The mercury threat is rising. As developed nations get tough with
mercury-generating industries, the developing world, and India in particular, is becoming
a hotspot for this deadly metal that plays havoc with human health
A global warning has been sounded. A recent meeting of
the Governing Council of the United Nations Environment Program (UNEP) concluded that the
global risk to humans and animals from the release of mercury into the environment is so
high that immediate international action is needed to identify groups at risk and to
reduce human-generated mercury releases.
need to raise awareness among policy-makers'
Dr R C
Srivastava, co-chairperson of the Mercury Assessment Group, UNEP, and former deputy
director of the Industrial Toxicology Research Centre, Lucknow, speaks on the dangers of
mercury pollution and the possible solutions
What is the level of mercury pollution in India?
The major sources of mercury pollution in India are chlor-alkali industries, industrial
processes in thermal power plants, steel and cement industries, coal fired power and heat
production, mercury-containing products such as thermometers, blood pressure equipment,
pesticides, dental amalgam, and waste incineration processes.
Presently, mercury consumption in the Indian chlor-alkali
sector is at least 50 times higher than the global average. This sector alone contributes
to about 40 per cent of the total mercury pollution in the country. The average specific
mercury loss from a mercury cell plant in India is 142 gm per metric tonne (MT) of caustic
soda (NaOH) produced. At this rate, the caustic chlorine sector alone emits 79 metric
tonnes of mercury every year.
Mercury contamination of water is also verging on a
crisis situation. Industrial effluents containing mercury in the range of 0.058 to 0.268
mg/l are discharged in water, whereas WHO and Indian drinking water guidelines specify
only 0.001 mg/l. Mercury levels in water near caustic chlorine firms have been reported to
be as high as 0.176 mg/l in water and approximately 596 mg/kg dry weight in soil.
The concentration of mercury in blood and hair of the
human population has been reported to be as high as 100 mg/dl and 8 mg/g respectively at
industrial sites compared to 5mg/dl and 1mg/g in unexposed populations. The concentration
of mercury in fish and other sea food consumed in certain coastal areas is reported to be
in the range of 0.03-10.82 mg/g compared to a permissible limit of 0.5 mg/g.
How can this be controlled?
There is sufficient global evidence of the adverse impacts of mercury to warrant national
and international action to reduce the risks to human health and the environment and to
develop realistic response strategies. We could start with reducing consumption of raw
materials and products that generate emissions.
We should also substitute products and processes
containing or using mercury with non-mercury alternatives. One option is end-of-pipe
technologies. We also need to look at viable mercury waste management techniques and
develop action plans to address the use and release of mercury through multi-disciplinary
We can start setting up environment quality standards and
provide incentives to promote substitution of mercury-using products and processes.
Perhaps what is most important is raising awareness among policy-makers.
How effective are current Indian
Our country lacks the regulatory infrastructure and resources needed to safeguard the
public and environment from mercury. Most European countries have formulated laws that ban
the use of mercury in products and processes. The government of India is only trying to
bring about a legislation for the phased elimination of mercury from consumer products.
Import of mercury is still legal under Indian laws. As per the Basel Convention, mercury
falls under the hazardous products category. Therefore, we should enforce stringent
regulations to prohibit import, export, sale and use of this substance.
Do you think there are viable alternatives to
the existing use of mercury in India?
Several countries have adopted mercury free alternatives in the health sector, electrical
applications, the automobile sector, in chemicals, dental amalgams and especially in the
chlor-alkali sector. Clearly, they are viable.
What should the plan of action be?
We need to regularly monitor mercury levels in air, water, soil and food materials,
generate data on the environmental release of mercury and its origin and speciation,
pathways and deposition. We need to conduct studies on exposed populations, come up with
awareness programmes for the general public and establish a task force to coordinate and
implement the mercury action plan and poison information centres to provide
Mercury, a heavy metal, is used in a number of industrial
applications and products. It is a highly mobile element and cannot be broken down into
harmless components. When it combines with carbon, it forms organic mercury compounds such
as methyl mercury, which is the most common form of mercury found in the environment. This
methyl mercury passes into the air, soil and the food chain, mostly through aquatic
animals. It can then become a considerable health risk.
The Council was responding to a December 2002 report by
the Global Mercury Assessment Working Group, instituted by the UNEP to undertake a global
assessment of mercury and mercury compounds and their impact on the environment. The
report says that stricter regulations and a reduction in the use of mercury in developed
nations have led to an untoward increase in the use of cheap mercury and outdated
technologies in the developing world.
Presently, India is the second-largest user of mercury in
the world (170190 tonnes a year) after the US (372 tonnes annually). While the US
has an effective retrieval system and strict norms, India hardly has any regulation worth
speaking of. Slowly, but surely, mercury pollution is the crisis of the near-future. The
Indian governments track record is indeed very poor. There are no norms for
controlling the use of mercury in various products. A draft notification was issued by the
Ministry of Environment and Forests in 2000 for a phased elimination of mercury from
consumer products, but so far no action has been taken on it. The government may have
banned the setting-up of new mercury-based caustic soda plants, but it does not have any
concrete plans to phase out the existing ones, which are causing widespread mercury
Furthermore, 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 worlds mercury hotspots, with mercury
being released into the air uniformly at a rate of 0.10.5 tonnes per year, with
coastal areas having an even higher emission rate ranging between 0.5 to 2 tonnes/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.
Use and abuse
There are two sources from which mercury can be mobilised into the environment
natural and anthropogenic or human-generated. Anthropogenic emission, again, can be of two
kinds intentional and unintentional. The release of mercury into the environment
through industrial processes and products is generally intentional, while mobilisation of
mercury impurities in fossil fuels particularly coal, and to a lesser extent gas
and oil and other extracted, treated and recycled minerals is mostly unintentional.
It is the anthropogenic emission of mercury that is the cause for greatest concern.
What is the answer to this looming crisis? It is possible
to replace mercury with other available industrial raw
materials, but before that, what is needed is immediate and effective policy changes,
before it is too late.