About Hornbill Watch

About Hornbill Watch

  • Hornbill Watch is an online platform created to record public sightings of hornbills from anywhere in India.
  • Hornbill Watch was launched in 2014 by Nature Conservation Foundation (NCF) and Conservation India (CI).
  • It is a citizen science project to encourage birders, nature enthusiasts, and photographers to share information on hornbill presence, behaviour, and conservation-related issues.
  • The primary objective of the initiative is generating baseline information using sight records.
  • It is aimed at enabling long-term monitoring of hornbills in India.

Significance of the Initiative

  • Hornbills are slow breeding group of birds.
  • Thus, they are vulnerable to threats from anthropogenic pressures like hunting and deforestation.
  • There is a significant knowledge gap about their distribution, population size, and adaptations to rapidly changing habitats.
  • Furthe,r most research and conservation efforts are often focused on single or few species within protected areas.
  • Besides, currently data collection efforts focusing Hornbills were restricted to experienced birders.
  • Thus, a citizen initiative reaches out to a larger demographic with contributions coming in from photographers and lay people.

Report card of Hornbill Watch

  • Between June 2014 and February 2017, Hornbill Watch received 938 records from 430 contributors across India.
  • Most sightings were reported from Karnataka, Maharashtra, Tamil Nadu, Assam, and Arunachal Pradesh.

Species Occurrence

  • India is home to nine hornbill species.
  • The Indian Grey Hornbill was the most reported species (249 records) followed by the Great Hornbill (218).
  • The rare species include Austen’s Brown Hornbill (19), and the endangered Narcondam Hornbill (17).


  • Karnataka, Maharashtra, and Tamil Nadu had the highest number of hornbill reports followed by the two north-eastern Indian states of Assam, and Arunachal Pradesh.
  • Hornbills were reported from both inside (41%), and outside Protected Areas (59%).
  • Further Hornbills were reported from 70 Pas with Namdapha and Manas are reported to have 4 hornbill species.

Indian Grey Hornbill

  • The most reported Indian Grey Hornbill is widespread in India except in north-eastern India.
  • Habitats range from savanna to urban landscapes.

The Great Indian Hornbill

  • Found mostly in moist deciduous and evergreen forests of the Himalayan foothills and the Western Ghats.

Rare Species

  • Narcondam hornbill
  • It is an endangered species restricted to an area of 6 sq.km. of the Narcondam Island in the Andamans.

  • The Vulnerable or near threatened species such as the rufous-necked hornbill, the Austen’s brown hornbill and the great hornbill were observed in several States in northeastern India.

About Hornbills

  • Hornbills are the large birds found in the tropical forests of Asia and Africa.
  • Most Asian species are primarily frugivores.
  • Ecologically they play a critical role as seed dispersers.
  • Thus they enable regeneration of important food plants and help maintain the diversity in tropical forests.
Section : Environment & Ecology

Basel Convention- 1989

Basel Convention– 1989

• Basel convention is formally called as The Basel Convention on the Control of TransboundaryMovements of Hazardous Wastes and Their Disposal.
• The Convention was opened for signature on 22 March 1989, and entered into force on 5 May 1992.
• India ratified the Convention in June 24, 1992.



• The Basel Convention was adopted by the Conference of Plenipotentiaries in Basel, Switzerland, in response to a public outcry, following the discovery, in the 1980s, in Africa and other parts of the developing world of deposits of toxic wastes imported from abroad.
• Environmental awareness and tightening of environmental regulations in the industrialised world during 1970s and 1980s had led to  an increasing public resistance to the disposal of hazardous wastes.
• In accordance with what became known as the NIMBY (Not In My Back Yard) syndrome and to an escalation of disposal costs.
• This in turn led some operators to seek cheap disposal options for hazardous wastes in the developing world, which was lagging in environmental awareness regulations and enforcement mechanisms.
• Against this background, the Basel Convention was negotiated in the late 1980s, and at the time of its adoption its thrust to combat the “toxic trade”.


The overarching objective of the Basel Convention is to protect human health and the environment against adverse effects of hazardous wastes.


