Module 3 • A risk is the probability of suffering harm from a hazard that

can cause injury, disease, death, economic loss, or damage.

Sustaining Natural Resources and Environmental • Scientists often state probability in terms such as
Quality “The lifetime probability of developing lung cancer from
smoking one pack of cigarettes per day is 1 in 250.”
• Environmental hazards: Causes and Solutions. What Major Health Hazards Do We Face???
• Biological hazards: AIDS, Malaria, We Face Many Types of Hazards
• Chemical hazards: BPA, PCB, Pthalates, Mercury, We can suffer harm from three major types of hazards
• Nuclear hazards: Risk and evaluation of hazards. o Biological hazards from more than 1,400 pathogens that can
• Water footprint and virtual water, blue revolution. infect humans. A pathogen is an organism that can cause
• Water quality management and its conservation. disease in another organism.
• Solid and hazardous-types and waste management methods. Ex: bacteria, viruses, parasites, protozoa, and fungi.
o Chemical hazards from harmful chemicals in air, water, soil,
food, and human-made products
o Nuclear hazards from natural & anthropogenic sources

Biological Hazards—Diseases
The Global HIV/AIDS Epidemic
• A non transmissible disease is caused by something other than a
living organism and does not spread from one person to another. • The global spread of acquired immune deficiency syndrome
Such diseases tend to develop slowly and have multiple causes. (AIDS), caused by infection with the human
EX: cardiovascular (heart and blood vessel) diseases, most of the immunodeficiency virus (HIV), is a major global health threat.
cancers, asthma, and diabetes. • The virus itself is not deadly, but it cripples the immune
• Some Diseases Can Spread from One Person to Another. system and leaves the body vulnerable to infections such as
• An infectious disease is caused when a pathogen such as a tuberculosis (TB) and rare forms of cancer such as Kaposi’s
bacterium, virus, or parasite invades the body and multiplies in its sarcoma.
cells and tissues. • The virus is transmitted from one person to another
Ex: Tuberculosis, Flu, Malaria, • by unsafe sex, sharing of needles by drug users,
and Measles.
• From infected mothers who pass the virus on to their
Infectious Diseases are still
offspring before or during birth, and
Major Health Threats
• by exposure to infected blood.
 How does it not spread? Malaria—Death by Parasite-Carrying Mosquitoes
It does not spread through sweat, tears, urine, or saliva  Four species of protozoan parasites in the genus
Plasmodium cause malaria.
It does not spread through mosquito or bed bug bites  Malaria is caused by a parasite that is spread by
It does not spread through simple touch. the bites of certain mosquito species.
 It infects and destroys red blood cells, causing
It does not spread through sharing utensils, towels, clothing etc intense fever, chills, drenching sweats, anemia,
severe abdominal pain, headaches, vomiting,
It dies quickly outside blood. extreme weakness, and greater susceptibility to
Currently, there is no vaccine to prevent HIV infection and no cure other diseases.
 It kills an average of at least 2,700 people per
for AIDS. day.
• HIV/AIDS itself does not kill a person. It has no symptoms
• People die due to loss of immunity – which makes them prone to all
infectious diseases
Figure: Global outlook:
• There is treatment available to most of the infectious diseases like distribution of malaria.
pneumonia etc. About 40% of the world’s
population lives in areas
• Mother can be treated during pregnancy to prevents HIV in the child in which malaria is
prevalent.

