Elsevier

Environment International

Volume 33, Issue 1, January 2007, Pages 108-121
Environment International

Review Article
Environmental mercury contamination in China: Sources and impacts

https://doi.org/10.1016/j.envint.2006.06.022Get rights and content

Abstract

This review article focused on the current status of mercury (Hg) contamination in different ecological compartments in China, and their possible environmental and health impacts, focusing on some major cities. Mercury emission from non-ferrous metals smelting (especially zinc smelting), coal combustion and miscellaneous activities (of which battery and fluorescent lamp production and cement production are the largest), contributed about 45%, 38% and 17%, respectively, to the total Hg emission based on the data of 1999. Mercury contamination is widespread in different ecological compartments such as atmosphere, soil and water. There is evidence showing bioaccumulation and biomagnification of Hg in aquatic food chains, with higher concentrations detected in carnivorous fish. In terms of human exposure to Hg, fish consumption is the major exposure pathway for residents living in coastal cities such as Hong Kong, but inhalation may be another major source, affecting human health in areas with severe atmospheric Hg, such as Guiyang City (Guizhou Province). The first case study indicated that after closure of the acetic acid plant 20 years at Songyuan City (Jilin Province), 16.7% of residents' hair still contained Hg concentration in excess of 1 mg/kg (the reference dosage value, RfD set by USEPA). The second case study indicated that the male residents of Hong Kong who consumed more than four or more meals of fish per week tended to contain higher Hg in their hair, which was linked to their subfertility. There is also increasing evidence showing that skin disorders and autism in Hong Kong children are related to their high Hg body loadings (hair, blood and urine), through prenatal methyl Hg exposure. There seems to be an urgent need to identify the sources of Hg, speciation and concentrations in different ecological compartments, which may lead to high body loadings in human beings. Adverse health effects of residents living in places with a higher background level of Hg, due to long-term exposure to chronic levels of Hg through oral intake should not be overlooked.

Introduction

Mercury (Hg) is one of the most toxic heavy metals commonly found in the global environment including lithosphere, hydrosphere, atmosphere and biosphere. A series of complex chemical transformations allows the three-oxidation states of Hg to cycle in the environment (Barbosa et al., 2001). Most of the Hg encountered in all environmental media (water/soil/sediments/biota) is in the form of inorganic mercuric salts and organomercurics, with the sole exception of atmosphere. The mercuric salts HgCl2, Hg(OH)2 and HgS are the prevalent forms existing in the environment and CH3HgCl and CH3HgOH are main forms of organic compounds, together with other organomercurics (i.e., dimethylmercury and phenylmercury) existing in small fractions (USEPA, 1997a).

Natural, anthropogenic and re-emitted sources are the three major sources of Hg emissions (USEPA, 1997b), whereas the most important anthropogenic sources of Hg pollution in the environment are urban discharges, agricultural materials, mining and combustion and industrial discharges. Atmospheric deposition is an important pathway for Hg deposition into the environment. The amount of Hg in the atmosphere is estimated to have increased as much as ten-fold since the beginning of the industrial revolution (USEPA, 2003); moreover, it was indicated that the total amount of Hg emission into atmosphere from natural sources, including volcanoes, soils, forests, lakes and open oceans, was 2000 t annually in the world (Mason et al., 1994), while that amount from anthropogenic sources, mainly due to combustion and waste incineration, was 2000–2200 t annually (Seigneur et al., 2004) and the amount re-emitted of previously deposited Hg was about 2000 t annually (Bergan et al., 1999). Emission inventories indicate that Asian Hg sources account for more than 50% of the global anthropogenic total Hg (Jaffe et al., 2005). In the next few decades, a significant increase in anthropogenic Hg emissions in Asia is likely, owing to rapid economic and industrial development, unless drastic measures are taken (Wong et al., in press). This is especially so for China, as she has become a major player in steel production, which grew considerably to 22.8% (220 Mt) of the world's output in 2003 compared to 12.3% in 1993 (Sweeny, 2004), and also a consumer of large quantities of coal (1270 Mt), with 26.2% of the world's total coal consumption in 2001, a 23% increase from 1990 (USEIA, 2005).

This article is an attempt to review the current status of the major sources of Hg emissions in China, their fates in different environmental matrixes, and environmental and health effects. Two case studies are cited to illustrate the potential human health impacts: one deals with the Hg concentrations in residents of Songyuan City (Jilin Province), northeast China, 20 years after the closure of an acetic acid plant, and the other with subfertility in men and skin disorder and autism in children due to fish consumption in Hong Kong, south China.

