Geological Repositories -A deep geological repository is a nuclear waste repository excavated deep within a stable geologic environment. It is suited to provide a high level of long-term isolation and containment without future maintenance. In India at Tarapur and Kalpakkam, a wet storage facility of Spent Fuel is the main mode of storage.

There are three main types of sources: point sources, non-point sources, leaks and spills. Point sources: Discharge of pollutants at specific locations through pipelines or sewers into the water body. Factory effluents, sewage, underground mines, oil wells, oil tankers and agriculture are common point sources.
Non-point sources: Sources that cannot be traced to a single site of discharge like acid rain, dumping of the plastics in water bodies and agriculture chemical run off are common examples.
Leaks and Spills: This occurs mostly due to ship collision, off shore oil rigs, oil leakages and discharges into sea.

The Chipko movement resisted the destruction of forests of India in the 1970s. Sunder lal Bahuguna was the leader of this movement. People in the movement hugged the trees, and prevented felling of trees by contractors.

Substances such as chlorofluorocarbons, methyl chloroform, carbon tetrachloride, methyl bromide are found to have direct impact on depletion of ozone layer. These are categorized as ozone depleting substances.

Acid rain is a form of precipitation that contains acidic components, such as sulfuric acid or nitric acid. It damages trees, crops and harms marine animals (coral reefs) and induces corrosion.

Increase in the concentrations of greenhouse gases such as CO₂, methane, nitrous oxide, CFCs, and ozone causes greenhouse effect, warming of the earth, resulting in sea level rise, submerging of islands and sea shores of various parts of the world

(i) Transport sources - cars, buses, airplanes, trucks and trains
(ii) Stationary sources - power plants, incinerators, oil refineries, industrial facilities and factories
(iii) Area sources - agricultural - wood / stubble burning and fireplaces
(iv) Natural sources - wind-blown dust, wildfires and volcanoes.

1. Farmers need to be made aware about organic farming which does not require any kind of fertilizers and pesticides usage.
2. Crop rotation can be practiced by farmers which reduces the need for fertilizers and improves the fertility of the soil.
3. Ships and tankers that carry oil can be supervised earlier and ensured that they are not damaged in any way and through this oil will not be split in the ocean water.

Effects: UV rays may penetrate deep into the skin and can lead to premature skin aging and wrinkling of skin; suppression of the immune system, skin cancer (melanoma) and chronic effects leading to eye damage. DNA damage can result from free radicals and reactive oxygen and photons can damage the DNA itself.

Ozone hole is the area above Antarctica, where the ozone layer is the thinnest.

(a) Eutrophication:
1. Eutrophication is defined as the process of nutrient enrichment of water and consequent loss of species diversity in water bodies.
2. Increased nutrient content of the water body causes algal bloom, excess growth of algae, especially planktonic algae.
3. It covers the water surface, secrete toxins and reduces the dissolved oxygen content of water.
4. These toxins inhibit the growth of other algae and plants and cause death of aquatic animals.
5. O₂ deficiency may be a cause for death of animals (BOD).
(b) Algal Bloom:
1. A rapid growth of microscopic algae (or) cyanobacteria in water, often resulting in a coloured scum on the surface.
2. Rapid increase of accumulation in the population of algae in fresh water (or) marine water and is recognized by the discoloration in the water from their pigments.

Smog is a type of air pollution caused by tiny particles in the air. The word comes from a mixture of the words smoke and fog.
(i) Smog generally refers to photochemical smog, which is created when sunlight reacts with nitrogen oxides and volatile organic compounds found in fossil fuel emissions from automobiles, factories and power plants.
(ii) These reactions create ground-level ozone and particulate matter, reducing visibility.
(iii) Smog can make breathing more difficult, especially for people with asthma.
(iv) Smog also affects plants and animals. It damages crops as well as causes health problems in pets, farm animals and human beings.
(v) Smog has also been known to cause corrosive damage to buildings and vehicles.

