Science in Society Archive

Mercury A Growing Scourge

Mercury pollution is a growing global menace. Prof. Joe Cummins calls for UN regulation

Mercury pollution is a growing problem worldwide, especially for communities in the orient and the arctic. Its impact has also been felt in the gold fields of South American jungles. The Centre for Science and Environment India (CSE) has put out a powerful indictment of the problem in their website [1]. The website includes evidence that industry consumes and emit mercury at an alarming rate under lax regulation, that India is a global mercury hot spot and there are significant health impacts. India imports over 250 tonnes of mercury each year and 220 tonnes leak into the environment. The main culprits are outdated chlor-alkali plants and thermal power plants.

CSE proposes that a reduction in mercury pollution can be achieved in three ways: switchover of mercury-using products and processes to non-mercury alternatives, control of mercury release through end-of-pipe techniques, and mercury waste management.

The medical journal Lancet recently summarized concerns over mercury pollution in India focusing on medical waste from thermometers and blood pressure monitors of which India produces over 10 million each year. The wastes filter into water and mercury is released to the air during incineration [2].

Mercury is released to waterways in the form of ionic mercury while atmospheric releases are about half elemental and half ionic mercury [3]. In 1995, Asia contributed 50% of total global atmospheric emission of mercury, while Europe and North America combined contributes less than 25% [4]. Atmospheric mercury is circulated by wind and deposited in the form of elemental and ionic mercury, which is converted to alkyl (primarily methyl) mercury that bio-accumulates and magnifies through the food chain. High levels of methyl mercury have been encountered in the diets of the residents of coastal India [5].

The impact of mercury pollution has been studied a great deal. The city of Minimata in southern Japan was subject to widespread methyl mercury poisoning related to chlor-alkali plant emissions from 1950 to 1969. The resulting epidemic of mercury poisoning was called Minimata disease, it was the first record of the impact of methyl mercury poisoning in humans. The impact on the central nervous system and reproduction was severe, and long term follow-up of the affected population showed that the impact was persistent and included a declining male birth ratio associated with increased fetal male abortion [6].

Prenatal exposure of children to their mother’s dietary intake of methyl mercury in pilot whale meat in the arctic Faroe Islands was associated with both nerve and blood defects at even low levels of mercury pollution, and similar results were reported for the island Maedera off the coast of Morocco, where mercury accumulated in the deep sea fish black scabbard [7].

Gold mining operations on the Philippine island Mindanoa caused extensive pollution of waterways and methyl mercury pollution of fish eaten by residents. Children suffered nerve damage and were underweight [8]. Children and adults in the Quebec arctic, whose diets include marine mammals polluted with methyl mercury, showed blood mercury levels above those producing subtle neurodevelopmental defects in other populations [9,10].

Clearly, the effects of mercury pollution are global in nature and permeate areas where there is no industrial activity. Mercury pollution even at very low levels produces subtle defects.

The United Nations Environmental program has been slow to act on the global nature of mercury pollution. The United Nations consideration of atmospherics aspects of mercury pollution seems to have ignored the need to identify the sources of atmospheric mercury but instead allowed the problem to be ascribed to the innocent victims of the deposition.

The United Nations will have to deal urgently with the trans boundary mercury pollution and implement programs for remediation in the polluted countries.

Article first published 28/11/03


  1. Mercury Menace, Centre for Science and Environment India (CSE). Oct. 31,2003
  2. Sharma D. Concern over mercury pollution in India. Lancet 2003, 362, 1050.
  3. Carpi A. Mercury from combustion sources: A review of the chemical species emitted and their transport in the atmosphere. Water, Air and Soil Pollution 1997, 98,241-54.
  4. Pacyna E and Pacyna J. Global emission of mercury from anthropogenic sources in 1995. Water, Air and Soil Pollution 2002, 137,149-65
  5. Pandit G, Tripathi P and Krishnamoorthy T. Intake of methyl mercury by the population in Mumbai, India. Sci Total Environ 1997, 205, 267-70.
  6. Sakamoto M, Nakano A and Akagi H. Declining Minimata male birth ratio associated with male fetal death due to heavy methyl mercury pollution. Environmental Research Section A 2001, 87,92-8
  7. NIEHS News. More evidence of mercury effects in children. Envir Health Perspectives 1999, 107,1-5
  8. Akagi H, Castillo H, Cotes-Maramba N, Fransico-Rivera A and Timbang T. Health assessment for mercury exposure among schoolchildren residing near a gold processing and refining in Apokon, Tagum, Davao del Norte, Philippines. Sci Total Environ 2000, 259,31-43
  9. Muckle G, Ayotte P, Dewailly E, Jacobson S and Jacobson L. Prenatal exposure of northern Quebec Inuit infants to environmental contaminants. Envir Health Perspect 2001,109,1291-9
  10. Dewailly E, Ayotte P, Bruneau S, Lebel G, Levallois P and Weber J. Exposure of the Inuit population of Nunavik (Arctic Quebec) to lead and mercury. Arch. Environ Health 2001, 56,350-7

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