What Types of Chemical Hazards Do We Face? Some Chemicals May Affect Our Immune, Nervous, and Endocrine Systems
• Some Chemicals Can Cause Cancers, Mutations, and Birth Defects. Immune toxins: Chemicals such as Arsenic, Methyl Mercury, and Dioxins can
• There are three major types of potentially toxic agents. weaken the human immune system and leave the body vulnerable to attacks
• Carcinogens are chemicals, types of radiation that can cause or promote by allergens and infectious bacteria, viruses, and protozoa.
cancer—(A disease in which malignant cells multiply uncontrollably and create
tumors that can damage the body and often lead to premature death). Neurotoxins: Effects can include behavioral
Ex: Arsenic, Benzene, Chloroform, Formaldehyde, Gamma radiation, Nickel, PCBs changes, learning disabilities, retardation,
(polychlorinated biphenyls), Radon, certain chemicals in tobacco smoke, Ultraviolet attention deficit disorder, paralysis, and
(UV) radiation, X-rays, and Vinyl chloride. death.
• Mutagens, includes chemicals or forms of radiation that cause mutations, or Ex: PCBs (polychlorinated biphenyls),
changes, in the DNA molecules found in cells, or that increase the frequency of Methyl Mercury, Arsenic, Lead, and certain
such changes. pesticides.
Ex: Nitrous acid (HNO2), formed by the digestion of nitrite (NO2–) preservatives in Potential pathways on which toxic chemicals can
foods, can cause mutations linked to increases in stomach cancer in people who move through the living and nonliving environment
consume large amounts of processed foods and wine with such preservatives.
Hormonally active agents (HAAs): Certain pesticides and other synthetic
• Teratogens are chemicals that cause harm or birth defects to a fetus or embryo. chemicals such as bisphenol A (BPA) have shapes similar to those of natural
Ex: Ethyl alcohol, Benzene, Cadmium, Formaldehyde, Lead, Mercury , PCBs, hormones. These wide variety of chemicals that mimic the actions of natural
Phthalates, Thalidomide, and Vinyl Chloride. hormones, allowing them to attach the ligand molecules of natural hormones
and disrupt the endocrine system in people and some other animals.
 Bisphenol A (BPA) Phthalates
A widely used estrogen mimic is bisphenol A (BPA).
• Phthalates are found in many perfumes, cosmetics, baby powders, body
lotions, hair sprays, deodorants, nail polishes, and shampoos for adults and
It is a chemical building block in certain hardened babies.
plastics (especially shatter-proof polycarbonate)
used in a variety of products including baby bottles • They are also found in PVC products such as soft vinyl toys, teething rings,
(Figure) and sipping cups, reusable water bottles, and blood storage bags, IV bags, and medical tubes used in hospitals.
sports drink and juice bottles etc., • High doses of various phthalates has caused birth defects and liver cancer,
There is concern that bisphenol A (BPA), an kidney and liver damage, premature breast development, immune
estrogen mimic, can leach out of polycarbonate suppression, and abnormal sexual development.
baby bottles, especially when they are warmed,
micro-waved, or used to hold acidic juices.
Consumers now have a choice, since most makers
of baby bottles, sipping cups, and sports water
bottles offer BPA-free alternatives.
Very low levels of BPA effects include brain damage, early puberty, prostrate
disease, breast cancer, heart disease, liver damage, reduced sperm count,
impaired immune function, type 2 diabetes, hyperactivity, increased
aggressiveness, impaired learning, etc.

Ways to prevent or control inputs of mercury into the environment from

Mercury’s Toxic Effects human sources
• Mercury (Hg) and its compounds are all toxic.
• Research indicates that long-term exposure to high levels of mercury can
permanently damage the human nervous system, brain function, kidneys,
and lungs.
• And fairly low levels of mercury can harm fetus and cause birth defects.
• Because mercury is an element, it cannot be broken down or degraded.
Therefore this indestructible global pollutant accumulates in soil, water,
and the bodies of people and other animals that feed high on food chains
and webs.
Humans are exposed to mercury in three ways.
1. They may inhale vaporized elemental mercury (Hg) or particles of inorganic
mercury salts such as HgS and HgCl2.
2. They may eat fish contaminated with highly toxic methylmercury (CH3Hg+).
3. High fructose corn syrup (HFCS) is widely used as a sweetener in beverages
and food products.
 Some potentially harmful chemicals found in most homes.
Nuclear Hazards

