Development and Environment Unit-I

1. Safety Health and Environmental
Engineering
Development and Environment
Unit-I

2. Syllabus
Development and Environment:
• Global and regional environmental issues,
issues of land, water, air and noise pollution

3. Global Environmental Issues

4. Green House Effect
• The Increase in CO2 content of the
environment has been responsible for gradual
heating up the globe, by a process called as
green house effect. The progressive warming
up of the earth’s surface due to blanketing
effect of manmade CO2 in the atmosphere is
known as green house effect.

5. Green House Effect

6. • From sun 3 types of radiations are emitted,
ultraviolet rays(< 400 nm), Visible rays ( 400 –
700 nm) and Infrared rays (700 – 1000 nm), of
this the visible rays are having maximum
intensity i.e. (400 nm to 700nm wavelength).
Approx 47 % of the solar radiation is absorbed by
water and land surfaces and the remaining rays
are radiated back to the atmosphere in the form of
Infrared rays (700 nm – 1000 nm). Water vapor
and CO2 molecules in atmosphere near earth’s
surface absorb the infrared radiations (heat rays)
emitted by earth. Thus the net effect causes
warming of atmosphere. This effect is called a
green house effect.

7. Principle of Green House Effect
• The transparent walls and roofs of the green house are such that
they allow visible sunlight to enter but prevents the entry of long
wavelength Infrared radiations to go out.
• Thus the sunlight is absorbed by soil and structure of the green
house. It is then re-emitted as heat rays which cannot pass
through the glass. The amount of energy in the green house thus
increases the warmth of the atmosphere. In similar ways the
earth’s atmosphere bottles up the energy of the sun like green
house. Here CO2 and water vapor acts like glass windows.
• CO2 and water vapor in the atmosphere transmits short
wavelength solar radiations but reflect longer wavelength heat
radiations from warm surfaces of the earth. CO2 molecules are
transparent to sunlight but not to heat radiations, so they trap and
re-enforce the solar heat like a green house

8. Green House

10. Green House Gases
•
•
•
•
•
Carbon dioxide ( CO2)
Methane ( CH4)
Nitrous oxide ( N2O)
Chlorofluorocarbon (CFC)
Ozone

11. Sources of Green House Gasses
• Burning of Coal, Oil, Natural Gas in the factories.
• Burning of fossil fuels at power stations
• Use of Petrol and Diesel from automobiles,
railways, aircrafts etc.
• Burning of firewood and deforestation
• Tree and plants release carbon as CO2.
• Fire in the forests contribute to the release of CO2

12. Effects of Warming up of Air
• Increase in temperature on earth’s surface will
cause more evaporation of surface water.
• Melting of Glaciers (ice mountains)
• Rise in Sea Level will wash away entire
countries from Bombay to Boston.
• Shifting of climate zones will occur.

13. CO2, CH4, N2O, CFC’s, O3, H2O
Vapor

14. Control
• Reduce the consumption of fossil fuels
• Use anti pollution devices
• Non conventional energy sources should be
developed as a alternate to fossil fuel.
• Prevent deforestation
• Planting more trees.

15. Acid Rain
• Acid
Rain
is
a
environmental
Problem
caused due to rapid
industrialization. Acid rain
has become invisible threat
to rivers, lakes and forests.
• Acid rain means presence
of acids in rainwater. The
basic component of acid
rain are nitric acid, and
sulphuric acid.

16. Causes of Acid Rain
• Acid Rain is because of human activities.
Sulphuric acid is formed when (SO2) is
discharged from combustion process converts
to sulphurtrioxide (SO3) which reacts with the
water vapor present in the atmosphere to form
sulphuric acid (H2SO4).
The oxides of sulphur and nitrogen are produced
by combination of fossil fuels, smelters, power
plant, automobile exhausts, domestic fire.

18. Acid Rain Formation

19. Effects of Acid Rain
• The acid rain damages the leaves of plants and trees
and retard the growth of forest.
• Wash out the nutrients from the soil.
• Significant reduction of fish population and decease in
aquatic micro organisms.
• Damage to Buildings and structural materials.
• Corrosion of houses, monuments, statues and bridges.
• The human nervous system, respiratory system and
digestive system may get affected
• Acid rain reduces the rate of photosynthesis and hence
growth of plants.

