Table of Contents
- 1 Solid Wastes
- 2 Hazardous Waste
- 3 Electronic waste | E – WASTE
- 4 Heavy Metal Toxicity And Methods Of Their Prevention
- 5 Occupational Health Hazards
- 6 Treatment and disposal of solid waste
- Solid wastes or municipal solid wastes generally comprise paper, food wastes, plastics, glass, metals, rubber, leather, textile, etc.
- Open-burning reduces the volume of the wastes, although it is generally not burnt to completion and open dumps often serve as the breeding ground for rats and flies.
- Sanitary landfills were adopted as the substitute for open-burning dumps. In a sanitary landfill, wastes are dumped in a depression or trench after compaction, and covered with dirt every day.
- Landfills are also not really much of a solution since the amount of garbage generation specially in the metros has increased so much that these sites are getting filled too.
- Also there is danger of seepage of chemicals, etc. from these landfills polluting the underground water resources.
- Conventional plastics, right from their manufacture to their disposal are a major problem to the environment.
- The land gets littered by plastic bag garbage and becomes ugly and unhygienic.
- Conventional plastics have been associated with reproductive problems in both humans and wildlife.
- Dioxin (highly carcinogenic and toxic) byproduct 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 dioxin and also furan into the atmosphere.
Dioxins are environmental pollutants. They belong to the so-called “dirty dozen” – a group of dangerous chemicals known as persistent organic pollutants (POPs).
The name “dioxins” is often used for the family of structurally and chemically related polychlorinated dibenzo para dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs).
- Plastic bags can also contaminate foodstuffs due to leaching of toxic dyes and transfer of pathogens.
- Careless disposal of plastic bags chokes drains, blocks the porosity of the soil and causes problems for groundwater recharge.
- Plastic disturbs the soil microbe activity. The terrestrial and aquatic animals misunderstand plastic garbage as food items, swallow them and die.
- Plastic bags deteriorates soil fertility as it forms part of manure and remains in the soil for years.
Designing eco-friendly, biodegradable plastics is the need of the hour.
- Polyblend is a fine powder of recycled and modified plastic waste. This mixture is mixed with the bitumen that is used to lay roads.
- Blends of Polyblend and bitumen, when used to lay roads, enhanced the bitumen’s water repellant properties, and helped to increase road life by a factor of three.
- Thermal power plants producing coal ash/fly ash;
- The integrated iron and steel mills producing blast furnace slag;
- Non-ferrous industries like aluminium, copper and zinc producing red mud and tailings;
- Sugar industries generating press mud;
- Pulp and paper industries producing lime mud;
- Fertilizer and allied industries producing gypsum;
- Pulp and paper: Ligno-sulphate, sodium salts.
- Textile: Caustic soda.
- Distillery: Potassium salts, yeast Fertilizer (phosphatic) Calcium sulphate, fluoride.
- Coke oven: Ammonia, ammonium sulphate, tar, naphthalene, phenol.
- One way to emulate nature is to recycle and reuse the chemicals used in industries instead of dumping them into the environment.
- Industries may interact in such a way that they establish a “resource exchange” programme in which waste of one industry or manufacturer is utilized as raw material by another-industry- similar to food web in nature.
- Use of CNG by automobiles instead of petrol, as an automobile fuel, is an example of cleaner technology which has reduced pollution of the environment.
- Instead of throw away economy which creates huge amount of waste, the manufacturers can make more money if their product is redesigned so that it uses minimum amount of raw materials lasts longer, easy to maintain, repair, remanufacture, reuse or recycle.
- Any substance that is present in the environment or released into the environment causing substantial damage to public health and welfare of the environment is called hazardous substance.
- Any hazardous substance could exhibit any one or more of the following characteristics: toxicity, ignitability, corrosivity or reactivity (explosive). Thus, any waste that contains hazardous or very hazardous substance is called hazardous waste.
- Hazardous wastes can originate from various sources such as: house-hold, local areas, urban, industry, agriculture, construction activity, hospitals and laboratories, power plants and other sources.
- The hazardous waste when disposed of release a number of environmentally unfriendly substance(s).
