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Go J, Farhat N, Leingartner K, Insel EI, Momoli F, Carrier R, Krewski D. Review of epidemiological and toxicological studies on health effects from ingestion of asbestos in drinking water. Crit Rev Toxicol 2024:1-39. [PMID: 39436319 DOI: 10.1080/10408444.2024.2399840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2024] [Revised: 08/19/2024] [Accepted: 08/20/2024] [Indexed: 10/23/2024]
Abstract
Asbestos is a group of naturally occurring fibrous minerals that were commonly used in the construction of cement pipes for drinking water distribution systems. These pipes deteriorate and can release asbestos fibers into drinking water, raising concerns about potential risk to human health. The objective of this work was to synthesize human, animal, and in vitro evidence on potential health risks due to ingested asbestos in drinking water and evaluate the weight of evidence (WoE) of human health risk. A systematic review of epidemiological evidence was conducted, along with critical review of animal and in vitro evidence, followed by WoE evaluation that integrated human, animal, and in vitro evidence. The systematic review included 17 human studies with health outcomes mostly related to various cancer sites, with the majority focusing on the gastrointestinal system. The WoE evaluation resulted in very low levels of confidence or insufficient evidence of a health effect for cancers in 15 organ systems and for three non-cancer endpoints. While eight studies reported possible associations with stomach cancer in males, few high-quality studies were available to verify a causal relationship. Based on high-quality animal studies, an increased risk for cancer or non-cancer endpoints was not supported, aligning with findings from human studies. Overall, the currently available body of evidence is insufficient to establish a clear link between asbestos contamination in drinking water and adverse health effects. Due to the lack of both high-quality epidemiological studies and a validated kinetic model for ingested asbestos, additional research on this association is warranted.
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Affiliation(s)
- Jennifer Go
- Chemical and Product Safety, Risk Sciences International, Ottawa, ON, Canada
- School of Epidemiology and Public Health, University of Ottawa, Ottawa, ON, Canada
| | - Nawal Farhat
- Chemical and Product Safety, Risk Sciences International, Ottawa, ON, Canada
- School of Mathematics and Statistics, Carleton University, Ottawa, ON, Canada
| | | | - Elvin Iscan Insel
- Chemical and Product Safety, Risk Sciences International, Ottawa, ON, Canada
| | - Franco Momoli
- Chemical and Product Safety, Risk Sciences International, Ottawa, ON, Canada
- School of Epidemiology and Public Health, University of Ottawa, Ottawa, ON, Canada
| | - Richard Carrier
- Water and Air Quality Bureau, Health Canada, Ottawa, ON, Canada
| | - Daniel Krewski
- Chemical and Product Safety, Risk Sciences International, Ottawa, ON, Canada
- School of Epidemiology and Public Health, University of Ottawa, Ottawa, ON, Canada
- School of Mathematics and Statistics, Carleton University, Ottawa, ON, Canada
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Montizaan GK, Knaap AG, Van der Heijden CA. Asbestos: toxicology and risk assessment for the general population in The Netherlands. Food Chem Toxicol 1989; 27:53-63. [PMID: 2649425 DOI: 10.1016/0278-6915(89)90093-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Within the scope of the preparation of Integrated Criteria Documents for priority compounds in The Netherlands, the possible health effects of oral and inhalatory exposure to asbestos for the general population were evaluated. It was concluded from the results of experiments in animals that exposure to asbestos by the oral route is not carcinogenic and is not expected to present a health risk to the general population. Inhaled asbestos, however, is distinctly carcinogenic to man, giving rise to lung tumours, and mesotheliomas of the pleura and peritoneum. Chrysotile asbestos appears to be less potent in inducing mesotheliomas than the amphiboles, but all types of asbestos appear to have a similar potency for inducing lung cancer. The risk of mesothelioma is not expected to be influenced by smoking, whereas the risk of lung cancer is expected to be ten times higher in smokers than in non-smokers exposed to the same asbestos concentrations. Risk-assessment models for the inhalatory route, for the general population, are based on linear non-threshold extrapolation of occupational exposure to much lower environmental concentrations. These models give only a rough approximation of the risk of environmental exposure to asbestos. In accordance with the Air Quality Guidelines of the World Health Organization (World Health Organization, 1987), it was estimated that an extra risk of lung cancer of one in 10(6) (in the general population, with 30% smokers) may be presented by lifetime exposure to asbestos fibres longer than 5 microns, measured by electron microscopy, at concentrations of 100-1000/m3. It was further estimated that an extra risk of mesothelioma of one in 10(6) may be presented by lifetime exposure to 10-100 amphibole fibres/m3 or to a range of 100-10000 chrysotile fibres/m3 (fibres longer than 5 microns). From the current asbestos concentrations, the risk of mesothelioma for the general population in The Netherlands appears to be negligible; the extra risk of lung cancer is expected to be higher than 1 in 10(6) near asbestos sources, whereas it appears to be negligible in background areas and in most large cities and industrial areas. However, it must be borne in mind that the validity of the risk figures given is difficult to judge.