• It aims to reduce the movements of hazardous waste between nations, and specifically to prevent transfer of hazardous waste from developed to less developed countries (LDCs)
• The Convention is also intended to :
minimize the amount and toxicity of wastes generated,
to ensure their environmentally sound management as closely as possible to the source of generation, and
to assist LDCs in environmentally sound management of the hazardous and other wastes they generate


• It does not address the movement of radioactive waste.
• The United States have signed the Convention but not ratified it
Section : Environment & Ecology

Issues related to groundwater

Issues related to groundwater

Issues of over-exploitation:

  • The South Asia Ground Water Forum says the region is the largest user of groundwater, accounting for nearly 50% of the total groundwater pumped for irrigation globally. Groundwater abstracted in the Indo-Gangetic basin is about one-fourth of the global total.
  • India, Pakistan, and Bangladesh are, respectively, the first, fourth, and sixth largest users of groundwater globally. India pumps more than the US and China combined — the second and third-largest users, respectively.
  • Drop in water table:
    • More than 60% of wells analysed by the Central Ground Water Board (CGWB) had levels lower than the decadal average (2007-2016) and about a sixth (17.5%) had levels 2 metres or more below the average.
    • Among the major states, Tamil Nadu had 87% of wells showing a dip in groundwater followed by Punjab (85%).
    • These 2017 pre-monsoon numbers are a cause for concern considering that 90% of rural domestic water use is based on groundwater and 70% of water for agriculture comes from aquifers.
    • Just 38% of the wells across states showed a rise in water levels over the decadal average. Even among these, the overwhelming majority are less than 2 metres above the average.




  • Land subsidence:
    • Land subsidence due to groundwater pumping is a problem threatening several Asian cities.
    • Experts now predict that Indian cities, too, are likely to face land subsidence if over-exploitation of groundwater continues unchecked.
  • Environment & safety:
    • Land subsidence and ground rupture can significantly affect the environment and safety of the people.
    • Experts said that land subsidence can be significant in coastal zones along the Bay of Bengal, such as the deltaic regions of the Mahanadi, Godavari, Krishna and Cauvery rivers.
    • Kolkata is already suffering with sinking rates of 10-20mm/year. Ground rupture has been observed in the Indian hinterland, for example in Uttar Pradesh, adds Teatini.
  • Contamination:
    • A recent report warns of a major crisis due to over-extraction and groundwater contamination covering nearly 60% of all districts.
    • It says there is mounting evidence to suggest that 50% of urban water usage comes from groundwater.
  • Example of Uranium contamination:
    • Findings: Many parts of Rajasthan may have high uranium levels in their groundwater, according to a study by researchers at the Duke University in North Carolina, United States, and the Central Groundwater Board of India.
    • Source: The main source of uranium contamination was “natural,” but human factors such as groundwater table decline and nitrate pollution could be worsening the problem.




  • Cases of land subsidence in western countries and in Asia show that the only check against it is the shutdown of pumping wells and supply of potable water through alternative sources.


Additional information:

  • Total static groundwater available in India is about 10,812 bcm.
  • The average groundwater recharge rate of India’s river basins is about 260m³/day.
  • Estimates suggest that India has about 433 bcm of groundwater which is replenished annually through rain and river drainage. Out of that about 398 bcm is utilizable.
  • As per estimates India is pumping out some 190 BCM/yr of underground water a year. Nature is refilling only 120 BCM. So, there is shortfall of 70 BCM per year


Section : Environment & Ecology

About Climate Change Performance Index 2019

About Climate Change Performance Index 2019

  • The Climate Change Performance Index is an instrument designed to enhance transparency in international climate politics.
  • The index evaluates the climate protection performance of 56 countries and the European Union which are together responsible for more than 90% of global greenhouse gas (GHG) emissions.
  • The CCPI fully incor­porates the Paris Agreement measuring the performance of parties based on the promises made and delivered formulated in their Nationally Determined Contributions(NDC).
  • However, it should be noted that the NDCs if fulfilled would still see the global thermometer rise by more than 3C.
  • The CCPI evaluates the countries’ 2030 targets in 4 categories namely
  1. GHG Emissions (40% weightage)
  2. Renewable Energy (20% weightage)
  3. Energy Use(20% weightage)
  4. Climate policy(20% weightage)
  • The CCPI is a joint effort of German watch (an international NGO), New Climate Institute and Climate Action Network (CAN).