- Hospitals generate hazardous wastes that contain disinfectants and other harmful chemicals, and also pathogenic micro-organisms. Such wastes also require careful treatment and disposal. The use of incinerators (destroy, especially waste material, by burning) is crucial to disposal of hospital waste.
|Toxic fumes e.g. Chlorine, polyvinylchloride||Chlorine could cause acid rain|
|Release into water bodies||Chlorophenol, fluorine compounds, aldehydes, SO2, CO||Cause environmental pollution|
|Plastic||Polythene, poly propylene, polyesters etc. on burning release gases||Toxic, ecological pollution|
|Nuclear waste||Hospitals Laboratories||Slow/sustained in medical/agriculture use||Health hazard,
|Agricultural waste||Forms of Nitrogen wastes||Manure/Dung rich in NO3/N022||Accumulate in vegetables, cause methanoglobenemia cyanosis|
|Nitrosamines/ NO3/NO i||Carcinogenic contribute to acid rain|
|N2O – Nitrous Oxide||Greenhouse effect
[NOx – NO, NO2 are global coolers, N2O is greenhouse gas]
|NH3+ (from livestock breeding)||Affect aquatic life; stimulate fungal growth; epiphytes; cause weathering of forests|
|Phosphates||Eutrophication of aquatic environment|
|Phytosanitary product||Insecticides/pesticides/fungicides/herbicides||Enter soil as run off, polluter water table affect aquatic life, carcinogenic, renal failure|
|Methane||Ruminating cattle, fermentation of organic matter||Powerful greenhouse effect|
- Stockholm Convention is an international environmental treaty
- Came into effective in 2004
- Aims to eliminate or restrict the production and use of persistent organic pollutants (POPs).
- POPs are defined as “chemical substances that persist in the environment, bio-accumulate through the food web, and pose a risk of causing adverse effects to human health and the environment”.
Important Listed substances
- Aldrin: Used as a local ectoparasiticide and insecticide
- Heptachlor: Uses as a termiticide (including in the structure of houses and underground), for organic treatment and in underground cable boxes
- Hexachlorobenzene: Use as a chemical intermediate and a solvent for pesticides
- Endrin: Endrin has been used primarily as an agricultural insecticide on tobacco, apple trees, cotton, sugar cane, rice, cereal, and grains.
- Polychlorinated biphenyl: PCB’s commercial utility was based largely on their chemical stability, including low flammability, and physical properties, including electrical insulating properties. They are highly toxic.
- DDT: DDT is the best-known of several chlorine-containing pesticides used in the 1940s and 1950s.
- Basel Convention on the Control of Transboundary Movements of Hazardous Wastes and Their Disposal.
- International treaty that was designed to reduce the movements of hazardous waste between nations.
- Main goal is to prevent transfer of hazardous waste from developed to less developed countries (LDCs).
- It does not address the movement of radioactive waste.
- 182 states and the European Union are parties to the Convention
- Location è Basel, Switzerland
- Rotterdam Convention on the Prior Informed Consent Procedure for Certain Hazardous Chemicals and Pesticides in International Trade.
- Multilateral treaty to promote shared responsibilities in relation to importation of hazardous chemicals.
- The convention promotes open exchange of information and calls on exporters of hazardous chemicals to use proper labeling, safe handling, and inform purchasers of any known restrictions or bans.
- Signatory nations can decide whether to allow or ban the importation of chemicals listed in the treaty..
- The discarded and end-of-life electronic products ranging from computers, equipment, home appliances, audio and video products and all of their peripherals are popularly known as Electronic waste (E-waste).
- 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, however, be considered hazardous if recycled by primitive methods.
|Lead||Used in glass panels and gaskets in computer monitors
Solder in printed circuit boards and other Components
|Lead causes damage to the central and peripheral nervous systems, blood systems, kidney and reproductive system in humans. It also effects the endocrine system, and impedes brain development among children.
