States wavering on plan to clean up rivers

The Pioneer, [March 29, 2001]
Yoga Ranptla New Delhi

THE CENTRE’S ambitious plan to rid major rivers of pollution has met with lukewarm response from the states. Some states are dithering to bear their share of the cost, while others are apprehensive and call the plans "half-baked".

The National River Conservation Authority (NRCA) proposes to clean 23 new rivers in 10 states. The authority, represented by Chief Ministers and Members of Parliament, also decided that 30 percent of the cost will be borne by the states. But a few states are reluctant.

Mr. Ranganath Mishra, member of NRCA from Orissa said that the State Government will request the Centre to bear the whole cost of the cleanup operation. Joining him is West Bengal MP Dr Ranjit Kumar Panja who says that the State Government has not yet decided whether it will spare funds for river cleaning programmes. This is when West Bengal is already running the second phase of the Ganga Action Plan.

The Madhya Pradesh Government has been more forthcoming. It will stick to its commitment of 30 percent share of the programme. But is unhappy that other states are turning their backs on the commitment. "If the states will not give their share, they will have no stake in the project. They will not take enough interest (to operate and maintain treatment plants) and the success of the programme is doubtful. This is precisely what has gone wrong with Ganga Action Plan (in Bihar and Uttar Pradesh)," points out Mr. Shivraj Singh Chauhan, Madhya Pradesh MP and member of NRCA.

Other crucial partners are the municipalities. They are the ones to execute the project and go to the public asking them to share the cost of cleanuBut so far municipalities havezbn totally left out of the decision-making process. Says Mr Chauhan, Coordination between municipalities, State Pollution Control Boards and the Centre is lacking." The Centre left it to the Chief Ministers to coordinate with the city machinery. With the exception of Tamil Nadu, other state governments have been casual in taking up the issue.

Whether the states will bear the cost or not, the MPs are in unison that the river cleaning plans should be more comprehensive. Mr Mishra says these are "in somewhat fluid state" while Mr. Chauhan feels they are "halfbated".

"Catchment area development, maintaining minimum flow of water in rivers and diverting treated waste water for irrigation are some of the proposals forwarded by state governments which are yet to be looked into," says Mr Chauhan.

Mr Mishra stressed that the authority needs to develop proper policies. Much of the problem of river pollution lies with raw sewage and industrial effluents flowing into the rivers, which has to stop.

Public participation is the most often used platitude in the Environment Ministry’s documents. But concrete proposals are yet to come by. Barring West Bengal, most states are yet to initiate discussion with the public.

Monitoring of the programmes leaves much to be desired. "For the highly polluted Betwa in Madhya Pradesh, money has been spent on setting up sulabh toilets, con structing bathing ghats and planting trees. Although these are important, by themselves these measures will not improve the quality of water," says Mr Chauhan. The Centre has a tough task ahead to bring all states on board. It must display effective leadership if the Holy rivers of India are to be cleaned.


PFOs / Another class of toxic chemicals: Bioaccumulation causes concern

The Hindu(Sc.& Tech.), [March 29, 2001]

NEW class of compounds may have to be added to the list of recalcitrant pollutants that accumulate in the tissues of animals around the globe. Using a highly sensitive new technique, researchers at Michigan State University have detected traces of a commercially produced polymer, perfluorooctane sulphonate (PFOS), in a surprisingly wide variety of wildlife from Arctic seals to Ganges river dolphins and Mississippi turtles.

But the new results have led environmental chemists to wonder whether the class of compounds to which PFOS belongs, called fluorinated organic compounds (FOCs), might be as much a cause for concern as their notorious cousins, the polychlorinated organic compounds (POCs), which include PCBs (polychlorinated biphenyls) and DDT (dichlorodiphenyltrichloroethane).

The risks of other FOCs remain to be discussed by the regulatory bodies.

There have long been suspicions about FOCs. But there had previously been no way of studying them at the low concentrations found in blood and tissues. "This is a class of chemicals that had not received a lot of attention," says Scott Maybury, a chemist at the University of Toronto, who is trying to develop models to compare the behaviour of FOCs in the environment with that of the well-studied POCs.

John Geisy and Kurunthachalam Kannan of the National Food Safety and Toxicology Center at Michigan State University collected samples of blood or tissue from mammals, birds, fish and reptiles from various parts of the world and tested them for FOCs. They found that some species contained varying levels of other FOCs; all contained PFOS.

Unsurprisingly, PFOS levels were highest in animals found close to urban areas. The surprise was that Geisy and Kurunthachalam also spotted PFOS in animals from pristine environments such as the Arctic. "It got into the bald eagle’s blood, polar bears, fish, birds, everywhere. That surprised me," says Geisy.

