Social and economic cost of tanneries
By Syed M. Aslam
Oct 23 - 29, 2000
A sinister collusion between tanneries and poultry farmers is posing
grave danger to the health and the lives of millions of unsuspecting chicken lovers in
Karachi. What you read here may compel you to stop eating chicken meat altogether.
What is putting the lives of millions in peril is an unholy alliance
between the tanneries and poultry farmers, to respectively supply and use deadly toxic
waste, as poultry feed. The leather tanning waste include such hazardous substances as
chromium, sulphides, ammonia and nitrogenous compounds. All of these elements are used
during the tanning process to remove the hair and flesh to give quality finish to the raw
skins and hides. The resultant waste produced in bulk every single day at the tanneries is
seen fit to be used as poultry feed for the benefit of both the poultry farmers and
tanneries' operators. It helps the former to buy a cheap feed and the later to make money
for an otherwise good-for-nothing waste oblivious to grave dangers which it poses to the
The highly improper practice for monetary gains is not an stealth or
unknown activity. The tanners and the poultry farmers both are well aware of it. Kamal
Shahryar, the project director of Environmental Management Project for Korangi Tanneries
which houses the biggest cluster of leather treatment plants anywhere in the country, said
he was aware of the use of toxic poultry feed. He was answering a question at a discussion
held at The British Council here last week on 'The price of leather: social, political and
economic costs of tanneries in Karachi.
In his presentation Kamal said that leather tanning is a
water-intensive process. A kilogram of skin or hide requires 40 litres of water though
many tanneries use as much as 90 litres of water. Highlighting the contribution of cluster
of tanneries located in Korangi he said they contribute one-third to the total leather
exports of the country. Putting the number of tanneries at Korangi at 170, a figure which
is put twice that much by the independent observers, he said that they cumulatively
generate a solid waste which fluctuates between 95 tonnes to 200 tonnes a day depending on
While SITE and Shershah areas of Karachi also house tanneries, there
they are spread all over like those located in other parts of the country. Much has been
written about Korangi tanneries and their adverse effect on the environment and pollution
land, air, surface, underground but the latest disclosure of toxic tannery waste
used as chicken feed gives an altogether different human dimension to a problem which has
been there all along. Can we ignore to sleep on a problem which puts millions of human
lives at grave risks?
Obviously not. It is ironic that while leather plays a vital role in
the economy of Pakistan, the tanneries are posing a grave threat to the environment and
human lives to the complete indifference of the authorities. In last decade the percentage
share of leather in the exports has increased by an average of over 8 per cent which is
second only to 60.2 per cent increase registered in cotton commodity group. The production
of hides and skins increased from 7.3 million to 7.6 million and 35.3 million to 37.2
million respectively during 1997-98 1999-2000.
The tanning process causes environmental degradation on surface waters,
air, land, groundwater and sewerage. It results in rapid deterioration of physical,
chemical and biological qualities of surface water causing noxious odors from the
decomposition of organic matters such as hair and skin and depletion of dissolved oxygen
necessary for the aquatic life. Chromium, sulphides and ammonia cause toxicity while algae
growth caused by nitrogenous compounds suffocates aquatic life.
The untreated waste from the tanneries adversely affect the fertility
of the soil and causes land pollution due to presence of untreated effluents and sludge.
It also affect the quality of groundwater through seepage of water and chemicals polluting
it with such deadly combination as chlorides, tannings, chromium, sulphate, sulphides,
traces of organic chemicals and solvents as well as high nitrogen level each of which is a
health hazard. As groundwater takes a long time to clean itself due to its slow movement
and having no contact with air the incessant seepage of tannery waste poses a serious
hazard to human health.
The tanning process also results in deposition of solids in the sewers
and sewage treatment works. It results in encrustation of calcium carbonate in sewers and
excessive sulphides or sulphate level accelerate corrosion and deterioration of concrete
or cement of pipes. It also have a direct impact on the quality of air due to sulphide and
ammonia emissions during de-hairing and waste treatment process.
With the exception of two the hundreds of tanneries in the Korangi
Industrial Area do not have any in-house waste treatment plant. These units use large
quantity of water and generate 36 million litres of effluents everyday besides various
types of solid wastes creating serious pollution problems particularly those who work or
live around the Korangi tanneries.
According to Nuzhat Ahmed of Centre for Molecular Genetics, University
of Karachi, significant proportion of the population in the Korangi area is employed as
tannery workers. Citing a health survey of tannery workers, she said, indicates a high
prevalence of common symptoms like backache, expectorant cough, skin lesions, breathing
problems, common cold and watering/red eyes.
But the impact of hazardous pollution in Korangi tanneries is not
restricted to its immediate surroundings and area. It poses risks to the lives of millions
of unsuspecting people eating chickens fed on toxic feed or vegetable farms irrigated by
waters mixed with chemicals: Liquid discharge from Korangi tanneries flow into the drain
which runs through the Korangi area and finds its ways into surface waters which is used
to irrigate number of vegetable farms.
Whatever awareness and little progress made to improve the working
environment of tanneries in Pakistan can be attributed to international pressure. The
production of smaller goat and sheep skins and bigger cow and buffalo hides have
registered an increase of 14 per cent and 30 per cent during the last decade. The
production of skins has increased from 32.7 million to 37.2 million while that of hides
has increased from 5.9 million to 7.6 million. The increased production highlights the
increased pressure on tanneries to turn skins and hides into quality leather, a process
which poses serious environmental problems in the absence of proper treatment methods,
both during and after the process at individual and collective levels.
The environmental problems caused by the Korangi tanneries and the
grave risks which they pose to the human health should be seen in the broader perspective.
If Korangi tanneries are seen it fit to generate extra cash by selling the toxic feed to
poultry farmers it would be naive to suggest that other tanneries in Shershah, SITE and
other parts of the country are not aware of it. It is time for the Environmental
Protection Agency Sindh to investigate an issue which poses serious risks to public
health. It is also time for the researchers and professional medical bodies to evaluate
the quality of chicken meat available in the market and its impact on human health.
The pollution caused by tanneries could be checked through in-house
improvements in better operation and maintenance methods by individual units as well as
installation of a collective treatment plant for the effluents. Recovered Chromium costs
not only one-third the price of new chromium but is also as good. Similarly, dusted salt
is also retrieved for reuse. With better management solid waste can be disposed of in a
least polluting manner. Occupational injury, accidents and hazards can be avoided by
providing essential personal safety equipment to the tannery workers and industrial safety
measures. Diligent management can help to minimise the use of hazardous chemicals.
To promote safety hazardous machines used in the tanneries should be
equipped with appropriate protecting devises. Improving the lighting, space, ventilation
and work-floor conditions can help reduce accidents and workers should be educated about
emergency contingencies. The drainage system should be improved to avoid formation of
hydrogen sulphide gas within the premises of a tannery.
Chromium and bio-gas can be recovered from tannery effluents, the later
is possible through proper biological treatment. A certain types of solid waste can also
be recycled and reused. Some of these wastes including raw hide trimmings, leather
trimmings are used in the manufacture of gelatin, leather boards and fertilizers etc.