Key Findings

  • Overall Index
  • The first 3 places in the CCPI 2019 is left blank as no country performed well enough to reach the ranking very good.
  • In CCPI 2019, Sweden has topped the ranking, followed by Morocco and Lithuania.
  • The bottom most performers are Saudi Arabia, the United States, Iran, Republic of Korea and Chinese Taipei and Australia.
  • India ranks 11th this year improving its standing by three places compared to the previous edition.
  • GHG Emissions Ranking
  • Sweden is the best performing country followed by Egypt, Malta and the United Kingdom.
  • Iran, Republic of Korea and Saudi Arabia are the bottom three countries.
  • In 40 of the 56 countries, emissions went down between 2011 and 2016.
  • However according to recent study by Global Climate Project, global carbon emission is projected to have been risen highest levels (2.7%) in the recorded history in 2018.This is due to growth in fossil fuel use like coal and oil in most regions.
  • India has low level per capita GHG emissions and a relatively ambitious mitigation target for 2030 and thus place 12 in the emissions category.
  • Renewable Energy Rankings
  • Renewable energy is a key driver for mitigating emissions.
  • Latvia leads the ranking of the category, followed by Sweden and New Zealand.
  • Iran, Saudi Arabia and Russia are the bottom three.
  • Under Paris Climate Agreement,India has pledged to generate 40% of its electricity from renewable sources by 2030.
  • However the dominance of coal in its energy mix may pose a risk of offsetting positive developments in the renewable energy sector.
  • Energy Use Rankings
  • While emerging economies tend to perform well in this category, India is rapidly increasing its energy use in the past few years.
  • Despite this India is placed 10th in this category.
  • Climate Policy Rankings
  • Climate policy category is led by Portugal, France, the Netherlands, Sweden and Morocco.
  • Australia, Turkey and the United States form the group of the worst-performing countries.
  • These counties often hinder progress in international negotiations.
Section : Environment & Ecology

About Pondicherry shark

About Pondicherry shark

  • Known as ‘Pala Sora’ in the local parlance, the Pondicherry Shark is on the verge of extinction.
  • Scientifically known as Carcharhinus hemiodon, it belongs to the Carcharhinidae family with a growth of 3.3 feet.
  • It is identified by its black tips of dorsal, pectoral and Tai fins. The front teeth are distinctly serrated at the base and smooth at the tip.
  • The Pondicherry shark was once found throughout Indo-Pacific coastal waters from the Gulf of Oman to New Guinea, and is known to enter fresh water.
  • Until now, the only known sightings of this species since the 1980s are in rivers in Sri Lanka.
  • Fewer than 20 specimens are available for study, and most aspects of its natural history are unknown.
  • The International Union for Conservation of Nature (IUCN) has listed the Pondicherry shark as Critically Endangered.
  • It is probably threatened by intense and escalating fishing pressure throughout its range.
  • The shark is among the 25 “most wanted lost” species that are the focus of Global Wildlife Conservation’s “Search for Lost Species” initiative


IUCN Red List or Red Data List or Red Book

  • The IUCN Red List of Threatened Species, founded in 1964, is the world’s most comprehensive inventory of the global conservation status of biological species.
  • When discussing the IUCN Red List, the official term “threatened” is a grouping of three categories: Critically Endangered, Endangered, and Vulnerable.


When is a species considered as critically endangered?

  • Critically endangered is the highest risk category assigned by the IUCN (International Union for Conservation of Nature) Red List to wild species.
  • There are five quantitative criteria to determine whether a taxon is threatened.
  • A taxon is critically endangered when the best available evidence indicates that it meets any of the following criteria:
  1. Populations have declined or will decrease, by greater than 80% over the last 10 years or three generations.
  2. Have a restricted geographical range.
  3. Small population size of less than 250 individuals and continuing decline at 25% in 3 years or one generation.
  4. Very small or restricted population of fewer than 50 mature individuals.
  5. High probability of extinction in the wild.


