Mercury : Danger Signals

Between 1932 and 1968, a company manufacturing petrochemicals and plastics in a small fishing village in Japan dumped 750 kg of mercury compounds every year into the Minamata bay. The first signs of the impact of this dumping surfaced in the mid-1950s: a decline in the fish population, and symptoms of blurred vision, numbness in limbs and speech impairment in people who consumed the fish. Most victims complained of severe convulsions, loss of consciousness, repeated lapses into crazed mental states, and they finally slipped into coma. By 1992, the Minamata tragedy had affected 2,252 people, of whom 1,043 died.

Today, the caustic-chlorine industry in India releases a staggering 60-70 tonnes of mercury every year into our environment. This figure is 75 times the amount of mercury that triggered the Minamata tragedy.

With alarming new data that reveals the dangers of mercury poisoning, a well-known Delhi-based environment NGO - Centre for Science and Environment (CSE) - holds the caustic-chlorine sector responsible for 40 per cent of the mercury pollution in the country. What is particularly disquieting about these emissions is that the Indian companies have no clear idea about how half their mercury is lost or where it vanishes, CSE claims. In its recent ratings on the caustic-chlorine sector, CSE shows that mercury consumption levels in India are one of the highest in the world, approximately 10 per cent of global consumption. However, India does not produce mercury; it relies completely on imports: 170-190 tonnes between 1998-2001.

Mercury-based products like electrical equipment, batteries and thermometers also contribute to high levels of mercury emissions but are not yet monitored, says CSE Director Sunita Narain. According to her, government action in this direction has been tardy. Alerted to the hazardous nature of mercury, a ban was issued in 1986 on the setting up of new mercury-based caustic-chlorine plants. But the existing plants were allowed to operate. As a result, there has been no significant reduction in mercury pollution.

The Green Rating Project (GRP) of CSE also says that, unlike most developed countries where mercury cells have been given a timeframe to close down, no such timeframe has been stipulated by the Indian government. The rating of the caustic-chlorine sector took over a year and covers about 90 per cent of the caustic-chlorine industry. The study assessed 25 production facilities spread across 11 states and one Union Territory.

The official version, however, tells a different tale. Dilip Biswas, Chairman of the Central Pollution Control Board (CPCB), clarifies that it was in 1996 and not 1986 that a ban was enforced on establishing new plants based on mercury cell technology. Over the years, he says, as many as 60 
per cent of mercury-based caustic-chlorine plants in the country have shifted from mercury cell technology to membrane cell technology. The membrane cell process is recommended as a viable alternative as it does not use mercury. "Two years ago we recommended to the Environment Ministry that the remaining mercury cell-based plants should be phased out by 2005," he declares.

Biswas cautions against the alarmist note rung by the CSE study. In fact, he says, the major findings of this study and its recommendations are a duplication of a similar study undertaken by the CPCB about two years ago, after which the Board's suggestions were forwarded to the Environment 
Ministry for follow-up action.

But environment activists argue that the GRP findings only reinforce the need to urgently tackle what could well portend an environmental and health disaster for the country. Well-known environmentalist Vandana Shiva points out that the very fact that a watchdog environment group has brought out 
similar data and recommendations to those prepared by the government earlier only shows a failure of the regulatory process to act effectively. "This is symptomatic of the mood in the country where there is total disregard for hazardous technologies."

What is clear from the GRP analysis is that existing mercury cell companies in India just cannot meet the mercury emission standards being followed by European countries. It would be virtually impossible for the Indian companies to reduce their mercury emissions even below 50 grams per tonne caustic soda unless they decide to upgrade the technology substantially. And upgrading implies a very costly investment.

Besides, even if mercury emissions are reduced to 50 gm per tonne caustic soda, the total emissions from Indian mercury cells would still be about 20 tonnes per annum - about 32 times more than existing emissions in Europe - to produce equivalent caustic soda, GRP points out. So, it is a big public health risk to allow companies whose economic life has not yet expired to operate.

CSE also has reservations about the switch from mercury to membrane cell technology. A key finding of GRP is that partial shifting of mercury cell to membrane cell is causing more environmental pollution than good. In these production plants, mercury cells release more mercury and their membrane cells too consume more energy and raw materials. GRP has found that instead of a decrease, there is an increase in the specific mercury pollution from these plants.

Biswas disagrees with this contention. Explaining the mercury cell process, he says it requires good quality chemical grade brine. "If you don't have this, there is a possibility of consuming more and more mercury and more sludge is generated."

The good news however, is that not all of this mercury causes pollution. "The mercury is mixed with brine mud in bonded form which is not released into the environment. This brine mud is secured in landfills located within the plant," Biswas adds.

According to CSE's Narain, the focus of regulations for pollution from mercury cell plants in India is on placing checks on mercury concentration from various point sources rather than putting a check on total mercury pollution load entering the environment.

Observing that the "deadly mercury trail" still leaves many issues unanswered, the CSE Director calls for urgent action to set new regulations for existing mercury-based plants. If nothing else works, these plants should be closed down as fast as possible. "It is clear with the data we have on mercury that a massive human tragedy is in the making."  


More by :  Nitin Jugran Bahuguna

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