1. The word 'mercury' is a part of our popular vocabulary, but what are its specific features and characteristics?
Mercury is a silvery, odourless, highly volatile, metallic element, which is in liquid form at room temperature. It is found naturally, in trace quantities throughout the environment – rocks, soil and the oceans, and as an introduced contaminant in the environment. Mercury never breaks down and tends to persist in the environment, cycling through land, air and water and traveling across globe. The dispersion of mercury into the environment is a major concern in the world today, especially in developing countries. Although mercury occurs naturally in the environment, human activity causes most mercury releases.
2. What are its usages through which it is released into the environment?
Mercury and its compounds have found usage in a very wide range of activities through the ages. The ability to combine as an alloy with most metals, liquidity at room temperature, effortless vaporization/freezing and electrical conductivity make mercury a very popular metal for industrial usage. Among its present 3,000 listed industrial applications, its primary uses are in chlor alkali plants, thermometers, sphygmomanometer and other measurement instruments, electrical apparatus and switches, batteries, dental amalgam and in the formulation of various compounds.
According to a recent study for the European Commission, nearly 3,700 metric tonnes of mercury is purchased around the world each year for various industrial purposes. This global mercury trade continues despite the fact that non-mercury-based alternatives are readily available for most current uses.
Coal-burning power plants are the most common source of mercury pollution. Coal is naturally contaminated with mercury, and when it is burned, the mercury simply goes up the smokestack and into the air.
Another very significant source of mercury pollution is metallic mercury, used in a number of commercial products and industrial processes. The most polluting of these uses include chemical manufacturing (chlor-alkali plants), battery manufacturing, small-scale gold mining, and production of switches, measuring devices, and other products.
3. What makes this apparently very useful metal so harmful?
Mercury is toxic by ingestion, inhalation and skin absorption with acute and chronic exposure effects including central nervous system and kidney damage. Acute exposure includes nausea, blurred vision, painful breathing, excessive salivation and pneumonitis, while chronic or longer- term exposure includes memory disturbance, hypertension, vision problems, hallucinations, tremors and personality changes.
The two properties that make mercury extremely unmanageable are bio-accumulation and bio-magnification. Because mercury can cross the blood-brain barrier, and because it can affect brain development, its effects are of special concern to pregnant or lactating women and young children.
The most common exposure routes involve food and diet. Additional exposures may be contributed through air and water, either directly or again through the route of food. The toxic effects of mercury depend on its chemical form and the route of exposure. Methyl mercury is the most toxic form. Once released, mercury persists in the environment where it circulates between air, water, sediments, soil and biota in various forms. Current emissions add to the global pool, and all of it is deposited on land and water, and re-mobilised.
4. How widely and in what sectors is it used in India?
Mercury is not mined in India. There is a thriving illegal trade in this commodity. Besides the import of virgin mercury, mercury-containing instruments, mercury compounds, electrical and electronic substances containing mercury and mercury compounds etc are also imported in large quantities.
According to the Canadian Global Emissions Interpretation Centre (CGEIC), which has published data on the spatial distribution of mercury emissions in air, India is one of the world’s mercury hotspots, with mercury being released into the air uniformly at a rate of 0.1–0.5 tonnes per year, with coastal areas having an even higher emission rate ranging between 0.5 to 2.0 tonnes per year. According to the CGEIC, anthropogenic emission of mercury is estimated to have increased in India by 27 per cent in the last decade. Clearly, mercury is a major problem and action needs to be taken now.
Estimates place release of mercury into India’s environment between 172.5 – 200 tonnes annually, and these figures exclude releases from other fossil fuels. This amount represents a grave danger for the country. The five super thermal power plants in the Singrauli area, which supply 10 per cent of India's power, are responsible for 16.85 per cent or 10 tonnes annually of total mercury pollution through power generation.
5. Are there any regulations in India that monitor or control its import and use?
There are various provisions and acts pertaining to the prevention and control of pollution and protection of the environment. Mercury finds place in some of them, but nothing that deals with it specifically. The nature and extent of threat from the deadly metal makes it a candidate for specific attention.
Some of the existing provisions that touch upon mercury are:
The Environment (Protection) Rules, 1986 also covered mercury in the standard for emission of certain industries.
The Hazardous Waste Management and Handling Rule (1989) list mercury and mercury containing waste as hazardous waste.
The Manufacture, Storage and Import of Hazardous Chemicals Rules, 1989, which also covers a few mercury compounds. The Municipal Solid Wastes (Management and Handling) Rules, 2000 specifies standard for mercury content in ground water, leachate and composts.
Mercury is included in The Workmen’s Compensation Act and The Factories Act, which mainly deal with occupation hazard, and compensation.
6. A very substantial part of mercury used in India comes through import, but why do we do not have at least restrictions on it?
Despite mercury’s toxicity and related hazards, the Free Import Policy (1997-2002) has licensed mercury as a free product for imports and “Items which do not require any license under the export and import policy have been denoted a free subject to licensing notes.” Mercury and its various compounds are all ‘free’ for import to India. Import of the mercury compounds included as hazardous waste in the Hazardous waste rules, is permitted against a license and only for the purpose of processing and reuse.
Two multilateral environmental agreements cover mercury and mercury compounds: the Basel Convention on Control of transboundary Movements of Hazardous Wastes and their Disposal; and the Rotterdam Convention on the Prior Informed Consent Procedure for Certain Chemicals and Pesticides in International Trade. These instruments regulate trade in unwanted chemicals, pesticides and hazardous wastes. However, they do not contain specific commitments to directly reduce usage and release of mercury. These loopholes are effectively exploited by multinational industries, which virtually use developing countries as dumping grounds for cheap mercury and outdated mercury technologies.
7. What is the level of awareness on mrecury exposure and hazard?
Mercury is freely available in chemical markets in India. One visit to the Tilak Bazar in Delhi and it will be clear that one can buy mercury without any problem. It is sold openly and one does not require any kind of authorization to buy this toxic metal. All the major thermometer companies, other small-scale industries using mercury, educational institutions and laboratories buy mercury from such markets.
There is general lack of awareness about mercury and its ill effects on human health among people. Not just the general public, but even people who are dealing with mercury on day-to-day basis have very little understanding of the problem. People who are trading in mercury and the labourers in these markets are hardly aware of mercury hazards.
Some studies have shown that there is low level of awareness regarding mercury in the health care sector as well. Typically in a hospital, the breakage and spill rates are very high but there are no training or awareness sessions for the staff that are handling mercury. This is also true of the most of the other industries using mercury. Certain studies have also indicated that even in educational institutions teachers, laboratory assistant and students do not know about the mercury hazard and have got no guidelines on mercury handling and disposal.
8. Any initiatives at policy level that reflect spurring of interest in the government machinery?
A draft notification was circulated by the Ministry of Environment and Forest (MoEF) in 2000 for a phased elimination of mercury from consumer products, but so far no action has been taken.
At the industrial level, the Government of India has banned the commissioning of new mercury cell based chlor-alkali plants since 1991. Central Pollution Control Board/Ministry of Environment and Forest had organised a series of industry specific interaction meeting to formulate a Charter on Corporate Responsibility for Environment Protection. (CREP).
Task forces were also constituted for overseeing the implementation of CREP. Chlor Alkali industry was also covered under the CREP programme. Under this programme, chlor-alkali plants are to phase out mercury technology by 2012 and there have been certain restrictions on mercury usage as well as discharge. But again, there has been no clarity on how the converted plants are disposing off the current mercury stocks.
In developed countries, the use of mercury in various products is either banned or regulated. No concrete initiative has however been taken by the Government of India to address the issue.