Section : Environment & Ecology

About Great Indian Bustard

About Great Indian Bustard

• The Great Indian Bustard is one of the largest flying birdsin the world.
• It is also one of the heaviest flying birds that weigh up to 15 kg.
• It is considered to be the flagship grassland speciesbeing endemic to the grasslands of India.
• Further the great Indian bustard is classified as “critically endangered” in the IUCN Red List.
• Accordingly it a “schedule I species” in the Wildlife (Protection) Act, 1972, requiring similar attentiongiven to tiger in India.
• Desert National Park being the primary habitat of the critically endangered GIB, it is declared the state bird of Rajasthan.


• As mentioned Great Indian Bustard is endemic to grasslands of India.
• Till 1980s, about 1,500-2,000 Great Indian Bustards were spread throughout the western half of India, spanning eleven states.
• The Desert National Park of Rajasthan is a natural habitat for the Great Indian Bustard.
• Being a ‘nomad’, the bird moves around the landscape spanning about 8,000 sq km in Rajasthan’s Jaisalmerdistrict which is aptly called the Great Indian bustard arc.
• In the Thar, the Great Indian Bustard is concentrated mainly about 250 sq km of 3,162 km of the Desert National Park.
• Gujarat’s Kutch province is another home to the bird species which houses India’s second-largest bustard population.

Dwindling population

• While in 1980s there were about 1500-2000 GIBs, this number has dwindled to around 125 birds of which about 100 are in Rajasthan.
• The main reasons for dwindling populaion of Great Indian Bustard are:
✓ Loss of habitat due to declining grasslands
✓ Rampant poaching
✓ Renewable energy projects
✓ Lackadaisical approach in their conservation

Recovery and Conservation Plans

• In 2011, the bird was categorised as “critically endangered” in IUCN Red list.
• The Union Ministry of Environment and Forests prepared a species recovery programme for the Great Indian Bustard in 2017.
• The Rajasthan state government Rajasthan also launched the Project Great Indian Bustard to recover the population of the critically endangered bird. 
• Further it has been classified as schedule 1 species(endangered, threatened or of special concernunder Wildlife (Protection) Act, 1972 with same level of protection as tiger.

Failure of Conservation Plans

• Though GIB is classified as ‘schedule 1’ species under Wildlife (Protection) Act, 1972, they have not received adequate attention like tiger.
• In 2016, the Central government decided to set up captive breeding and hatchery centres in Rajasthan. 
• However captive breeding is challenging for a large bird that is easily injured by living in cages.
• Captive breeding also prolongs the time taken to reach reproductive maturity leading to very low fertility rate.
• Further it is difficult to save GIB in situ as msost of the time it’s outside the protected areas where we have no control over grazing and the laying of the pipelines, wires and roads.

Way Forward

• Setting up the conservation breeding centres as per the 2017 plan.
• Necessary support for setting up of breeding centresshould be extended in expeditious way including land allotment and deploying a scientist to facilitate breeding training.
• While the breeding centres take time, incubation units, which take only few weeks, should be set up in the GIB arc.
• GIB should get the highest priority in the conservation plans.
Section : Environment & Ecology

About Harrier (Bird)

About Harrier (Bird)