Section snippets

Sources of Hg contamination in Chinese cities

It has been estimated that the amount of total Hg emissions were 536 (± 236) t from China in 1999. Mercury emission from non-ferrous metals smelting, coal combustion, and miscellaneous activities, of which battery and fluorescent lamp production and cement production are the largest, contributed about 45%, 38% and 17%, respectively, to the total Hg emission (Streets et al., 2005).

Mercury levels in air

Elemental Hg (Hg0) and divalent Hg (Hg(II)) are the major forms existing in atmosphere. Moreover, the latter is composed of gaseous divalent Hg (Hg2+) and particulate divalent Hg (Hgp) (USEPA, 1997b). Compared with a relatively much shorter atmospheric lifetime of hours to divalent Hg species, the average residence time of Hg0 in atmosphere is a longer period of 0.5–2 years, which allows Hg0 to transport to far distances in the atmosphere and contributes to the Hg global cycling (USEPA, 1997b).

Mercury exposure pathways

Inhalation, consumption of water, fish and other food items and ingestion of soil are common human Hg exposure routes, with Hg usually in the inorganic forms and of very low concentration. After inhalation of Hg by human beings, elemental Hg vapor rapidly diffuses through the alveolar membrane and is absorbed through the lungs. Exposure to more than 100,000–200,000 ng/m3 of elemental Hg vapor for a few hours can cause acute chemical bronchiolitis and pneumonitis, and the threshold limit of

Northern China, 20 years after closure of an acetic acid plant

Songhua River in Jilin Province was heavily polluted by Hg due to an acetic acid plant in the 1960s. Ninety-two percent of fish collected from the river contained Hg in excess of 0.4 mg/kg, resulting in 13.5 mg/kg (highest value 118.8 mg/kg) of Hg in fishermen's hair. MeHg poisoning due to overconsumption of contaminated fish was noted in some fishermen. Drainage of wastewater from the plant was terminated in 1982 (Wu, 1984). A comprehensive survey was conducted 20 years later (2002–2005) to

Conclusion

Metal smelting (especially Zn smelting) and coal combustion (especially industrial and power plants) are the two major sources for Hg contamination in the environment. The limited amount of data available indicated Hg contamination existed in different ecological compartments in China. Fish consumption is the main exposure pathway of Hg to certain populations, especially coastal populations (such as Hong Kong) that consume a larger amount of fish. In addition, due to the serious Hg

Acknowledgements

Financial support from the Group Research, Central Allocation, Research Grants Council of the University Grants Committee of Hong Kong is gratefully acknowledged. The authors thank Ms. Ursula Absalom and Dr. Leung for improving the paper.

References (156)

  • T.P. Dupre et al.

    Variation of mercury concentration in fish taken from Lake Boeuf, southeastern Louisiana

    Microchem J

    (1999)
  • F.M. Fang et al.

    Atmospheric particulate mercury content concentration and its dry deposition flux in Changchun City, China

    Sci Total Environ

    (2001)
  • X.B. Feng et al.

    Total gaseous mercury in the atmosphere of Guiyang, PR China

    Sci Total Environ

    (2003)
  • V.M. Fthenakis

    Life cycle impact analysis of cadmium in CdTePV production

    Renew Sustain Energy Rev

    (2004)
  • J.E. Gray et al.

    Distribution, speciation, and transport of mercury in stream-sediment, stream-water, and fish collected near abandoned mercury mines in southwestern Alaska, USA

    Sci Total Environ

    (2000)
  • L.D. Hylander et al.

    500 years of mercury production: global annual inventory by region until 2000 and associated emissions

    Sci Total Environ

    (2003)
  • D. Jaffe et al.

    Export of atmospheric mercury from Asia

    Atmos Environ

    (2005)
  • R.R. Jensen et al.

    Artificial neural network-based estimation of mercury speciation in combustion flue gases

    Fuel Process Technol

    (2004)
  • N.L. Judd et al.

    Consideration of cultural and lifestyle factors in defining susceptible populations for environmental disease

    Toxicology

    (2004)
  • R. Lilis et al.

    Acute mercury poisoning with severe chronic pulmonary manifestations

    Chest

    (1985)
  • A.P.S. Lima et al.

    Mercury and selenium concentrations in fish samples from Cachoeira do Piria Municipality, Para State, Brazil

    Environ Res

    (2005)
  • A. Lindberg et al.

    Exposure to methylmercury in non-fish-eating people in Sweden

    Environ Res

    (2004)
  • S.L. Liu et al.