Lead tends to accumulate in the environment and has high acute and chronic effects on plants, animals and microorganisms.
|Cadmium||Occurs in SMD chip resistors, infra-red detectors, and semiconductor chips
Some older cathode ray tubes contain cadmium
|Toxic cadmium compounds accumulate in the human body, especially the kidneys.|
|Mercury||It is estimated that 22 % of the yearly world consumption of mercury is used in electrical and electronic equipment
Mercury is used in thermostats, sensors, relays, switches, medical equipment, lamps, mobile phones and in batteries
Mercury, used in flat panel displays, will likely increase as their use replaces cathode ray tubes
|Mercury can cause damage to organs including the brain and kidneys, as well as the foetus. The developing foetus is highly vulnerable to mercury exposure. When inorganic mercury spreads out in the water, it is transformed to methylated mercury which bio-accumulates in living organisms and concentrates through the food chain, particularly via fish.|
Chromium VI 29
|Chromium VI is used as corrosion protector of untreated and galvanized steel plates and as a decorative or hardener for steel housings Plastics (including PVC): Dioxin is released when PVC is burned.
The largest volume of plastics (26%) used in electronics has been PVC. PVC elements are found in cabling and computer housings.
Many computer moldings are now made with the somewhat more benign ABS plastics
|Chromium VI can cause damage to DNA and is extremely toxic in the environment.|
|BFRs are used in the plastic
housings of electronic
|Barium||Barium is a soft silvery-white metal that is used in computers in the front panel of a CRT, to protect users from radiation||Studies have shown that short-term exposure to barium causes brain swelling, muscle weakness, damage to the heart, liver, and spleen.|
|Beryllium||Beryllium is commonly found on motherboards and finger clips
It is used as a copper- beryllium alloy to strengthen connectors and tiny plugs while maintaining electrical conductivity
|Exposure to beryllium can cause lung cancer. Beryllium also causes a skin disease that is characterized by poor wound healing and wart like bumps. Studies have shown that people can develop beryllium disease many years following the last exposure.|
|Toners||Found in the plastic printer cartridge containing black and color toners.||Inhalation is the primary exposure pathway, and acute exposure may lead to respiratory tract irritation. Carbon black has been classified as a class 2B carcinogen, possibly carcinogenic to humans. Reports indicate that colour toners (cyan, magenta and yellow) contain heavy metals.|
|Phosphor is an inorganic
chemical compound that is applied as a coat on the interior of the CRT faceplate.
|The phosphor coating on cathode ray tubes
contains heavy metals, such as cadmium, and other rare earth metals, for example, zinc, vanadium as additives. These metals and their compounds are very toxic. This is a serious hazard posed for those who dismantle CRTs by hand.
Q1: Due to improper/indiscriminate disposal of old and used computers or their parts, which of the following are released into the environment as e-waste?
Select the correct answer using the codes given below.
- 1, 3, 4, 6 and 7 only
- 1, 2, 3, 5 and 6 only
- 2, 4, 5 and 7 only
- 1, 2, 3, 4, 5, 6 and 7
Heptachlor is a Chlorohydrocarbon (CHC) which is used as an insecticide.
Plutonium is a radioactive metal and hence not used in computers.
So, answer should not contain either 4) or 7).
Answer: b) 1, 2, 3, 5 and 6 only
- India generates about 18.5 lakh metric tonnes (MT) of electronic waste every year, with Mumbai and Delhi-NCR accounting for the biggest chunk. The figure is likely to reach up to 30 lakh MT per year by 2018.
- Bangalore, Chennai, Kolkata, Ahmadabad, Hyderabad, Pune, Surat and Nagpur are other important cities generating substantial amount of e-waste.
- Among the eight largest e-waste generating states, Maharashtra ranks first followed by Tamil Nadu (2nd), Andhra Pradesh (3rd), Uttar Pradesh (4th), Delhi (5th), Gujarat (6th), Karnataka (7th) and West Bengal (8th).
- Over half of the e-wastes generated in the developed world are exported to developing countries, mainly to China, India and Pakistan, where metals like copper, iron, silicon, nickel and gold are recovered during recycling process.
- Unlike developed countries, which have specifically built facilities for recycling of e-wastes, recycling in developing countries often involves manual participation thus exposing workers to toxic substances present in e-wastes.
- Toxic metals are dispersed in the environment through metal smelting industrial emissions, burning of organic wastes, automobiles and coal based power generation.
- Heavy metals can be carried to places far away from their source of origin by winds when they are emitted in gaseous form or in form of fine particulates.
- Rain ultimately washes the air having metallic pollutants and brings them to the land and to water bodies.
- Heavy metals may endanger public health after being incorporated in food chain.