Dealing with Radioactive Wastes Produced

by Nuclear Power Is a Difficult Problem Nuclear Hazards
• Radioactive substance are present in Nature
• High-level radioactive wastes consist mainly of spent fuel rods
and assemblies from commercial nuclear power plants and • Undergo natural radioactive decay in which unstable
assorted wastes from the production of nuclear weapons. isotopes spontaneously give out fast moving
particles, high energy radiation or both, at a fixed
• They must be stored safely for at least 10,000 years and, by rate until a new isotope is formed
some estimates, up to 240,000 years if long-lived plutonium-
235 is not removed from the wastes. • Energy:
-Gama rays (High energy electromagnetic radiation)
• Ionization Particles:
-Alpha (Positively charged)
-Beta (Negatively charged)
 Sources of Radioactivity Effects of Radioactivity

• Natural sources: • Radiation affects all living organisms

- Cosmic rays, Rd-222, • Causes harmful changes in the body cells and also
- Soil, Rocks, Air, Water and Food containing in the genetic level
radioactive substances i) Genetic damage: Induces mutation in DNA-
affects genes and chromosomes.
• Anthropogenic sources: -damage is often seen in offsprings and may be
- Nuclear Power Plants transmitted upto several generations
- Nuclear accidents ii) Somatic damage: Includes burns, miscarriages,
eye cataracts and cancer for bone, thyroid,
- X-rays, diagnostic kits, test laboratories breast, lungs and skin

Chernobyl – April 26th, 1986

Radio Activity Effects… Chernobyl: the World’s Worst Nuclear Power Plant Accident
The reactor partially melted down and its graphite moderator caught fire and
• Damage is depends on the penetration power of the radiation burned for 10 days. The initial explosion and the prolonged fires released a
radioactive cloud that spread over much of Belarus, Russia, Ukraine, and Europe
• α-particles though has less penetration power but they have and eventually encircled the planet.
more energy than β- particle  Accident in nuclear power station occurred due to improper shutting of the
• Radio isotopes enter into the environment during mining of plant. Temperature rose to 2000°C, two explosions occurred
Uranium  1000 tone steel concrete lid blew off and radioactive materials sprayed over
the area Contained I 131, Cs 134 & Cs 137
• Radio isotopes enter in to humans by water (contamination of  First day 31 died, 239 were hospitalized. By 2005, 56 people had died
underground bodies) & food (Radioactivity in the earth’s crust prematurely from exposure to radiation released by the accident.
enters the crops grown there)  Later cases found: Thyroid cancer and leukemia, ulcerating skin, nausea,
anemia, Blood abnormalities
• Radioactive Iodine (I 131)- Cancer
 350,000 people had to abandon their homes because of contamination by
• Radioactive Strontium (Sr 90)— Leukemia radioactive fallout.
 WHO estimated about ~2,12,000 of long-term deaths from the accident
 Agriculture was damaged
 Flora and fauna damaged
 How Do We Perceive Risks and
Control of Nuclear Pollution How Can We Avoid the Worst of Them?

• Setting up of nuclear power plants should be carefully • The Greatest Health Risks Come from Poverty, Gender, and Lifestyle
Choices
done after studying long term/short term effects
• Cigarette smoking is the world’s most preventable major cause of
• Proper disposal of waste from laboratory involving the suffering and premature death among adults.
use of isotopes should be done • The WHO estimates that each year tobacco contributes to the
premature deaths of at least 5.4 million people & life-long smokers
reduce their life spans by an average of 15 years.
Here are some guidelines for evaluating and reducing risk
o Compare risks.
o Determine how much risk you are willing to accept.
o Determine the actual risk involved.
o Concentrate on evaluating and carefully making important
lifestyle choices

Why are water footprints important?

Water Footprint • The total ‘water footprint’ of a nation is a useful indicator of a
nation’s call on the global water resources.

