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Water Pollution
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Water pollution occurs when various substances—organic, inorganic, biological, radiological, or thermal—are introduced into water bodies, deteriorating their quality to the point where the water becomes unsuitable for use.
- Putrescibility refers to the breakdown of organic matter in water by microorganisms, a process that consumes dissolved oxygen (DO).
- When the DO level drops below 8.0 mg/L, the water is considered contaminated, while levels below 4.0 mg/L indicate severe pollution.
- Water pollution by organic wastes is measured in terms of Biochemical Oxygen Demand-(BOD). BOD is the amount of dissolved oxygen needed by bacteria in decomposing the organic wastes present in water.
- Chemical Oxygen Demand (COD) is a slightly better mode used to measure pollution load in water. It is the measure of oxygen equivalent to the requirement of oxidation of total organic matter (i.e. biodegradable and non- biodegradable) present in water.
- A crippling deformity called Minamata disease due to consumption of fish captured from mercury contaminated Minamata Bay.
- Water contaminated with cadmium can cause itai-itai disease also called ouch-ouch disease (a painful disease of bones and joints) and cancer of lungs and liver.
- The compounds of lead cause anaemia, headache, loss of muscle power and bluish line around the gum.
- Excess nitrate in drinking water reacts with hemoglobin to form non -functional methaemoglobin, and impairs oxygen transport. This condition is called methemoglobinemia or blue baby syndrome.
Over exploitation of ground water may lead to leaching of arsenic from soil and rock sources and contaminate ground water. Chronic exposure to arsenic causes black foot disease. It also causes diarrhoea, -peripheral neuritis, hyperkeratosis and also lung and skin cancer.
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Soil Pollution
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- Industrial waste includes chemicals such as mercury, lead, copper, zinc, cadmium, cyanides, thiocynates, chromates, acids, alkalies, organic substances etc.
- Four R’s: Refuse, Reduce, Reuse, and Recycle.
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Noise Pollution
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- Sound is measured in decibels (dB). An increase of about 10 dB is approximately double the increase in loudness.
- A person’s hearing can be damaged if exposed to noise levels over 75 dB over a prolonged period of time.
- The World Health Organization recommends that the sound level indoors should be less than 30 dB
- Noise Level Monitoring – Noise Pollution (Control and Regulation) Rules, 2000 define ambient noise levels for various areas as follows-
(i) Industrial Area- 75DB to 70Db (Day time-6 am to 10 pm and night time 10pm to 6am..75 is day time and 70 is night time)
(ii) Commercial Area- 65 to 55
(iii) Residential Area- 55 to 45
(iv) Silence Zone- 50 to 40
- The Government of India on Mar 2011 launched a Real time Ambient Noise Monitoring Network.
- Under this network, in phase- 1, five Remote Noise Monitoring Terminals each have been installed in different noise zones in seven metros (Delhi, Hyderabad, Kolkata, Mumbai, Bangalore, Chennai and Lucknow).
- In Phase II another 35 monitoring stations will be installed in the same seven cities.
- Phase III will cover installing 90 stations in 18 other cities.
- Phase-II cities are Kanpur, Pune, Surat, Ahmedabad, Nagpur, Jaipur, Indore, Bhopal, Ludhiana, Guwahati, Dehradun, Thiruvananthapuram, Bhubaneswar, Patna, Gandhinagar, Ranchi, Amritsar and Raipur.
- Silence Zone is an area comprising not less than 100 metres around hospitals, educational institutions, courts, religious places or any other t area declared as such by a competent authority.
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Radioactive Pollution
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- Non-ionising radiations affect only those components which absorb them and have low penetrability. They include short-wave radiations such as ultraviolet rays, which forms a part of solar radiation. Sunburns is due to these radiation
- Ionising radiations have high penetration power & cause breakage of macro molecules They include X-rays, cosmic rays and atomic radiations -(radiations emitted by radioactive elements
- Alpha particles, can be blocked by a piece of paper and human skin. Beta particles can penetrate through skin, while can be blocked by some pieces of glass
- Gamma rays can penetrate easily to human skin and damage cells on its way through, and metal.
- Reaching far, and can only be blocked by a very thick, strong, massive piece of concrete radium-224, uranium-238, thorium-232, potassium-40, carbon-14, etc.
- The nuclear arms use uranium-235 and plutonium-239 for fission and hydrogen or lithium as fusion material
- The radio nuclides with long half-time are the chief source of environmental radioactive pollution.
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E-Waste
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- E-waste is not hazardous if it is stocked in safe storage or recycled by scientific methods or transported from one place to the other in parts or in totality in the formal sector. The e-waste can be considered hazardous if recycled by primitive methods
- Survey was carried out by the Central Pollution Control Board (CPCB) during 2005
- In India, among top ten cities; Mumbai ranks first in generating e-waste followed by Delhi, Bangalore, Chennai, Kolkata, Ahmadabad, Hyderabad, Pune, Surat and Nagpur.
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Solid Waste
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- The discarded (abandoned or considered waste-like) materials in irrigation return flows or industrial discharges, Conventional plastics have been associated with reproductive problems in both.
- Does not include solid or dissolved materials in domestic sewage, or solid or dissolved humans and wildlife.
- Solid Waste Management
- Dioxin (highly carcinogenic and toxic) by-product of the manufacturing process is one of the chemicals believed to be passed on through breast milk to the nursing infant.
- Burning of plastics, especially PVC releases this dioxin and also furan into the atmosphere.
- Pyrolysis-It is a process of combustion in absence of oxygen or the material burnt under controlled atmosphere of oxygen. It is an alternative to incineration. The gas and liquid thus obtained can be used as fuels.
Waste Minimization Circles (WMC)
- Helps Small and Medium Industrial Clusters in waste minimization in their industrial plants, assisted by the World Bank with the Ministry of Environment and Forests acting as the nodal ministry.
- Being implemented with the assistance of National Productivity Council (NPC), New Delhi.
- Aims to realise the objectives of the Policy Statement for Abatement of Pollution (1992), which states that the government should educate citizens about environmental risks, the economic and health dangers of resource degradation and the real economic cost of natural resources.
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