- Heavy metals cannot be destroyed by biological degradation.
- Incidence of heavy metal accumulation in fish, oysters, mussels, sediments and other components of aquatic ecosystems have been reported from all over the world.
- The heavy metals often encountered in the environment include lead, mercury, arsenic, chromium. These are known to cause toxic effects in living organisms.
- Lead enters the atmosphere from automobile exhaust. Tetraethyl lead (TEL) was added to petrol as an anti-knock agent for smooth running of automobile engines.
- TEL has now been replaced by other anti-knock compounds to prevent emission of lead by automobiles. Lead in petrol is being phased out by introduction of lead free petrol.
- Many industrial processes use lead and it is often released as a pollutant. Battery scrap also contain lead. It can get mixed up with water and food and create cumulative poisoning.
- Lead can cause irreversible behavioral disturbances, neurological damage and other developmental problems in young children and babies. It is a carcinogen of the lungs and kidneys.
- In Japan, mass mercury poisoning (Minamata disease) was observed in 1960s, caused by eating fish from Minamata Bay which were contaminated with methyl mercury.
- Largest source of mercury pollution is through aquatic animals such as fish which accumulate mercury as methyl mercury.
- Mercury kills cells in the body and damages organs which come in contact with mercury and thus impairs their functioning.
- Inhalation of mercury vapours is more dangerous than its ingestion.
- Chronic exposure causes lesions in the mouth and skin and neurological problems.
- Typical symptoms of mercury poisoning are irritability, excitability, loss of memory, insomnia, tremor and gingivitis.
- Exposure to mercury can be prevented by taking care that mercury is not released in the environment as well as by replacing mercury by other materials.
- Mercury thermometers used earlier are getting replaced by mercury free thermometer.
- Arsenic is associated with copper, iron and silver ores.
- Arsenic is also emitted from fossil fuel burning.
- Liquid effluents from fertilizer plants also contain arsenic.
- Ground water contamination with arsenic is very common in areas where it is present.
- Chronic arsenic poisoning causes melanosis and keratosis (dark spots on the upper chest, back and arms are known as melanosis. The next stage is keratosis in which palms become hard) and leads to loss of appetite, weight, diarrhoea, gastrointestinal disturbances and skin cancer.
- Surface waters are generally free from arsenic pollution and should be preferred for drinking and cooking.
- Alternatively the tube well/ hand pump water should be purified to remove arsenic before consumption. Techniques for removing arsenic from water are available.
- Mining especially of zinc and metallurgical operations, electroplating industries, etc. release cadmium in the environment.
- It may enter the human body by inhalation or from aquatic sources including fish, etc.
- It may cause hypertension, liver cirrhosis, brittle bones, kidney damage and lung cancer.
- Itai-itai disease first reported from Japan in 1965 was attributed to cadmium contamination in water and rice caused by discharge of effluents from a zinc smelter into a river.
- Metals such as zinc, chromium, antimony and tin enter food from cheap cooking utensils.
- Preserved foods stored in tin cans also cause contamination by tin.
- Zinc is a skin irritant and affects pulmonary system.
- Problems of heavy metal toxicity can be prevented by avoiding the use of utensils made from materials containing these heavy metals or use of drinking water and consuming fish having these heavy metals.
- In coal mining areas coal dust is the main air pollutant. The deposits of coal dust makes miners lungs look black instead of a healthy pink and hence the name black lung disease.
- Black lung disease is the common name for pneumoconiosis (CWP) or anthracosis, a lung disease of older workers in the coal industry, caused by inhalation over many years, of small amounts of coal dust.
- The particles of fine coal dust accumulate in lungs. Eventually this build-up causes thickening and scarring making the lungs less efficient in supplying oxygen to the blood.
- In some cases a progressive massive fibrosis develops, in which damage continues in the upper parts of the lungs even after exposure to dust has ended.
- X-rays can detect black lung disease before it causes any symptoms.
- Workers in mining, manufacturing and construction industries are exposed to high levels of noise which is a very important stress factor.
- Sound levels higher than 80 to 90 dB for more than eight hours are harmful to human ear. Some of the adverse effects of sound are –
- Noise leads to emotional disturbances such as annoyance, disturbed sleep, lack of concentration and reduced efficiency.