• A water footprint is quite simply the volume of water used. • The water footprint of a nation is related to dietary habits of
people. High consumption of meat brings along a large water
• It is also referred to as 'embedded water’.
footprint.
• At the individual level, this is expressed in ‘liters’.
• But at the national level, this becomes complex – • Freshwater is a scarce resource; its annual availability is limited and
• The water footprint of a nation = demand is growing.
Use of domestic water resources – (virtual water export • The water footprint of humanity has exceeded sustainable levels at
flows) + (virtual water import flows). several places and is unequally distributed among people.
• The water footprint is a multidimensional indicator, not only
referring to a water volume used, but also making explicit • Good information about water footprints of communities and
where the water footprint is located, what source of water businesses will help to understand how we can achieve a more
is used, and when the water is used. sustainable and equitable use of fresh water.
 Why are water footprints important? Virtual Water
• There are many spots in the world where serious water • Virtual water is the amount of water that is embedded
depletion or pollution takes place: rivers running dry, in food or other products needed for its production.
dropping lake and groundwater levels and endangered
species because of contaminated water. • In 1993, Professor John Allan, strikingly demonstrated
this by introducing the "virtual water" concept, which
• The water footprint helps to show the link that exists between measures how water is embedded in the production and
our daily consumption of goods and the problems of water trade of food and consumer products.
depletion and pollution that exist elsewhere, in the regions
where our goods are produced. • Trade in virtual water allows water scarce countries to
import high water consuming products while exporting
• Nearly every product has a smaller or larger water footprint, low water consuming products and in this way making
which is of interest for both consumers that buy those water available for other purposes [World Water
products and businesses that produce, process, trade or sell Council].
those products in some stage of their supply chain.

Blue Revolution
• For a cup of coffee -140 liters of water used to
grow, produce, package and ship the beans. Blue Revolution is the water equivalent of
the green revolution
• It is roughly the same amount of water used
by an average person daily in England for It primarily refers to the management of
water resources that can steer humanity to
drinking and household need. achieve drinking water and crop irrigation
security.
• Per capita, Americans consume around 6,800
In the Third World Water Forum in Tokyo, the
liters of virtual water every day, over triple UN estimated that 2.7 billion people will face
that of a Chinese person. a critical shortage of drinkable water by
2025 and hence, solutions are desperately
needed.
 Blue Revolution Blue Revolution
• Blue Revolution movement aimed at increasing drastically the • Blue Revolution (Aquaculture) : Refers to all forms of active
global food production using aquaculture culturing of aquatic animals and plants, occurring in marine,
• Intense growth is observed in the worldwide aquaculture brackish or freshwaters.
industry from the mid-1960s to present.  An attempt to protect marine life and to
ensure sufficient seafood for the present and
• The aquaculture industry has been growing at an average rate
future generation
of nine-percent a year.  Encourage fish farming
• Worldwide aquaculture production has now reached 50  Significant increase in the amount of fish
million tons, up from two million in 1950. available
 Prices of fish have fallen
• A similar growth in land-based agriculture observed in the
1960s and 1970s is commonly referred to as the green • Most aquaculture production occurs in Asia, although there is
revolution. also a growing industry in North American.
• The Blue revolution in India was started in early 1970s during
fifth 5 year plan when Indian government sponsored the Fish
Farmers Development Agency FFDA.

Water quality / Water pollutants

Blue Revolution
• Blue Revolution experts will evaluate and recommend a best
practice for water conservation.
• Many sources of vegetation only need minimal amounts of
water to survive.
• Homes with access to alternative sources of irrigation water
can reduce their water usage significantly.
• Water that comes from your bath, dishwasher, laundry, and
any sink without a garbage-disposal can be used for
landscape irrigation.
• Nutrients in greywater will fertilize landscaping naturally
and maintain a healthy yard without the manual spreading
of fertilizer.
 Water quality management Water quality management
• Wastewater treatment systems Treatment of sewage
• Done in three stages
• Convert human and industrial liquid wastes and • Primary, secondary and tertiary
make them safe enough (from the public health
perspective) to return to the aquatic or terrestrial
environment.
• VIT has waste water treatment plant – our gardens
are grown with it
• Wastewater treatment systems use the same
processes of purification that would occur in a
natural aquatic system only they do it faster and in a
controlled situation.