20. Effects of Acid Rain

21. Control
• Liming of Lakes
• Tough laws to reduce acid forming pollutants,
being released in atmosphere.

22. Ozone Layer Depletion
• Ozone layer depletion is mainly
due to Chloro-floro carbons
(CFC). Ozone layer prevents the
harmful ultraviolet rays from
entering in the atmosphere but
(CFC) is one of the main ozone
eaters and it allows the
penetration of harmful ultraviolet
rays.
Chloro-floro
carbon
remains in the atmosphere for
decades and reacts with the
atmospheric
chlorine
to
accelerate the long chain
reaction. This chain reaction
slowly eats away the oxygen
atom which could be used in the
formation of ozone.
© NOAA

23. • Thus it leads to decrease in Ozone
concentration which results in reaching of
ultraviolet rays to earth surface due to which
heat increases to uncomfortable levels and the
temperature of earth increases.

24. Main Ozone layer Depletors
• CFC (Chloro Floro Carbon) The Chlorofloro
carbon are less costly, non toxic, and safe to
handle material is used in propellants, cleaning
solvents, plastic foams, in dry cleaning
industries, for sterilizing surgical instruments.
Because of wide use of CFC the CFC in the
atmosphere is increased and which has caused
irreparable damage to our environment.

25. • Oxides of Nitrogen:- Burning of Fossil fuels
and increase in use of nitrogen as a fertilizer
are also contributing in destruction of ozone
layer.
• Thus in addition to CFC, the oxides of
nitrogen also plays an important role in
depletion of Ozone.

26. Mechanism of Ozone Depletion
• The chlorofloro carbons are highly stable and
hence they slowly diffuse in the atmosphere.
The ultraviolet rays decompose the CFCs and
thus free chlorine and fluorine radicals are
released In the atmosphere. This chlorine
radical released in the atmosphere converts O3
into O2
• Similarly oxides of Nitrogen also depletes the
ozone

27. • CFCl3
UV rays
• Cl + O3
UV rays
• ClO + O
UV rays
CFCL2 + Cl
ClO + O2
Cl + O2
• Similarly UV rays
• NOx + O3
NO2 + O2

29. Oxygen in the
+
O2
Atmosphere
UV
radiation
O
+
O
O
+
O2
O3 (ozone)

30. +
O3
(ozone)
+O3
(ozone)
UV
O
O
O
+
O2
+
O2
O2
O3
+
O2
+
(ozone)
heat

31. Cl- “Free Radicals”…
Cl-
+
O3
(ozone)
“free radical”
+
ClO
O
+
ClO
O2
+
Cl“free radical”
O2

32. Effects of Ozone Depletion
• The damage to ozone layer will result in
damage to plants and animals
• For every 2.5 cm increase in the size of ozone
hole, there will be 5 – 6 % increase in skin
cancer and cataracts.
• Ultraviolet
rays
may
interfere
with
photosynthesis leading to lower crop yield
• Ultraviolet rays causes genetic changes in
DNA, leading to lower crop yield.

33. Control.
• Discourage use of CFCs and NOx
• Better alternative for CFC should
developed.
• Reforestation and forest prevention.
be

34. 28.0 million km2 on 25 September 2006
© NASA

35. Maximum ozone hole area for 2009
was 24 million km2 on 17 September.
The Dobson unit (DU) is a unit of measurement of atmospheric ozone columnar density,
specifically ozone in the stratospheric ozone layer. One Dobson unit refers to a layer of
ozone that would be 10 µm (micrometre)

36. 08 January 2014
Good news for fans of planet Earth: hole in the ozone
layer may be healing. .