- Auditory fatigue – Occurs when noise level is in the range of 85 to 90 dB e.g. noise of a food blender.
- Deafness or impaired hearing – It may be temporary or permanent. Temporary hearing loss occurs on continuous exposure to noise as in case of telephone operators.
- Repeated or continuous exposure to noise more than 90 dB may result in permanent loss of hearing.
- Interference with speech and communication.
- Annoyance: Most people are annoyed by noise and some may become neurotic. Neurotic people lose their temper quickly and become irritable.
- Efficiency: High level of noise at the work place reduces working efficiency. Quiet environment helps in increasing efficiency.
- General change in the body: Exposure to noise increases blood pressure, pulse rate, breathing and sweating or headache.
- Workers in many industries are exposed to chemicals which are hazardous and may be even carcinogenic such as in textiles, cement and construction industries.
- Substances such as benzene, chromium, nitrosamines and asbestos may cause cancers of lung, bladder, skin, mesothelium, liver, etc.
- Occupational asthma is caused due to exposure to organic dusts, microorganisms, bacteria, fungi and moulds and several chemicals.
- Silicosis first reported from Kolar gold mines in 1947 is a common disease among miners, pottery and ceramic industry workers.
- Pneumoconiosis and byssinosis are common among mica and textile industry workers respectively.
- Open dumps refer to uncovered areas that are used to dump solid waste of all kinds.
- The waste is untreated, uncovered, and not segregated. It is the breeding ground for flies, rats, and other insects that spread disease.
- The rainwater runoff from these dumps contaminates nearby land and water thereby spreading disease. Treatment by open dumps is to be phased out.
- It is a pit that is dug in the ground. The garbage is dumped and the pit is covered with soil everyday thus preventing the breeding of flies and rats.
- After the landfill is full, the area is covered with a thick layer of mud and the site can thereafter be developed as a parking lot or a park.
- Problems – All types of waste are dumped in landfills and when water seeps through them it gets contaminated and in turn pollutes the surrounding area. This contamination of groundwater and soil through landfills is known as leaching.
- Sanitary landfill is more hygienic and built in a methodical manner to solve the problem of leaching.
- These are lined with materials that are impermeable such as plastics and clay, and are also built over impermeable soil. Constructing sanitary landfills is very costly.
- The process of burning waste in large furnaces at high temperature is known as incineration.
- In these plants the recyclable material is segregated and the rest of the material is burnt and ash is produced.
- Burning garbage is not a clean process as it produces tonnes of toxic ash and pollutes the air and water.
- A large amount of the waste that is burnt here can be recovered and recycled. In fact, at present, incineration is kept as the last resort and is used mainly for treating the infectious waste.
- 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.
- Pyrolysis of carbonaceous wastes like firewood, coconut, palm waste, corn combs, cashew shell, rice husk paddy straw and saw dust, yields charcoal along with products like tar, methyl alcohol, acetic acid, acetone and fuel gas.
- Composting is a biological process in which micro-organisms, mainly fungi and bacteria, decompose degradable organic waste into humus like substance in the presence of oxygen.
- This finished product, which looks like soil, is high in carbon and nitrogen and is an excellent medium for growing plants.
- It increases the soil’s ability to hold water and makes the soil easier to cultivate. It helps the soil retain more plant nutrients.
- It recycles the nutrients and returns them back to soil as nutrients.
- Apart from being clean, cheap, and safe, composting can significantly reduce the amount of disposable garbage.
- It is also known as earthworm farming. In this method, Earth worms are added to the compost. These worms break the waste and the added excreta of the worms makes the compost very rich in nutrients.
- Four R’s – Reduce, Reuse, Recycle and Recover.
- WMC helps Small and Medium Industrial Clusters in waste minimization in their industrial plants.
- This is assisted by the World Bank with the Ministry of Environment and Forests acting as the nodal ministry.
- The project is being implemented with the assistance of National Productivity Council (NPC), New Delhi.
- The initiative also aims to realize 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.
- The policy also recognizes that citizens and non-governmental organizations play a role in environmental monitoring, therefore, enabling them to supplement the regulatory system and recognizing their expertise where such exists and where their commitments and vigilance would be cost effective.