Treatment of sewage - Primary

Treatment of sewage – Secondary stage
• Done for Removal of large objects using grates and screens
• flocculating chemicals are added to enhance sedimentation • Involves biological treatment
– Aerobic
– Anaerobic
– Facultative (combined)
 Treatment of sewage – Tertiary stage
• Done to improve the quality further

Water Conservation
How Can We Use Water More Sustainably?
• Reducing Water Waste is quicker and
cost-effective option rather than
trying to provide new supplies of
water.

• Use proper irrigation techniques. We

Can use Water Waste in Irrigation

• We Can Recycle Water Waste in

Industry and Homes

• We Can Redesign manufacturing

processes to use Less Water

• Use water meters

• Use waterless composting toilets and

bio-toilets (used in Indian Railways)
 Solid waste
Solid Waste Management A solid waste can be either a solid or a semi solid
discarded material.
It is classified on the basis of
• Its nature –
– chemical waste, metallic waste, e-waste,
– Hazardous and Non-Hazardous
– Biodegradable – Non-biodegradable
• From the source: Domestic waste, Industrial waste,
Hospital/Biomedical waste, Agricultural waste, Construction
waste
• Urban/Municipal waste

Hazardous and Non-hazardous waste

Sources of urban and industrial waste
Hazardous Waste is a "solid waste" which because of its quantity,
concentration, or physical, chemical, or infectious characteristics may • Domestic waste : Polyethene bags, glass bottles, waste paper,
pose a substantial present or potential hazard to human health or the aluminium cans, cloth, food waste
environment when improperly treated, stored or disposed of, or
otherwise mismanaged • Waste from shops: Paper, packing materials, cans, bottles, scrap
metal, tea leaves
• Hazardous waste is any waste that causes harm to life • Biomedical waste: Anatomical wastes, pathological wastes,
– Eg., Thermometers, infectious wastes
– Batteries, • Construction and demolition wastes: Bricks, rubbles
– Nuclear waste,
• Horticultural wastes and wastes from slaughter houses: Vegetable
– Computers, circuit boards and monitors, - other electronics parts, dried plants, remains of slaughtered animals
– Vacuum pump oil, lubricants… ……………………….
• Nuclear wastes from research laboratories, power plants
• Non-Hazardous solid waste -it does not give rise to hazardous products upon
treatment, storage or disposal. SOME OF THEM ARE VERY DANGEROUS IF YOU THROW THEM OUT DIRECTLY…
• Eg: Domestic wastes like animal and vegetable wastes, metal scrap, empty
cartons, paper,
Industrial waste (after treatment and waste from water treatment plant)
 Effects of solid wastes Effects of solid wastes
• Muncipal solid wastes pile up • In poor countries, many people make their livelihood on
– Biodegradable materials waste. They are prone to lot of diseases
decomposing under
uncontrolled conditions
increases pathogens
– Non biodegradable
materials accumulate
• Industrial solid wastes
contain toxic chemicals and
hazardous wastes – cause
land degradation and may
spread to food chain
• When all of them are burnt
together they may produce
dioxins, furans and
polychorinated biphenyls
(PCBs) which are highly toxic

Effects of solid wastes How solid waste affected us in recent years?

• Stray animals are dying on streets and farmlands due to consumption
of plastic bags, which blocks the food movement in their stomach  Recent Floods - Chennai
(2015), Hyderabad (2020) is
• Cause damage to ecosystem.
caused due to improper
• Plastic use is banned in Tamil Nadu design and maintenance of
drainage systems

 Blast in the Bhusan Steel

factory at Noida, caused due
to imported scrap from Iran

 Reduction in the number of

migratory birds due to
consumption of contaminated
foods
 Problems in Dealing With Solid Waste
Solid Waste in India
• Education & voluntary compliance
• 7.2 million tones of hazardous waste
• Collection of waste/ Refuse mixing:
• One Sq km of additional landfill area every-year • Mixing of hazardous and non-hazardous substances – makes disposal
a problem
• Rs 1600 cr. for treatment & disposal of these wastes
Eg: cans, pesticides, batteries etc are mixed with animal and plant
wastes in domestic wastes
• In addition to this industries discharge about 150 million
tones of high volume low hazard waste every year, which is • Technological interventions
mostly dumped on open low lying land areas.
• Institutions & regulatory framework
• Absence of mandatory standards for waste reduction
Source: Estimate of Ministry of Environment & Forest
• Market action for waste reduction

