The industrialization of the modern world has led to the proliferation in our environment of many different metal compounds. Some metals, such as zinc and iron are required in trace amounts for many biological functions. Other metals such as lead and mercury have had significant toxic effects on development. There are historic examples of large scale disasters, for example the mercury poisoning of waterways in Japan (More? Mercury) Mercury poisoning (by methyl mercury) or Minamata disease had substantial neurological effects similar to Hunter Russell syndrome. In addition to their direct toxic effects, the potential reduction in fetal growth and long-term effects should also be considered (More? Fetal Origins Hypothesis) |
Environmental Heavy Metal Contamination |
The specific effects of some metals are detailed in Material Safety and Data Sheets (MSDS) available from an chemical index page that relate to developmental abnormalities. These sheets are now generally required to be supplied along with the chemical purchased from a supplier and give a standardised description of the chemical, its physical properties, handling and health effects/toxicity. There are also several internet sites that have searchable databases of MSDS information. Note that handling chemical saftey may vary from country to country.
Page Links: Introduction | Some Recent Findings | Metal Toxicity | Metal in Water | Lead | Mercury | Chromium | Lithium | Yttrium | Chemical Terms | CDC (USA) Workplace Hazards | Poison Control Centres | Australian National Drug Strategy Household Survey 1995 | Search PubMed | NHMRCrecommendations | Web Links | References | Glossary | Terms
Cecil KM, Brubaker CJ, Adler CM, Dietrich KN, Altaye M, Egelhoff JC, Wessel S, Elangovan I, Hornung R, Jarvis K, Lanphear BP. Decreased brain volume in adults with childhood lead exposure. PLoS Med. 2008 May 27;5(5):e112.
"Childhood lead exposure is associated with region-specific reductions in adult gray matter volume."
April 2008 - High blood lead levels in Australian mining community (Queensland, Mount Isa) following a Queensland Health test of 400 children. (More? ABC News - Fri Apr 11 Xstrata faces suits over lead levels | Lead)
Powell ST, Bolisetty S, Wheaton GR. Succimer therapy for congenital lead poisoning from maternal petrol sniffing. Med J Aust. 2006 Jan 16;184(2):84-5.
Gao Y, Yan CH, Tian Y, Wang Y, Xie HF, Zhou X, Yu XD, Yu XG, Tong S, Zhou QX, Shen XM. Prenatal exposure to mercury and neurobehavioral development of neonates in Zhoushan City, China. Environ Res. 2007 Nov;105(3):390-9.
Jedrychowski W, Perera F, Jankowski J, Rauh V, Flak E, Caldwell KL, Jones RL, Pac A, Lisowska-Miszczyk I. Fish consumption in pregnancy, cord blood mercury level and cognitive and psychomotor development of infants followed over the first three years of life: Krakow epidemiologic study. Environ Int. 2007 Nov;33(8):1057-62.
Marques RC, Garrofe Dórea J, Rodrigues Bastos W, de Freitas Rebelo M, de Freitas Fonseca M, Malm O. Maternal mercury exposure and neuro-motor development in breastfed infants from Porto Velho (Amazon), Brazil. Int J Hyg Environ Health. 2007 Jan;210(1):51-60.
Heavy Metals Toxicity (Table: U.S. GEOLOGICAL SURVEY CIRCULAR 1133, 1995)
In another recent study using the sea urchin embryo, Japanese researchers have identified a hierarchy of toxic effects from different heavy metals.
"Interactive toxic effects between heavy metals were investigated using a sea urchin (Anthocidaris crassispina) bioassay. An effluent from an abandoned mine showed significant inhibitory effects on embryo development as well as producing specific malformations. The effects on the embryos were reproduced by synthetic polluted seawater consisting of eight metals (manganese, lead, cadmium, nickel, zinc, chromium, iron, and copper) at the concentrations detected in the mine effluent. This indicated that the heavy metals were responsible for the effects observed. Five heavy metals were ranked in decreasing order of toxicity as follows: Cu > Zn > Pb > Fe > Mn. Among these, zinc and manganese could cause malformation of the embryos. From bioassay results using 27 combinations of heavy metals, 16 combinations including zinc could produce specific malformations, such as radialized, exo-gastrulal, and spaceship Apollo-like gastrulal embryos. Zinc was one of the elements responsible for causing malformations and its effects were intensified by the presence of the other metals, such as manganese, lead, iron, and copper." Naomasa Kobayashia and Hideo Okamurab.