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Affiliation(s)
- G K Montizaan
- National Institute of Public Health and Environmental Protection, Bilthoven, The Netherlands
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Meek ME, Grasso P. An investigation of the penetration of ingested asbestos into the normal and abnormal intestinal mucosa of the rat. Food Chem Toxicol 1983; 21:193-200. [PMID: 6682082 DOI: 10.1016/0278-6915(83)90236-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
To characterize the tissue response associated with the presence of asbestos fibres in the gastro-intestinal wall, duodenal tissues of Wistar rats were examined by light microscopy following injection of a suspension containing amosite fibres into the wall of the duodenum. Intestinal tissues were also examined by light microscopy following oral administration of amosite for 5 days to healthy animals and for up to 7 days to animals with induced gastro-intestinal ulcers. Injection of amosite into the wall of the gastro-intestinal tract resulted in granulomatous lesions characterized by large numbers of macrophages containing crystals with the polarizing characteristics of amosite fibres. Examination by polarizing light microscopy following ingestion of asbestos revealed no such lesions or other histopathological abnormalities in the gut wall of the healthy animals and no intracellular fibres were observed in the animals with ulcers. Light microscopy, therefore, yielded no pathological evidence of widespread transmigration of asbestos from the gastro-intestinal tract of rats, even under conditions of mucosal loss. Further studies involving analysis by electron microscopy are under way.
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Gulumian M, Sardianos F, Kilroe-Smith T, Ockerse G. Lipid peroxidation in microsomes induced by crocidolite fibres. Chem Biol Interact 1983; 44:111-8. [PMID: 6303608 DOI: 10.1016/0009-2797(83)90133-3] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
When rat liver and lung microsomes were incubated with crocidolite fibres, a substantial increase in lipid peroxidation was observed. Increasing concentrations of this fibre in the incubation mixture, produced a concomitant induction in microsomal lipid peroxidation. This increase was very rapid as the reaction was almost complete within 10 min. The ability of these fibres to induce this process after a short period of incubation seems to be due to their binding to the microsomes. The iron present in the structure of crocidolite is thought to be responsible for catalysing the peroxidation. The formation of free radicals by asbestos and possible pathological sequelae are discussed.
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Huang SL, Saggioro D, Michelmann H, Malling HV. Genetic effects of crocidolite asbestos in Chinese hamster lung cells. Mutat Res 1978; 57:225-32. [PMID: 661841 DOI: 10.1016/0027-5107(78)90272-5] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Chinese hamster lung cells cultured in the presence of crocidolite asbestos displayed inhibition of cell growth. Cell death was directly associated with the phagocytosis of larger fibres as observed with the aid of trypan blue. Water soluble components of crocidolite did not appear to inhibit cell growth. Chromosomal aberrations were induced by the asbestos. The aberrations were confined mainly to structural aberrations--breaks and fragments. Electron-microscopic preparation indicated that asbestos was readily contained in phagosomes. Phagocytosed asbestos appeared to be a weak mutagen in its ability to induce gene mutation at the hypoxanthine-guanine phosphoribosyl transferase locus.
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