37. Regional Environmental Issues

38. Urban Heat Island

39. Urban Heat Island

40. Urban Heat Island
• An urban heat island (UHI) is a metropolitan
area that is significantly warmer than its
surrounding rural areas due to human
activities.
• The temperature difference usually is larger at
night than during the day, and is most apparent
when winds are weak.
• UHI
is
most
noticeable
during
the summer and winter. The main cause of the
urban heat island effect is from the
modification of land surfaces,

41. Urban Heat Island

42. Urban Heat Island
• Monthly rainfall is greater downwind of cities,
partially due to the UHI. Increases in heat
within urban centres increases the length of
growing seasons, and decreases the occurrence
of weak tornadoes.
• The UHI decreases air quality by increasing
the production of pollutants such as ozone, and
decreases water quality as warmer waters flow
into area streams and put stress on
their ecosystems.

43. Urban Heat Island

44. Urban Heat Island
• Not all cities have a distinct urban heat island.
Mitigation of the urban heat island effect can
be accomplished through the use of green
roofs and the use of lighter-colored surfaces in
urban areas, which reflect more sunlight and
absorb less heat.

45. Green Roofs

46. Urban Heat Island
Causes
• There are several causes of an urban heat island
(UHI). The principal reason for the night time
warming is that the short-wave radiation is still
within the concrete, asphalt, and buildings that
was absorbed during the day, unlike suburban and
rural areas. This energy is then slowly released
during the night as long-wave radiation, making
cooling a slow process.

47. Urban Heat Island
• Two other reasons are changes in the thermal properties of
surface materials and lack of evapotranspiration (for
example through lack of vegetation) in urban areas.
• With a decreased amount of vegetation, cities also lose the
shade and cooling effect of trees, Materials commonly used
in urban areas for pavement and roofs, such as concrete and
, have significantly different thermal bulk properties
(including heat capacity and thermal conductivity) and
surface radioactive properties than the surrounding rural
areas.
• This causes a change in the energy balance of the urban
area, often leading to higher temperatures than surrounding
rural areas.

48. Urban Heat Island
• Other causes of a UHI are due to geometric
effects. The tall buildings within many urban
areas provide multiple surfaces for the
reflection and absorption of sunlight,
increasing the efficiency with which urban
areas are heated. This is called the "urban
canyon effect".

49. Urban Heat Island

50. Urban Heat Island
• Another effect of buildings is the blocking of
wind,
which
also
inhibits
cooling
by convection and pollution from dissipating.
• Waste heat from automobiles, air conditioning,
industry, and other sources also contributes to the
UHI. High levels of pollution in urban areas can
also increase the UHI, as many forms of pollution
change the radioactive properties of the
atmosphere.
• As UHI raises the temperature of cities, it will
also increase the concentration of ozone in the air,
which is a greenhouse gas.

51. Urban Heat Island
Mitigation
The temperature difference between urban areas
and the surrounding suburban or rural areas can
be as much as 5 C (9 F). Nearly 40 percent of
that increase is due to the prevalence of dark
roofs, with the remainder coming from darkcolored pavement and the declining presence of
vegetation.
The heat island effect can be counteracted slightly
by using white or reflective materials to build
houses, roofs, pavements, and roads, thus
increasing the overall albedo of the city.

52. Urban Heat Island

53. Urban Heat Island
• Relative to remedying the other sources of the
problem, replacing dark roofing requires the
least amount of investment for the most
immediate return. A cool roof made from a
reflective material such as vinyl reflects at
least 75 percent of the sun’s rays, and emit at
least 70 percent of the solar radiation absorbed
by the building envelope. Asphalt built-up
roofs (BUR), by comparison, reflect 6 percent
to 26 percent of solar radiation.

54. Urban Heat Island

55. Urban Heat Island
• Using light-colored concrete has proven effective in
reflecting up to 50% more light than asphalt and
reducing ambient temperature.
• Paving with light-colored concrete, in addition to
replacing asphalt with light-colored concrete,
communities may be able to lower average
temperatures.
• However, research into the interaction between
reflective pavements and buildings has found that,
unless the nearby buildings are fitted with reflective
glass, solar radiation reflected off light-colored
pavements can increase building temperatures,
increasing air conditioning demands.