  • Harrier, any of about 11 species of hawks of the subfamily Circinae (family Accipitridae).
  • They are plain-looking, long-legged, and long-tailed birds of slender build that cruise low over meadows and marshes looking for mice, snakes, frogs, small birds, and insects.
  • Harriers are about 50 cm (20 inches) long, have small beaks, and their face feathers are arranged in facial discs.
  • They nest in marshes or in tall grass and lay four to six dull whitish or bluish eggs.
  • The best-known harrier is the hen harrier (British), called the northern harrier or marsh hawk in the United States (Circus cyaneus), which breeds in temperate and boreal regions throughout the Northern Hemisphere and in southern South America.
  • Also common are the marsh harrier (C. aeruginosus) and Montagu’s harrier (C. pygargus) ranging over most of Europe and from the Mediterranean shores of North Africa to Mongolia.
  • The pallid harrier (C. macrourus) breeds from the Baltic to southeastern Europe and Central Asia.
  • Allied species include the cinereous harrier (C. cinereus), found from Peru to the Straits of Magellan; the long-winged harrier (C. buffoni), ranging over all of South America, especially east of the Andes; the South African marsh harrier (C. ranivorus), ranging north to Uganda on the east; and the pied harrier (C. melanoleucus), of central eastern Asia.
  • Many of the 14 species in this group, such as the pallid harrier and Montagu’s harrier, are migratory and move to warmer climates for the winter.
  • Some species, such as the African marsh harrier, remain in their breeding territories all year.
  • Every winter, several species of harrier birds travel thousands of kilometres to escape frigid Central Asia for the grasslands of the subcontinent.


Highlights of the news

  • The “poorly studied” harrier species is the focus of a study by two researchers from the Ashoka Trust for Research in Ecology and Environment (ATREE), who compared previous records of sightings with more current observations to determine what many had feared.
  • Researchers collated the data on roosting harriers to analyse trends in their population since the mid-1980s.
  • At least five species of harriers were recorded in India over the years; India has one of the largest roosting sites in the world for Pallid Harriers and Montagu’s Harriers.
  • The researchers focused on six of the 15 major roosting sites in six States, where consistent observations had been made for over five years.
  • In the mid-1990s, an estimated 1,000 birds roosted here.
  • By 2016, the number was down to less than 100 birds.
  • While a general declining trend was observed in all the monitored sites, researchers noted the most dramatic changes at the Rollapadu Bustard Sanctuary in Andhra Pradesh’s Kurnool district, one of the largest.
  • In Hessarghatta on the outskirts of Bengaluru, Western Marsh Harriers declined significantly, leaving the area nearly deserted.
  • The importance of area protection can be seen in the number of birds. While there is a median count of 125 harriers in protected areas, it’s less than half that number — 48 — in unprotected areas.
  • However, the study notes that the population of the species in Central Asia has not seen any drastic changes.
  • So, these results indicates possibilities of:
    • The migrant birds have found better places to roost than India, which the researchers think is improbable.
    • Considering the overall decline is spread out, the numbers could signify a lowering trend in populations.
    • Remarked on the possibility of a combination of multiple factors for the fall.



Possible reasons for decline

  • The gravest concern is the loss of grasslands, either to urbanisation or to agriculture.
  • In February-March, peak season for the arrival of the birds, farmlands are burnt or over-grazed.
  • Of the 15 roosting sites surveyed, eight no longer exist as grasslands, and only five are protected.
  • Excessive use of pesticides in farms in and around the roosting sites could also be a reason for the lowered population counts.
  • In crops such as cotton, the use of pesticides kills grasshoppers, the harriers’ primary prey, and could lead to mortality of the birds themselves as they are on the top of the food chain.


Way forward

  • Globally, of the 16 harrier species, only two are listed as endangered by the International Union for Conservation of Nature, even though most of them are declining.
  • Hence, more intensive research on the bird is needed.
  • The conservation of India’s grasslands could be a start in protecting the magnificent migrators.
Section : Environment & Ecology

Water striders

Water striders
  • They are small insects that are adapted for life on top of still water.
  • By using surface tension to their advantage, they can walk on water.
    • Water acts different at the surface.
    • Water molecules are attracted to each other and like to stay together, especially on the surface where there is only air above.
    • The attraction between water molecules creates tension and a very delicate membrane.
  • Water striders walk on this membrane.