E-Waste:
(i) Electronic waste or e-waste describes discarded electrical electronic devices as well as any refuse created by discarded electronic devices and components and substances involved in their manufacture or use.
(ii) Their disposal is a growing problem because electronic equipment frequently contains hazardous substances.
(iii) In a personal computer, there may be lead (Pb) in the cathode ray tube (CRT) and soldering, compound, mercury (Hg) in switches and housing, and cobalt (Co) in steel components, among other equally toxic substances.
(iv) E-wastes are basically PCB (Polychlorinated biphenyl) based, which are non-degradable.
(v) Used electronics which are destined for I reuse, resale, salvage, recycling or disposal are also considered e-waste.
(vi) Unauthorised processing of e-waste in developing countries can lead to adverse I human health effects and environmental pollution.
(vii) Recycling and disposal of e-waste may involve Significant risk to the health of workers and communities in developed countries and great care must be taken to avoid unsafe exposure in recycling operations and leaking of materials such as heavy metals from landfills and incinerator ashes.
Plastic Waste:
(i) Remedies: '4R' - Refuse, Reduce Reuse and Recycle mantra is the best available remedy for plastic waste pollution.
(ii) Tamil Nadu State government succes implemented the ban on single use plastics from 1st January 2019.

(i) Planting trees in and around noise sources is an effective solution for noise pollution as plants are known to absorb noise and bring down sound levels.
(ii) Regular servicing and tuning of automobile engines can effectively reduce noise pollution by vehicles and machinery.
(iii) Workers should be provided with ear plugs and earmuffs at work sites that generate high noise levels.
(iv) Lubrication of machinery and regular servicing minimizes noise levels.
(v) Regulations should be imposed to restrict the usage of loudspeakers in crowded areas and public places.

(i) Affects all organisms as they depend on the atmosphere for respiration.
(ii) Causes irritation in the throat, nose, lungs and eyes. It causes breathing problems and aggravates existing health conditions such as emphysema and asthma
(iii) Contaminated air reduces the body's defense mechanism and decreases the body's capacity to fight other infections in the respiratory system.
(iv) Frequent exposure to polluted air increases the risk of cardiovascular diseases. Breathing air that is filled with fine particulate matter can induce hardening of the arteries, triggering cardiac arrhythmia or even a heart attack.
(v) Gas leaks can be lethal or affect the quality of air in the affected area.
(vi) CO in the atmosphere interferes with O₂ transport since haemoglobin has greater affinity for carbon monoxide. At low concentration it causes headache and blurred vision. In higher concentration, it can lead to coma and death.

(i) The alteration or changes in the composition of the earth's atmosphere by natural or human activities is called air pollution.
(ii) Increase in carbon dioxide concentration of air is also a form of air pollution. The normal CO₂ concentration in the atmosphere is only about 0.03%. Deforestation is one of the major contributions for increase in carbon dioxide of the air. Forests act as carbon sink by utilizing the atmospheric carbon dioxide for photosynthesis.
(iii) When forests are cut down, the concentration of the atmosphere increases. This leads to global warming or greenhouse effect which is an effect of air pollution.
(iv) Thus by forest conservation, we can reduce the carbon footprint by increased trapping of atmospheric CO₂ and thereby reducing global warming. This leads to reduced levels of air pollution.

(i) Less use of fossil fuels.
(ii) Planting more and more trees.
(iii) Recycling of the wastes to reduce their quantity and produce useful materials.
(iv) Less or no use of fertilizers and pesticides.
(v) Dispose off the solid wastes in landfills.

Deforestation is the destruction of forests in order to clear the land and make it available for other uses.

Any kind of waste that contains infectious material generated by hospitals, laboratories, medical research centers, Pharmaceutical companies and Veterinary clinics are called medical wastes.

RZWT Root Zone Wastewater Treatment
DEWATS Decentralized Wastewater Treatment System

When run-off from land containing nutrients reaches water bodies like lakes, it results in dense growth of plant life. This phenomenon is called Eutrophication.

a) CO₂
b) CFCs
c) Methane
d) Nitrous oxide

Ozone depletion: Thinning of the stratospheric ozone layer is known as ozone depletion. Such depletion causes the 'ozone hole', resulting in poor screening of the harmful UV rays and increase in incidences of skin cancer. Some of the common agents that deplete ozone are CFCs.

Ozone is found in the layer of the atmosphere called stratosphere. It acts as a protective covering that absorbs ultraviolet radiation from the sun. It is found about 15 and 50 kilometers from the ground level.

Air Quality Index (AQI) is a number used by government agencies to communicate to the public how polluted the air is at a given time.

1. Recycling prevents emissions of many greenhouse gases and water pollutants, and saves energy.
2. Using recovered material generates less solid waste.
3. Recycling helps to reduce the pollution caused by the extraction and processing of virgin materials