Guidelines for Metals and Metalloids in Ambient ... - ARCHIVE: Defra

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Expert Panel on Air Quality Standards 5.3.2 Chronic and sub-chronic effects 5.3.2.1 Animal studies 257. In studies involving rats fed up to 1000 times the daily human intake of chromium no toxic effects have been reported (Anderson, 1997) although decreased testicular enzyme activity has been noted (von Burg and Liu, 1993). 258. Following inhalation, immune system effects have been observed in animals exposed to both trivalent and hexavalent chromium. Responses included increased macrophage activity, total serum immunoglobulin content and antibody response (von Burg and Liu, 1993). 5.3.2.2 Non-malignant effects 259. Hexavalent chromium is a dermal irritant and sensitiser that can induce and provoke a delayed-type allergic contact dermatitis; sensitisation is identified through patch testing of the skin. These outcomes are not uncommon in several occupational settings including chrome-plating, leather tanning, and work involving repeated skin contact with wet cement. It is estimated that 0.08% of the USA population is sensitised in this way (Proctor et al., 1998). 260. Estimates of the dermal dose required to elicit an allergic response in sensitised individuals vary between from 0.09 and 12.5 µg/cm 2 (Scott and Proctor, 1997; Nethercott et al., 1994). 261. Trivalent chromium may also act as a dermal sensitising agent but appears to be less potent in this respect than Cr(VI). 262. Respiratory sensitisation to Cr(VI) may also occur in response to workplace exposures (Keskinen et al., 1980; Moller et al., 1986) but is probably rare. There is no published information on the threshold concentrations of airborne chromium necessary to induce respiratory sensitisation or to provoke symptoms in those who are sensitised. 263. Chronic exposures to chromium fumes have been related to an excess of deaths from non-malignant respiratory disease in UK (Sorahan et al., 1987; Davies et al., 1991) and USA (Taylor, 1966) employees in the chromate production or electroplating industries. These associations are believed to relate directly to chromium exposures – rather than to confounding, current or past exposures to other metals such as nickel – but the effects of cigarette smoking have not been examined in detail. No reliable exposure estimates are available. In a chromate production plant in the USA at which atmospheric concentrations of Cr(VI) 90
Chromium occasionally reached levels of 289 µg/m 3 , high cumulative exposure was not associated with an increased risk of chronic bronchitis, emphysema, shortness of breath, or chronic cough (Pastides et al., 1994). Among a group of chrome-plating workers in Sweden, with a median exposure of 2.5 years, transient reductions in lung volumes have been associated with exposures to Cr(VI) above 2 µg/m 3 (Lindberg and Hedenstierna, 1983). Among 106 workers producing Cr(III) oxide and sulphate compounds – with estimated exposures to Cr(III) of 1.99 mg/m 3 there was no evidence of current respiratory disease (Korallus et al., 1974). Two hundred and twenty one stainless steel production workers with median exposures to Cr(VI) of 0.0005 µg/m 3 and to Cr(III) of 0.022 µg/m 3 (similar to those in ambient air) had similar lung function and chest X-ray findings to an unexposed control group (Huvinen et al., 1996). 264. Chronic rhinitis, nasal ulceration and perforation of the nasal septum have each been described in occupationally-exposed populations. There was a high incidence of these outcomes in an Italian population of chromate production workers with measured exposures to Cr(VI) of 10 µg/m 3 (Sassi, 1956). In the Swedish chrome-platers described above, clinical evidence of nasal disease was evident among employees with mean exposure levels to Cr(VI) of 2–200 µg/m 3 . No significant nasal effects were observed in workers exposed at peak levels of 0.2-1 µg/m 3 . It is suggested that nasal adverse effects may in part be attributable to chromium salts being applied directly from contaminated fingers. 265. Sub-clinical evidence suggestive of renal damage has been described in some populations with occupational exposure to chromium compounds. In 43 men working in the chromate and dichromate production industry, where occupational exposures to Cr(VI) were between 50 and 1000 µg/m 3 there were increased urinary levels of small proteins (retinol binding protein and tubular antigens) (Franchini and Mutti, 1988). Studies of populations with lower exposures have found equivocal or no adverse renal effects. Urinalysis of samples from Italian chromate production workers with estimated exposures of 10 µg/m 3 found no abnormalities (Sassi, 1956). Elevated urinary levels of ß2-microglobulin were observed in chrome platers with personal exposures over about five years to Cr(VI) of 4 µg/m 3 (Lindberg and Vesterberg, 1983; Liu et al., 1998); but not in retired platers suggesting a reversible effect (Lindberg and Vesterberg, 1983). Occupational exposure to Cr(III) or Cr(0) does not appear to be associated with adverse renal effects. 266. In addition to allergic sensitisation, direct skin contact with chromium salts can give rise to irritant dermatitis and skin ulceration. These have been related to airborne concentrations of chromium in the workplace but it is difficult to disentangle these from dermal exposures. 91
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Department for Environment, Food an
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Department for Environment, Food an
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Contents Contents Terms of Referenc
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3.5 Justification for air quality g
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Terms of Reference The Expert Panel
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Dr Alison Searl BSc, MSc, PhD Insti
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Acknowledgments We thank the follow
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Expert Panel on Air Quality Standar
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Page 56 and 57: Expert Panel on Air Quality Standar
Page 99 and 100: Chapter 5 Chromium 5.1 Background 5
Page 101 and 102: Chromium stations, industry and for
Page 103 and 104: Chromium 245. Occupational exposure
Page 105: Chromium 5.2.3 Tissue distribution
Page 109 and 110: Chromium 5.3.4.2 Human studies 272.
Page 111 and 112: Chromium 282. The WHO (2000) classi
Page 113 and 114: Chromium 5.5. Justification for air
Page 115 and 116: Chromium 5.6. Recommendation 304. 0
Page 117 and 118: Chromium HSE (2002). EH64 Summary C
Page 119 and 120: Chromium Nethercott, J., Paustenbac
Page 121 and 122: Chromium Von Burg, R. and Liu, D. (
Page 123 and 124: Abbreviations ACGIH American Confer
Page 125 and 126: Glossary Acute toxicity / effects A
Page 127 and 128: Glossary Epidemiology Epithelium Fe
Page 129 and 130: Glossary Metalloid Mucocilliary tra
Page 131 and 132: Glossary Threshold Limit Values (TL
Page 133 and 134: Appendix 1 Setting air quality stan
Page 135 and 136: Appendix 1 hours per week for a 40
Page 137 and 138: Appendix 1 arrive at a single conce
Page 139: ISBN 978-0-85521-185-1 £10.00 Prod
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