Physical features
  • They are about a half-inch long with a thin body and three sets of legs.
  • They have three pairs of legs.
  • The legs have tiny hairs that repel water and capture air.
  • By repelling water, the tiny water striders stand on the water’s surface and the captured airs allows them to float and move easily.
  • The striders possess needle-like mouth parts that are used for sucking the juice of prey.
  • There front legs are relatively shorter than the mid and hind legs and used to catch and hold prey.
  • They eat insects and larvae on the surface of water, such as mosquitoes and fallen dragonflies.
  • Water striders act as a water quality indicator as they are found on water surface.
  • They play an important role in the food chain by feeding on mosquito larvae.
Subgenus Ptilomera
  • Water striders have many subgenus, one of them is Ptilomera.
  • They are only found in rocky, fast flowing streams and rivers that are not exposed to a lot of sunlight.
  • They  have hair on the middle legs that help the insects resist the strong current of streams.
Ptilomera nagalanda Jehamalar and Chandra
  • It was found in the river Intanki of Peren district.
  • It has orange with black stripes on the dorsal side and a pale yellowish brown ventral part of the body.
  • The presence of black stripes on the dorsal side differentiates this species from other known species of the subgenus Ptilomera.
  • It has long slender legs and measures about 11.79 mm.
Water striders of subgenus Ptilomera found in India
  • So far, only five species of water striders under the subgenus  Ptilomera were known in India. These include:
    1. Ptilomeraagriodes: It is found in peninsular India
    2. Ptilomeraassamensis: It is found in northeastern India
    3. Ptilomeralaticaudata : It is found in northern and northeastern India
    4. Pltilomeraoccidentalis : It is found in Uttarakhand.
    5. Ptilomeratigrina : It is found in the Andaman islands.
  • With the discovery of Ptilomera nagalanda, the number of species of water striders belonging to the subgenus has increased to six.
Section : Environment & Ecology

About Bio-plastics

About Bio-plastics

  • Bioplastic are a category of plastics derived from renewable bio-based resources.
  • Conventional plastics are made from petroleum-based raw materials, bioplastics are made from 20 percent or more of renewable materials.
  • Bioplastic can be both biodegradable and non-biodegradable.
  • Bio-plastics can also be non-biobased but biodegradable.




Types of Bioplastics

Depending on the feedstock used for making bioplastics there are two main types of bioplastics:

PLA (polyactic acid)

  • It is typically made from the sugars in corn starch, cassava or sugarcane.
  • The starch is comprised of long chains of carbon molecules; similar to the carbon chains in plastic from fossil fuels form a long-chain polymer (a large molecule consisting of repeating smaller units) that is the building block for plastic.
  • Hence, it is biodegradable, carbon-neutral and edible.

PHA (polyhydroxyalkanoate)

  • It is made by microorganisms, sometimes genetically engineered, that produce plastic from organic materials.
  • The microbes are deprived of nutrients like nitrogen, oxygen and phosphorus, but given high levels of carbon.
  • They produce PHA as carbon reserves, which they store in granules until they have more of the other nutrients they need to grow and reproduce.
  • Companies can then harvest the microbe-made PHA, which has a chemical structure similar to that of traditional plastics.
  • Because it is biodegradable and will not harm living tissue.
  • PHA is often used for medical applications such as sutures, slings, bone plates and skin substitutes; it is also used for single-use food packaging.


Advantages of Bioplastics

  • Reduced use of fossil fuel resources.
  • Smaller carbon footprint.
  • Bioplastics do produce significantly fewer greenhouse gas emissions than traditional plastics over their lifetime.
  • Faster decomposition.
  • Bioplastic is also less toxic and does not contain bisphenol A (BPA), a hormone disrupter that is often found in traditional plastics.


Bioplastics in India

  • In India there are 16 companies that make bioplastics.
  • In Indian case, bioplastics are those that are biodegradable.



  • Bioplastics are relatively expensive.
  • PLA can be 20 to 50 percent more costly than comparable materials.
  • Since they are made from the byproducts of food crops a bioplastic carry bag could cost almost thrice as much.
  • In order to decompose biodegradable bioplastics we need industrial composter.
  • However, most Indian cities lack facilities to compost bioplastics.
  • Further the raw material used for bioplastics manufacture in India is imported mostly from Europe or China. This makes manufacture of bioplastic expensive in India.
  • While bioplastics degradation is fast in industrial composting facilities, it takes years in the natural environment.
  • This might increase the litter due to wrong perception that bioplastics are naturally decomposed.
  • Bioplastics production results in pollutants, due to the fertilizers and pesticides used in growing the crops.
  • The bioplastics also contributes to more ozone depletion than the traditional plastics, and required extensive land use.