References: (reference link needs repair) Naomasa Kobayashia, and Hideo Okamurab,
Saiyed H, Dewan A, Bhatnagar V, Shenoy U, Shenoy R, Rajmohan H, Patel K, Kashyap R, Kulkarni P, Rajan B, Lakkad B. Effects of heavy metals on sea urchin embryo development. Part 2. Interactive toxic effects of heavy metals in synthetic mine effluents
Chisolm JJ Jr. Poisoning from heavy metals (mercury, lead, and cadmium). Pediatr Ann. 1980 Dec;9(12):458-68. [See Related Articles]
A major dilemma is the biological difficulty of clearing heavy metals and the subsequent accumulation of these metals in the food chain mainly from the hydrologic environment.
Lead in the environment can be derived from leaded petrol, old lead piping, and other environmental sources (More? Lead MSDS).
For children aged less than 6 years of age the CDC (USA) has defined an elevated blood lead level (BLL) as >10 µg/dL, but also indicated that evidence exists for subtle effects at lower levels. (Links: CDC - Lead Poisoning Prevention Program | Blood Lead Levels in Young Children - United States and Selected States 1996-1999)
References:
Cecil KM, Brubaker CJ, Adler CM, Dietrich KN, Altaye M, Egelhoff JC, Wessel S, Elangovan I, Hornung R, Jarvis K, Lanphear BP. Decreased brain volume in adults with childhood lead exposure. PLoS Med. 2008 May 27;5(5):e112.
"Childhood lead exposure is associated with region-specific reductions in adult gray matter volume."
Powell ST, Bolisetty S, Wheaton GR. Succimer therapy for congenital lead poisoning from maternal petrol sniffing. Med J Aust. 2006 Jan 16;184(2):84-5.
Lidsky TI, Schneider JS. Lead neurotoxicity in children: basic mechanisms and clinical correlates. Brain. 2003 Jan;126(Pt 1):5-19.
Bellinger DC. Lead. Pediatrics. 2004 Apr;113(4 Suppl):1016-22.
Needleman H. Lead poisoning. Annu Rev Med. 2004;55:209-22.
Links: Lead MSDS | CDC - Lead Poisoning Prevention Program | Blood Lead Levels in Young Children - United States and Selected States 1996-1999 | AAP USA Policy statement 1998 | Medline Plus - Lead levels - blood |
Used traditionally in the felting of hats, hence "mad hatters", a more recent example of mercury's toxicity was shown in Japan.
Japan had industrial mercury poisoning of waterways by methyl mercury causing Minamata disease, which had substantial neurological effects similar to Hunter Russell syndrome. For more information on mercury the chemical, see Mercury MSDS. There has also been a movie available "Medical Study of Minamata Disease".
Australia - Food Standards Australia New Zealand (FSANZ)
"FSANZ’s Chief Scientist, Dr Marion Healy, said ‘Our investigations show that the level of mercury in most fish caught and sold in Australia is low."
"The Australian Dietary Guidelines advise eating one or two fish meals per week for good health. The good news is that FSANZ has found it is safe for all population groups to eat 2-3 serves per week of most types of fish. There are only a few types of fish, which FSANZ recommends limiting in the diet – these are billfish (swordfish / broadbill and marlin ), shark/flake, orange roughy and catfish." FSANZ updates advice on mercury in fish (Australia only) 18 March 2004
References:
Korogi Y, et al. MR findings of Minamata disease--organic mercury poisoning. J Magn Reson Imaging. 1998 Mar-Apr;8(2):308-16. [See Related Articles]
Eto K. Pathology of Minamata disease. Toxicol Pathol. 1997 Nov-Dec;25(6):614-23. [See Related Articles]
Hamada R, et al. Maternal-fetal mercury transport and fetal methylmercury poisoning. Met Ions Biol Syst. 1997;34:405-20. [See Related Articles]
Harada M. Congenital Minamata disease: intrauterine methylmercury poisoning. Teratology. 1978 Oct;18(2):285-8. [See Related Articles]
Harada M. Organic-mercury food poisoning. N Engl J Med. 1971 Apr 1;284(13):706-9. [See Related Articles]
Doi R, et al. The distribution of mercury in fish and its form of occurrence. pp. 197-221. n: Krenkel PA., ed. Heavy metals in the aquatic environment. Oxford, Pergamon. 1976 Aug 2; [See Related Articles]
Gerstner HB, et al. Selected case histories and epidemiologic examples of human mercury poisoning. Clin Toxicol. 1977 Sep;11(2):131-50. [See Related Articles]
Shephard DA. Methyl mercury poisoning in Canada. Can Med Assoc J. 1976 Mar 6;114(5):463-72. [See Related Articles]
(More? see a list of reviews and selected articles)
Hexavalent chromium (CrVI) is used in more than 50 industries and is an important heavy metal pollutant. A recent study (2005) in monkeys (Macaca radiata) has demonstrated an effect on testicular spermatogenesis, possibly by inducing free radical toxicity. If these effects also occur in humans, then spermatazoa development could also be affected, the study further suggested a supplementation of antioxidant vitamins may be beneficial to the affected subjects.
