 1.75 million cases of cataracts and
300,000 more cases of skin cancer every year.
Sterilization of lakes and forests.
Reducing the populations of small invertebrates
and decomposers.
Reducing agricultural yields.
Causing extensive structural damage by
corroding marble, metal, and stonework.
Degrading water supplies by leaching heavy
metals from the soil.
Increasing lung cancer and colon cancer.
Over 1 billion people lack access to safe water supplies, while 2.6 billion people lack adequate sanitation.
Water-associated infectious diseases kills 3.2 million lives each year, approximately 6% of all deaths globally.
The burden of disease from inadequate water, sanitation, and hygiene totals 1.8 million deaths.
Water pollution
Industrial Effluents
Mining and Agricultural
Wastes
Agricultural pesticides,
fertilizers and herbicides
Sewage Disposal and
Domestic Wastes
Nutrient loading may lead to eutrophication .
Organic wastes cause oxygen depletion.
Industrial discharges contain heavy metals , resin pellets, organic toxins, oils, nutrients, and solids.
Discharges from power stations can also have thermal effects, and these too reduce the available oxygen.
POPs and heavy metals cause immune
suppression ,reproductive failure or acute
poisoning.
Organic pollutants deplete DO and mass fish-
kills.
Suspended particles reduce quality of drinking
water, amount of light penetration and growth
of photosynthetic plants and microorganisms.
Bacterial infections –
Typhoid, cholera,
paratyphoid fever,
Bacillary dysentery.
Viral infections
infectious jaundice ,
polio myelitis ,
Protozoal infections –
amoebic dysentery
Water related Diseases
Water – borne infections -typhoid, cholera, hepatitis
Water – washed infections
scabies , conjunctivitis, diarrhea
Water – based infections
Schistosomiasis,guinea worm
Water – related insect vectors
Yellow fever, sleeping sickness
Defective sanitation
-Hook worm
Climate change is one
of the significant
causes of biodiversity
loss
Biodiversity is a
fundamental
determinant of health
The most significant impact of climate change is likely to be warming of the oceans.
By the 2050s, surface seawater temperatures may be as much as 2.5°C higher in summer and 2.3°C higher in winter than in 2000 (Viles, 2001).