Way Forward

  • Indian companies should manufacture raw material indigenously to bring down the cost.
  • Innovation in feedstock is another way to reduce the cost of industrial composting like use of ‘second-generation” and “third-generation” feedstock
  • For example, feedstock made from tapioca starch and vegetable oil is naturally compostable.
  • The most important innovation is the use of non-food crops like saw dust, organic mixed-waste etc.
  • Another feedstock is algae like it is done in Israel.
  • Further India should have a policy including sops like subsidies for electricity consumption, lower rates of Goods and Services Tax and lower import duties for bioplastic manufacturers.
  • Municipalities should step up in improving composting infrastructure.
  • Further separate recycling streams are necessary to be able to properly discard bioplastics.


Section : Environment & Ecology



  • A tannery is the place where the skins are processed.
  • Tanning hide into leather involves a process which permanently alters the protein structure of skin.
  • The alteration makes it more durable and less susceptible to decomposition and also possibly coloring it.
  • Tanning is a widespread, global industry that works with both light and heavy types of leather.
  • Light leather is generally used for shoes and other soft products such as purses, and heavy leather is used for straps, belts and in various machineries.


Pollution from Tanneries

  • The two main types of tanning are:
  1. Chrome tanning
  2. Vegetable tanning
  • Chromium compounds are applied to protect hides from decay and to make them more durable against moisture and aging.
  • Other materials that may also be used in the pre-treatment and tanning processes include sulfuric acid, sodium chlorate, limestone, and limestone soda ash.
  • Due to the repeated processes of soaking raw hides and wringing them out, the tanning process creates large amounts of wastewater that is contaminated with many different chemicals.
  • Chromium from leather tanning can make its way into air, soil, food, and water, and the most common forms of exposure are through inhalation of dust or fumes and ingestion of or contact with contaminated water.


Pollution hazards of tanaries

  • Continuous discharge of untreated effluents from tannery areas has an adverse effect on water quality, soil and human health.
  • If tannery effluents are discharged on land it may affect ground water quality due to presence of high concentration of chromium and chlorides. It renders the land unsuitable for cultivation due to high salt content.
  • The suspended solids, in the form of lime, hair, flesh etc. settle to the bottom and both lowered dissolved oxygen and suspended solids can harm aquatic life.
  • Tannery effluents are very toxic in nature and have an obnoxious smell. It has alarming levels of Arsenic, Cadmium, Mercury, Nickel and Chromium VI.
  • According to the World Health Organisation, these heavy metals have a lethal impact on public health when they enter the food/ water chain.
  • Diseases caused by heavy metals include Minamata by Mercury, Itai-Itai by Cadmium, Nickel-Itch by Nickel, Black-foot disease by Arsenic and respiratory distress by Chromium VI.
  • Cadmium is a potent kidney toxicant and Mercury is a potent neurological toxicant. Chromium VI is a known human carcinogen.


The Common Effluent Treatment Plant (CETP)

  • Effluent treatment plants need land for construction, capital cost, power and specialized manpower for their operation and maintenance.
  • Because of these constraints, small scale tanneries cannot afford to have their own effluent treatment facilities and therefore, combined effluent from all tanneries is to be brought to a centralized place for treatment. This facility is called a Common Effluent Treatment Plant (CETP).
  • For operation and maintenance of CETP, small scale tanners formed a co-operative society. The expenses for operation and maintenance of CETP are being shared by participating tanneries.
  • Thus Common Effluent Treatment Plant (CETP) is a way by which the small tanneries can treat pollution at cheaper way.


What is no- development zone?

  • ‘No-development zones’ are areas where no construction including commercial or residential buildings can come up.

What is In-Stream Mining?

  • In- Stream Mining involves the mechanical removal of gravel and sand directly from the active channel of rivers and streams. In-stream mining commonly results in opening of the channel bed, which can spread upstream and downstream as well.
Section : Environment & Ecology