56. Light Colored Concrete

57. Urban Heat Island
• A second option is to increase the amount of wellwatered vegetation. These two options can be
combined with the implementation of green roofs.
Green roofs are excellent insulators during the
warm weather months and the plants cool the
surrounding environment.
• Air quality is improved as the plants absorb and
convert carbon dioxide to oxygen.
• From the standpoint of cost effectiveness, light
surfaces, light roofs, and curb side planting have
lower costs per temperature reduction

58. Urban Heat Island

59. Urban Heat Island

60. Light Pollution
• Light pollution, also known as photo
pollution or luminous pollution, is excessive,
misdirected,
or
obtrusive
artificial
light. Pollution is the adding-of/added light itself,
in analogy to added sound, carbon dioxide, etc.
Adverse consequences are multiple; some of them
may not be known yet. Scientific definitions thus
include the following:
• Degradation of photic habitat by artificial light.

61. Light Pollution
• Alteration of natural light levels in the outdoor
environment owing to artificial light sources.
• Light pollution is the alteration of light levels in
the outdoor environment (from those present
naturally) due to man-made sources of light.
Indoor light pollution is such alteration of light
levels in the indoor environment due to sources of
light, which compromises human health.
• Light pollution is the introduction by humans,
directly or indirectly, of artificial light into the
environment.

62. Light Pollution

63. Light Pollution
• Light pollution competes with starlight in the night
sky
for
urban
residents,
interferes
with astronomical observatories, and, like any other
form of pollution, disrupts ecosystems and has adverse
health effects. Light pollution can be divided into two
main types:
• Unpleasant light that intrudes on an otherwise natural
or low-light setting
• Excessive light (generally indoors) that leads to
discomfort and adverse health effects
• Light pollution is a side effect of industrial civilization.
Its sources include building exterior and interior
lighting, advertising, commercial properties, offices,
factories, streetlights, and illuminated sporting venues

64. Light Pollution

65. Light Pollution
Measurement and global effects
• False colors show various intensities of radiation,
both direct and indirect, from artificial light
sources that reach space
• Measuring the effect of sky glow on a global scale
is a complex procedure. The natural atmosphere is
not completely dark, even in the absence of
terrestrial sources of light and illumination from
the Moon. This is caused by two main
sources: airglow and scattered light.

66. Light Pollution

67. Light Pollution
• At
high
altitudes,
primarily
above
the mesosphere, there is enough UV radiation
from the sun of very short wavelength that
ionization occurs. When these ions collide
with electrically neutral particles they
recombine and emit photons in the process,
causing airglow.

68. Light Pollution

69. Effects on animal and human health and
psychology
Effects on animal and human health and
psychology
• Medical research on the effects of excessive light on the
human body suggests that a variety of adverse health
effects may be caused by light pollution or excessive light
exposure,
• Health effects of over-illumination or improper spectral
composition of light may include: increased headache
incidence,
worker
fatigue,
medically
defined
stress, Likewise, animal models have been studied
demonstrating unavoidable light to produce adverse effect
on mood and anxiety. For those who need to be awake at
night, light at night also has an acute effect on alertness
and mood

70. Effects on animal and human health
and psychology

71. Effects on animal and human health
and psychology

72. Disruption of ecosystems
• When artificial light affects organisms and ecosystems
it is called ecological light pollution. While light at
night can be beneficial, neutral, or damaging for
individual species, its presence invariably disturbs
ecosystems.
• Light pollution poses a serious threat in particular
to nocturnal wildlife, having negative impacts on plant
and animal physiology. It can confuse animal
navigation, alter competitive interactions, change
predator-prey relations, and cause physiological
harm. The rhythm of life is orchestrated by the natural
diurnal patterns of light and dark, so disruption to these
patterns impacts the ecological dynamics

73. Disruption of Ecosystems

74. Reduction
Reduction
• This kind of LED droplight could reduce unnecessary
light pollution in building interiors
• Reducing light pollution implies many things, such as
reducing sky glow, reducing glare, reducing light
trespass, and reducing clutter. The method for best
reducing light pollution, therefore, depends on
exactly what the problem is in any given instance.
Possible solutions include:

75. Reduction
• Utilizing light sources of minimum intensity
necessary to accomplish the light's purpose.
• Turning lights off using a timer or occupancy
sensor or manually when not needed.
• Improving lighting fixtures, so that they direct
their light more accurately towards where it is
needed, and with less side effects.