    Atmospheric mercury monitoring survey in Beijing, China

    Chemosphere

    (2002)
  • K.R. Mahaffey

    Fish and shellfish as dietary sources of methylmercury and the omega-3 fatty acids, eicosahexaenoic acid and decosahexaenoic acid: risks and benefits

    Environ Res

    (2004)
  • R.P. Mason et al.

    The biogeochemical cycling of elemental mercury: anthropogenic influences

    Geochim Cosmochim Acta

    (1994)
  • E. Mendez et al.

    Total mercury content-Fish weight relationship in swordfish (Xiphias gladius) caught in the Southwest Atlantic Ocean

    J Food Compos Anal

    (2001)
  • F. Riget et al.

    Lead, cadmium, mercury and selenium in Greenland marine biota and sediments during AMAP phase 1

    Sci Total Environ

    (2000)
  • B. Rowens et al.

    Respiratory failure and death following acute inhalation of mercury vapor. A clinical and histological perspective

    Chest

    (1991)
  • A.C. Barbosa et al.

    Mercury contamination in the Brazilian Amazon: environmental and occupational aspects

    Water Air Soil Pollut

    (1995)
  • A.C. Barbosa et al.

    Hair mercury speciation as a function of gender, age, and body mass index in inhabitants of the Negro River Basin, Amazon, Brazil

    Arch Environ Contam Toxicol

    (2001)
  • K.A. Bjőrnberg et al.

    Methyl mercury and inorganic mercury in Swedish pregnant women and in cord blood: influence of fish consumption

    Environ Health Perspect

    (2003)
  • K.A. Bjőrnberg et al.

    Transport of methylmercury and inorganic mercury to the fetus and breast-fed infant

    Environ Health Perspect

    (2005)
  • J. Bradstreet et al.

    A case-control study of mercury burden in children with autistic spectrum disorders

    J Am Phys Surg

    (2003)
  • C. Brosset et al.

    Mercury in precipitation and ambient air: a new scenario

    Water Air Soil Pollut

    (1991)
  • J. Burger et al.

    Mercury in commercial fish: optimizing individual choices to reduce risk

    Environ Health Perspect

    (2005)
  • CCME (Canadian Council of Ministers of the Environment). The national contaminated sites remediation program: Annual...
  • Y.Z. Chen

    The detection of amount of residual mercury in market meat egg and milk

    J Sichuan Agricul Univer

    (1990)
  • H.M. Chen et al.

    Heavy metal pollution in soils in China: status and countermeasures

    AMBIO

    (1999)
  • Y.C. Chen et al.

    Comparison of the metal concentration in muscle and liver tissues of fishes from the Erren River, southwestern Taiwan, after the restoration in 2000

    J Food Drug Anal

    (2004)
  • Z.Q. Chen et al.

    The investigation and assessment on the hair mercury concentrations in pregnant and infant in the area of Luzhou

    J Luzhou Med Coll

    (2004)
  • CNEPA (China National Environmental Protection Agent)
  • CNEPA (China National Environmental Protection Agent). Environmental quality standard for surface water. GHZB 1-1999;...
  • P. Crandjean et al.

    Cognitive deficit in 7-year old children with prenatal exposure to methylmercury

    Neutotox Teretol

    (1997)
  • R. Dabeka et al.

    Survey of total mercury in some edible fish and shellfish species collected in Canada in 2002

    Food Addit Contam

    (2004)
  • D.S. Da Silva et al.

    Trophic structure and bioaccumulation of mercury in fish of three natural lakes of the Brazilian Amazon

    Water Air Soil Pollut

    (2005)
  • F.K. Dong

    Mercury elimination from the smoke and gas in acid made procedure using erect pot

    Sulph Acid Indus

    (1993)
  • G.L. Dong

    Technology on mercury elimination in Northwestern Zinc Smelting Plant in China

    Sulph Acid Indus

    (1997)
  • X.Q. Duan et al.

    The pollution station of air particulate mercury in Lanzhou metropolitan, China

    Environ Monit Technol

    (1995)
  • L. Dusek et al.

    Bioaccumulation of mercury in muscle tissue of fish in the Elbe River (Czech Republic): multispecies monitoring study 1991–1996

    J Am Coll Cardiol

    (2005)
  • ECP (EarthTrends Country Profiles). Coastal and marine ecosystems—Hong Kong. 2000....
  • Cited by (388)

    View all citing articles on Scopus

    “Capsule”: mercury contamination in different ecological compartments in China has potential adverse health effect to populations with high fish consumption and people living near power plants.

    View full text