PFOS, like other FOCs, consists mainly of carbon and fluorine atoms. It is used to treat carpets, leather, paper and fabrics.

But because it is a large molecule and its atoms are tightly bound together, the chemical is exceedingly stable. So no one thought it would spread in the environment or become concentrated in the food chain a process called bioaccumulation. The suggestion that PFOS can bioaccumulate and has spread worldwide has "blindsided most people", says environmental chemist Tom Cahill of Trent University in Ontario, Canada.

What’s more, because FOCs are so persistent, they may represent even more of a problem than PCBs and DDT. "There’s no known degradative pathway for these compounds," Maybury points out. There is much work still to be done on FOC’s. It is not known how a chemical as inert and non volatile as PFOS is spreading around the globe. Maybury conjectures that volatile or more water-soluble chemical precursors to PFOS may be travelling around the globe and forming PFOS in situ.

It is also unclear whether FOCs are toxic. At 1,000fold higherconcentrations than those found in Giesy’s study, PFOS poisons laboratoryrats. But the effects of low concentrations of the compound on wildlife are not known. "As more species specific information becomes available, are fined . assessment of the risks to wildlife will be possible," says Geisy.

Other FOCs that are still being manufactured or their breakdown products may be of as much concern as PFOS, Geisy warns. "There are over 100,000 synthetic fluorinated compounds, many of them perfluorinated [like PFOS], that people haven’t really looked at," says Geisy. One group in particular, the perfluorinated carboxylates, are widely used to manufacture materials such as fire fighting foams and Teflon.


Eliminating ‘sharkskin’

The Hindu(Sc.& Tech.), [March 29, 2001]

PLASTICS MAY be on the verge of a widespread advance, if researchers can surmount a "fishy" problem. A new technique, called "metallocene catalysis polymerization," enables researchers to manufacture cheap versions of expensive, engineering grade plastics. For example, it can make a version of the common plastic polyethylene so strong that it can stop bullets, says a news release issued by the American Institure of Physics - Inside Science News Service .

However, the new technique often produces an undesired effect, known as "sharkskin," in which the manufactured plastic has a rough surface containing a repeated pattern of ridges. Despite the best attempts of researchers to smooth materials, sharkskin remains a problem.

Now, polymer physicists at the National Institute of Science and Technology have made new insights into the causes and solutions for sharkskin. These insights may help manufacturers to control and eventually eliminate the problem.

Studied since the World War II, sharkskin is actually a problem in many plastic manufacturing techniques. Plastics are made of polymers, long, spaghetti-like chains of molecules made of organic material, which are based on carbon, oxygen, and hydrogen atoms.

Workers make many plastic products in a process similar to pushing pasta through a pasta maker: they force molten polymer mixtures through small holes in a die. For many polymer mixtures, sharkskin forms, marring the desired appearance and texture of the plastic.

Several fixes for sharkskin exist, but none are entirely satisfactory for industry. Sharkskin can be prevented by pushing the polymer slowly through a die, but this is too inefficient for companies wishing to make plastics quickly. It can be prevented by manufacturing the plastic through highly controlled conditions, but this is expensive and impractical for mass production. Manufacturers often use anti-sharkskin additives, but until now it was unclear why they work.

Kalman Migler and his colleagues have performed new experiments that investigate how sharkskin forms and how it can be prevented. Sending polyethylene through a transparent sapphire tube, Migler and colleagues used a high-speed video microscope to watch what happens to polyethylene as it forms sharkskin. With these direct observations, researchers have seen that the polymer undergoes extreme stretching as it passes through the exit hole of the tube, causing the material to rupture.

The polymer splits into two parts, one consisting of the surface of the polymer, and the other consisting of its buried, inner core. The surface of the polymer actually passes slowly, as it sticks to the wall of the tube, but the polymer core passes through quickly. The surface of the polymer accumulates near the wall of the tube and then peels off. Migler and colleagues conclude that this peelingoff of the surface polymer creates the ridges.

In addition, the researchers directly observed why one particular antisharkskin additive is good at preventing sharkskin. The additive, known as a fluoropolymer, was mixed with the polyethylene as the combination traveled through the sapphire tube.

(A fluoropolymer is a polymer in which some of the hydrogen atoms are replaced by fluorine atoms.) In their observations, the researchers found that the polyethylene slips over the fluoropolymer, rather than sticking at the walls.

This dramatically reduces the extreme stretching at the exit, thus inhibiting the formation of sharkskin. Index