76. Reduction

77. Reduction
• Adjusting the type of lights used, so that the light waves
emitted are those that are less likely to cause severe
light pollution problems. Mercury, metal halide and
above all first generation of blue-light LED road
luminaries are much more pollutant than sodium lamps:
Earth atmosphere scatters and transmits blue light
better than yellow or red light. It is a common
experience observing "glare" and "fog" around and
below LED road luminaries as soon as air humidity
increases, while orange sodium lamp luminaries are
less prone to show this phenomenon.
• Evaluating existing lighting plans, and re-designing
some or all of the plans depending on whether existing
light is actually needed.

78. Reduction

79. Arsenic Poisoning
Arsenic Poisoning
Arsenic poisoning is a global problem arising from
naturally occurring arsenic in ground water.
Arsenic poisoning is a medical condition caused by
elevated levels of arsenic in the body. The dominant
basis of arsenic poisoning is from ground water that
naturally contains high concentrations of arsenic. A
2007 study found that over 137 million people in more
than 70 countries are probably affected by arsenic
poisoning
from
drinking
water

80. Arsenic Poisoning

81. Symptoms
• Symptoms of arsenic poisoning begin with headaches,
confusion, severe diarrhoea, and drowsiness. As the
poisoning develops, convulsions and changes in
fingernail pigmentation called leukonychia striata may
occur.
• When the poisoning becomes acute, symptoms may
include diarrhoea, vomiting, blood in the urine,
cramping muscles, hair loss, stomach pain, and more
convulsions. The organs of the body that are usually
affected by arsenic poisoning are the lungs, skin,
kidneys, and liver. The final result of arsenic poisoning
is coma and death

82. Arsenic Poisoning

83. leukonychia striata

84. Arsenic Poisoning

85. Arsenic Poisoning
• Arsenic is related to heart disease(hypertension
related
cardiovascular),
cancer, stroke (cerebrovascular diseases),
chronic
lower
respiratory
diseases, and diabetes
• Chronic exposure to arsenic is related
to vitamin A deficiency which is related to
heart disease and night blindness

86. Drinking Water
• Chronic arsenic poisoning results from
drinking contaminated well water over a long
period of time. Many aquifers contain high
concentration of arsenic salts. The World
Health Organization recommends a limit of
0.01 mg/L (10ppb) of arsenic in drinking
water. This recommendation was established
based on the limit of detection of available
testing equipment at the time of publication of
the WHO water quality guidelines.

87. Drinking Water
• More recent findings show that consumption of water
with levels as low as 0.00017 mg/L (0.17ppb) over long
periods of time can lead to arsenicosis. The World
Health Organization asserts that a level of 0.01 mg/L
poses a risk of 6 in 10000 chance of lifetime skin
cancer risk and contends that this level of risk is
acceptable.
• One of the worst incidents of arsenic poisoning via well
water occurred in Bangladesh, which the World Health
Organization called the "largest mass poisoning of a
population in history.

88. Removal Methods
Removal Methods
• Various techniques have been evolved for
Arsenic removal, most frequently using
absorbents such as activated carbon,
aluminium oxide, co-operative with iron oxide
to form sludge’s, sorption onto iron-oxidecoated
polymeric
materials,
Electro
coagulation, by nanoparticle .

89. Removal Methods

90. Fluoride in Groundwater
• Groundwater is the major source for various
purposes in most parts of the world. Presence
of low or high concentration of certain ions is
a major issue as they make the groundwater
unsuitable for various purposes.

91. Fluoride in Groundwater

92. Fluoride in Groundwater
• Fluoride is one such ion that causes health
problems in people living in more than 25
nations
around
the
world.
Fluoride
concentration of at least 0.6 mg/l is required
for human consumption as it will help to have
stronger teeth and bones. Consumption of
water with fluoride concentration above 1.5
mg/l results in acute to chronic dental fluorosis
where the tooth become coloured from yellow
to brown.

