Curtailing tanneries' pollution

The President of Environmental Society of Pakistan Tanners Association, Aghast Sadden, has said during a presentation at the PCSIR that the pollution content of the effluent released by tanneries can be reduced through the use of environmental friendly inputs in the manufacturing of leather products, says a Recorder Report.
If chemicals used in soaking and lining processes are replaced with enzymes, the pollution load in the effluent can be reduced, and the solid sludge of primary treatment plants can have less hazardous content in it. Even the sludge discharged from tanneries can be turned into fertiliser if chrome is removed from it.
Further, the release of carbon dioxide from sodium sulphide, which causes global warming, can be considerably reduced if sulphides are replaced with enzymes. According to Sadden, the total weight of world bovine hides after salting is approximately seven million tonnes. The volume of carbon monoxide released in the tanning of these hides is equivalent to this chemical element released by as many as 170,000 cars. This shows the contribution of tanning industry in gaseous pollution.
Sadden has claimed that all large tanneries are trying to useless hazardous and environment friendly chemicals. However, a recent sample of liquid tannery effluent has shown unacceptably high concentrations of copper, cadmium, zinc, nickel, and lead per litre. These chemical elements are extremely harmful for human beings, animals and plants. There are around 600 tanneries in Karachi, Lahore, Multan, Kasur, Faisalabad, Peshawar, Gujranwala and Sialkot, with most of the leather production taking place in medium-sized tanneries.
Contrary to what Sadden has implied, even a very few large tanneries have any type of waste treatment facilities, and the liquid waste runoff is often released into the nearest water channel or body of water. Leather tanneries essentially cause three types of pollution: they release extremely hazardous liquid effluents, solid waste and gaseous emissions, if untreated.
Probably the most dangerous are the liquid effluents that contain high concentrations of heavy metals, trimmings, salts, hair and flesh which are discharged, untreated, into fields and other open spaces, ponds, water channels such as canals, rivers and even into the sea. Liquid effluents from tanneries, released into open spaces and fields, are the most dangerous pollutants, as they often seep through underground water table, resulting in the pollution of the entire water supply system, particularly in rural areas.
As chrome tanning is the most widely used method in Pakistan, high concentrations of chromium, aside from nickel and lead released through tannery effluents, is causing birth defects, respiratory disorders, lung cancer, serious skin diseases etc-etc. A majority of the tanneries is clustered in Karachi, where they have had a highly negative impact on city's coastal area. The destruction of mangroves and decimation of shrimp population has badly hurt Pakistan's fishing industry. In Punjab, Kasur has traditionally been a major centre of leather tanning, with at least 230 tanneries operating in this town alone. About 9,000 cubic meters of waste is discharged daily in Kasur, much of which finds its way in waterways, such as canals that criss-cross the agricultural lands of Punjab.
The rest forms pools of stagnant water, or it gradually escapes by seepage through ground to hit underground water table. Tanneries in Pakistan also produce thousands of tonnes of solid waste. This includes 100 to 195 tonnes per day of trimmings, shavings, buffing and packaging materials. A safe disposal of these materials constitutes a formidable challenge. Similarly, untreated gaseous emissions, including ammonia and hydrogen sulphide, are a major source of air pollution in the country, causing serious health problems to people.
While environmental compliance has not been an easy job to carry out in Pakistan, it is unlikely that international standards such as ISO 14001 will make much of an impact on the ground situation. It has been estimated that an investment of $2 billion will be needed in the next decade or so to bring the local environmental standards at par with the international ones. The government should arrange funding for this extremely important project on public-private partnership basis.
Secondly, it should ensure that the recommendations made by Aghast Sadden are implemented in letter and in spirit. Our leather industry has made rapid strides, with the profit earned by leather exporters standing close to $700 million (1998 figure). There is an urgent need for the government to institute urgent measures to help reduce the negative environmental effects of the tanning industry.