References:
Aruldhas MM, Subramanian S, Sekar P, Vengatesh G, Chandrahasan G, Govindarajulu P, Akbarsha MA. Chronic chromium exposure-induced changes in testicular histoarchitecture are associated with oxidative stress: study in a non-human primate (Macaca radiata Geoffroy). Hum Reprod. 2005 Oct;20(10):2801-13.
Lithium (Li, atomic number 3) is a soft alkali metal found in the natural environment, in industrial products (lithium batteries, some glass and ceramic products) and also is used to treat people with bipolar disorder. Lithium used as a drug, in a salt form, acts on the central nervous system as an antimanic agent to treat episodes of mania (frenzied, abnormally excited mood) associated with bipolar disorders. Lithium has been associated with fetal cardiac teratogenicity possibly by affecting Wnt/beta-catenin signaling (More? Abnormal Development - Bipolar Drugs).
References:
Chen J, Han M, Manisastry SM, Trotta P, Serrano MC, Huhta JC, Linask KK. Molecular effects of lithium exposure during mouse and chick gastrulation and subsequent valve dysmorphogenesis. Birth Defects Res A Clin Mol Teratol. 2008 Apr 16.
A therapeutic radioactive form of yttrium used in microspheres for the internal treatment of various liver cancers. As such it would be unlikely to be found in a human development situation.
Below are listed some terms which relate to a chemicals harmful effects.
A carcinogen is a chemical known or believed to cause cancer in humans. The number of known carcinogens is comparatively small, but many more chemicals are suspected to be carcinogenic.
ED50: Effective dose - the amount of material required to produce a specified effect in 50% of an animal population. (See qualification in the definition of LD50).
LD50: is the dose of a chemical which kills 50% of a sample population. In full reporting, the dose, treatment and observation period should be given. Further, LD50 and ED50 values are strictly only comparable when the age, sex and nutritional state of the animals is specified. Nevertheless, LD50 values are widely reported as a measure of the potential toxicity of chemicals.
A mutagen is an agent that changes the hereditary genetic material which is a part of every living cell. Such a mutation is probably an early step in the sequence of events that ultimately leads to the development of cancer.
TLV (Threshold Limit Value) is the maximum permissible concentration of a material, generally expressed in parts per million in air for some defined period of time (often 8 hours). These values, which may differ from country to country, are often backed up by regulation and are therefore often legally enforceable.
Reviews
Dorea JG, Donangelo CM. Early (in uterus and infant) exposure to mercury and lead. Clin Nutr. 2006 Jun;25(3):369-76.
Meagher RB, Heaton AC. Strategies for the engineered phytoremediation of toxic element pollution: mercury and arsenic. J Ind Microbiol Biotechnol. 2005 Dec;32(11-12):502-13.
Boening DW. Ecological effects, transport, and fate of mercury: a general review. Chemosphere. 2000 Jun;40(12):1335-51.
Articles
Gao Y, Yan CH, Tian Y, Wang Y, Xie HF, Zhou X, Yu XD, Yu XG, Tong S, Zhou QX, Shen XM. Prenatal exposure to mercury and neurobehavioral development of neonates in Zhoushan City, China. Environ Res. 2007 Nov;105(3):390-9.
Jedrychowski W, Perera F, Jankowski J, Rauh V, Flak E, Caldwell KL, Jones RL, Pac A, Lisowska-Miszczyk I. Fish consumption in pregnancy, cord blood mercury level and cognitive and psychomotor development of infants followed over the first three years of life: Krakow epidemiologic study. Environ Int. 2007 Nov;33(8):1057-62.
Marques RC, Garrofe Dórea J, Rodrigues Bastos W, de Freitas Rebelo M, de Freitas Fonseca M, Malm O. Maternal mercury exposure and neuro-motor development in breastfed infants from Porto Velho (Amazon), Brazil. Int J Hyg Environ Health. 2007 Jan;210(1):51-60.
Powell ST, Bolisetty S, Wheaton GR. Succimer therapy for congenital lead poisoning from maternal petrol sniffing. Med J Aust. 2006 Jan 16;184(2):84-5.
Aruldhas MM, Subramanian S, Sekar P, Vengatesh G, Chandrahasan G, Govindarajulu P, Akbarsha MA. Chronic chromium exposure-induced changes in testicular histoarchitecture are associated with oxidative stress: study in a non-human primate (Macaca radiata Geoffroy). Hum Reprod. 2005 Oct;20(10):2801-13.