93. Fluoride in Groundwater

94. Fluoride in Groundwater
• Skeletal fluorosis which causes weakness and
bending of the bones also results due to long
term consumption of water containing high
fluoride. Presence of low or high concentration
of fluoride in groundwater is because of
natural or anthropogenic causes or a
combination of both

95. Dental Fluorosis

96. Skeletal Fluorosis

97. Occurrence of fluoride
Aquifer material
• Most of the fluoride in groundwater is
naturally present due to weathering of rocks
rich in fluoride. Water with high concentration
of fluoride is mostly found in sediments of
marine origin and at the foot of mountainous
areas

98. Occurrence of fluoride

99. Volcanic ash
• Volcanic rocks are often enriched in fluoride.
Hydrogen fluorine is one of the most soluble
gases in magmas and comes out partially during
eruptive activity The aerial emission of fluoride in
the form of volcanic ash during volcanic eruption
reaches the surface by fall out of particulate
fluorides and during rainfall. This fluoride from
the soil surface will easily reach the groundwater
zone along with percolating rainwater.

100. Volcanic ash

101. Fertilisers
Fertilisers
• Phosphate containing fertilisers add up to the
fluoride content in soil and groundwater It is
evident that superphosphate, potash and NPK
(Nitrogen Phosphorous Potassium) which are
phosphatic fertilisers contain remarkable
amount of fluoride

102. Fertilisers

103. Health Implications
• Health Implications
• Intake of fluoride higher than the optimum
level is the main reason for dental and skeletal
fluorosis. Depending upon the dosage and the
period of exposure fluorosis may be acute to
chronic.

104. Health Implications

105. Health Implications
• when fluoride concentration in drinking water is
below 0.5 mg/l it causes dental carries; fluoride
between 0.5 to 1.5 mg/l results in optimum dental
health; 1.5 to 4 mg/l causes dental fluorosis; 4 to
10 mg/l induces dental and skeletal fluorosis
while fluoride above 10 mg/l results in crippling
fluorosis. However, fluorosis results not only due
to the presence of high concentration fluoride in
drinking water but also depend on other sources
such as the dietary habits which enhance the
incidence of fluorosis.

106. Health Implications

107. Other effects
• Other health disorders that occur due to
consumption of high fluoride in drinking water to
be muscle fibre degeneration, low haemoglobin
levels, deformities in RBCs, excessive thirst,
headache, skin rashes, nervousness, neurological
manifestations,
depression,
gastrointestinal
problems, urinary tract malfunctioning, nausea,
abdominal pain, tingling sensation in fingers and
toes, reduced immunity, etc

108. Health Implications

109. Fluoride in India
India
• Of the 85 million tons of fluoride deposits on
the earth’s crust, 12 million are found in India
.Hence it is natural that fluoride contamination
is widespread, intensive and alarming in India.

110. Fluoride in India

111. Mitigation Measures
Mitigation Measures
• Everybody needs clean water. When high
fluoride in the drinking water source has been
identified, it is better to avoid that source and
look for other sources

112. Mitigation Measures
Insitu-treatment methods
• Insitu method aims at directly diluting the
concentration of fluoride (in groundwater) in
the aquifer. This can be achieved by artificial
recharge. Construction of check dams in, India
has helped widely to reduce fluoride
concentration in groundwater

113. Insitu-treatment methods

114. Mitigation Measures
Exsitu-treatment methods
• Numerous exsitu methods are available for
defluoridation of water either at household or
community level. Adsorption method involves
the passage of water through a contact bed
where fluoride is adsorbed on the matrix.
Activated charcoal and activated alumina are
the widely used adsorbents.

115. Exsitu-treatment methods

116. Mitigation Measures
• In ion exchange process, when water passes through a
column containing ion exchange resin, the fluoride ions
replace calcium ions in the resin.
• Membrane processes is also an ex-situ technique which
includes methods called reverse osmosis and electro
dialysis. These are advanced techniques which require
high cost input
• All these methods have their own advantages and
disadvantages. Hence it is necessary to evaluate the
prevailing local conditions and cost effectiveness
before choosing a particular defluoridation method for
an area.

117. Mitigation Measures

118. Thanks …