Management of Solid Waste

Management Methods
Municipal (Urban)
Solid Waste Management Solid Waste Management methods are: ‘3R’s.
• Reduction (avoid)
(MSW Management) • Reuse
• Recycle
& Dispose, Treatment (Safe storage)
Municipal Solid Waste (MSW) and its management Municipal Solid Waste (MSW) and its
management
1. Reduce/Avoid :
• Reduction in the use of non-biodegradable 2. Reuse:
materials will reduce the waste • The materials discarded by one are used by
• This has to be done individually. another in the same form
• Never buy anything unnecessarily. • In poor countries reuse is very common
– Eg: Reduction in use of metallic products • Eg: Clothes,
reduces the mining • Used furniture
• Used vehicles

Managing Waste Managing Waste – recycling contd.

3. Recycling: (Not same Benefits of recycling:

as reusing!) • Reduce environmental degradation
Processing of a waste item into • Making money out of waste,
another usable forms.
• Eg. Converting kitchen waste to
• Reduce the cost and need of raw materials –
fuel pellets, saves natural resources
• Melting and reusing aluminum • Save energy that would have gone into waste
cans etc handling & product manufacture
• Making decoratives from • Examples for Saving through recycling:
wastes • When Al is resembled- considerable saving in cost
• Revulcanize vehicle tires and • Making paper from waste saves 50% energy
use as a binder for road • Every tone of recycled glass saves energy equivalent to
construction 100 liters of oil
 Recycling not a solution to all problems! Waste disposal:
Discarding wastes
Recycling is not a solution to managing every
kind of waste material Done only when the 3Rs cannot be applied.
Process involves the following stages
• Physical removal: Manually collecting wastes
For many items recycling technologies are • Dumping: Transfer of solid waste from place of collection
unavailable or unsafe to the site of disposal
• Compaction and bailing:
– Pressing with bulldozers is compaction
In some cases, cost of recycling is too high. – Rolling the compressed waste is bailing
• Using for Landfill or incineration

Waste disposal – Waste Disposal…

1. Sanitary Landfill 2. Composting:
• In sanitary landfill waste is spread out, compacted and covered with
layers of clay, sand or gravel or plastic foam • Bio degradable waste is allowed to decompose in an
• The bottom is covered before landfill to prevent leaching of ground oxygen rich medium
water • A good quality nutrient rich manure is formed, which
• Several wells are dug nearby to monitor leakage from ground water improves the soil conditions & fertility
contamination
• Methane gas if formed, is collected and used as a fuel or for electric
heating.
 Waste Disposal –
Materials for Composting
Acceptable Not Acceptable
3. Incineration
• Grass clippings • Meats • Incinerators are burning plants capable of burning a large
• Leaves and Weeds • Bones amount of materials at high temperature.
• Coffee and tea Grounds • Synthetic Products • Burning of waste materials that are combustible under
• Wood Chips, Sawdust • Plastics controlled conditions.
• Bark, Stems, Stalks • Pet or Human Solid
Wastes • Initial cost of setting up of the plant is high
• Garden & Canning Waste
like weeds • Oils and fats • Remove batteries containing heavy metals and plastic
• Peels and scrap from Fruit • Diseased plant containing chlorine before burning the material
& Vegetables products
• Egg shells – Prior removal of plastics will reduce emissions of dioxins and
• Wool and cotton rags polychlorinated biphenyls
• Non recyclable paper • Advantages are:
– substantial reduction in waste volume

– Although initial set up cost is high, later becomes self sustainable

– Removes pathogenic organisms when medical waste is incinerated

Solid Waste Management - Hierarchy

Composting
 Waste control measures – 3R s

• Use less of raw materials

• Use high quality materials so that less by-
products or waste and less toxins
• Process waste
• Reuse waste
• Recycle waste
• Create strategic planning – implement and
monitor