Bellinger DC. Lead. Pediatrics. 2004 Apr;113(4 Suppl):1016-22.
Needleman H. Lead poisoning. Annu Rev Med. 2004;55:209-22.
Lidsky TI, Schneider JS. Lead neurotoxicity in children: basic mechanisms and clinical correlates. Brain. 2003 Jan;126(Pt 1):5-19.
Korogi Y, et al. MR findings of Minamata disease--organic mercury poisoning. J Magn Reson Imaging. 1998 Mar-Apr;8(2):308-16. [See Related Articles]
Eto K. Pathology of Minamata disease. Toxicol Pathol. 1997 Nov-Dec;25(6):614-23. [See Related Articles]
Hamada R, et al. Maternal-fetal mercury transport and fetal methylmercury poisoning. Met Ions Biol Syst. 1997;34:405-20. [See Related Articles]
Harada M. Congenital Minamata disease: intrauterine methylmercury poisoning. Teratology. 1978 Oct;18(2):285-8. [See Related Articles]
Harada M. Organic-mercury food poisoning. N Engl J Med. 1971 Apr 1;284(13):706-9. [See Related Articles]
Doi R, et al. The distribution of mercury in fish and its form of occurrence. pp. 197-221. n: Krenkel PA., ed. Heavy metals in the aquatic environment. Oxford, Pergamon. 1976 Aug 2; [See Related Articles]
Gerstner HB, et al. Selected case histories and epidemiologic examples of human mercury poisoning. Clin Toxicol. 1977 Sep;11(2):131-50. [See Related Articles]
Shephard DA. Methyl mercury poisoning in Canada. Can Med Assoc J. 1976 Mar 6;114(5):463-72. [See Related Articles]
Wood JM. Biological cycles for toxic elements in the environment. Science. 1974 Mar 15;183(129):1049-52.
Search PubMed: Search April 2008 "heavy metal contamination human development" 10 reference articles of which 1 were reviews. heavy metal contamination human development | lead and development |
The CDC (USA) has prepared a booklet that identifies the following issues:
Some workplace hazards can affect a woman's reproductive health, her ability to become pregnant, or the health of her unborn children. This document answers the following questions: What are reproductive hazards for female workers? How does the female reproductive system work? What reproductive problems might be caused by workplace exposures? How are workers and their babies exposed? How are families exposed? How can exposures be prevented?
For a more detailed worldwide list see Web Links below.
Below is an alphabetical list (by capital) of Australian state poison information centres.
Brisbane - Queensland Poisons Information Centre
Queensland Royal Children's Hospital, Herston Road, Brisbane 4029 Queensland
Director: Mr H. Miller Manager: Carol Wylie Telephone: +61 (0) 7 3636 8510
Emergency telephone: +61 (0) 7 3636 8505 or 131 126 (24 hours, accessible from anywhere in Australia)
Fax: +61 7 32521903 E-mail: poisons_info@health.qld.gov.au
Canberra - ACT Poisons Information Service
The Canberra Hospital, Yamba Drive, Garran 2605 Australian Capital Territory
Director: Mrs Morna Falkland Telephone: +61 6 2443333
Emergency telephone: 131 126 (24 hours, accessible from anywhere in Australia)
Fax: +61 6 2443334 E-mail: actpic@act.gov.au
Melbourne - Poisons Information Centre
Royal Children's Hospital, Flemington Road, Parkville, Victoria 3052
Manager: Mr Jeff Robinson Telephone: +61 3 93455333
Emergency telephone: 131 126 (24 hours, accessible from anywhere in Australia)
Fax: +61 3 93491261 E-mail: poison@crypyic.rch.unimelb.edu.au
Perth - WA Poisons Information Centre
Sir Charles Gardner Hospital, Hospital Avenue, Nedlands, Western Australia 6009
Director: Ms Cherry Alford (Pharmacist-in-Charge) Medical Director: Dr L. Murray Telephone: +61 8 9346 1943
Emergency telephone: 131 126 (24 hours, accessible from anywhere in Australia)
Fax: +61 8 9346 3493 E-mail: Cherry.Alford@health.wa.gov.au
Sydney - New South Wales Poisons Information Centre
The Children's Hospital at Westmead, Locked Bag 4001, Westmead, NSW 2145
Director: Ms J. Kirby Telephone: +61 2 9845 3599
Emergency telephone: 131 126 (Australia only), +61 2 9845 3111
Fax: +61 2 9845 3597 E-mail: judithk@chw.edu.au
Find your local poison control center by clicking on the menu below and choosing your state.
