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

Expert Panel on Air Quality Standards
3.2.3 Tissue distribution and excretion
129. Most soluble forms of inhaled nickel are excreted in urine. Thus high
levels of (insoluble) nickel oxide in air give relatively low plasma and
urine concentrations but high levels in the nasal mucosa and
presumably the lung (Torjussen and Anderson, 1979; Høgetveit et al.,
1978). As nickel-induced cancer of the lung is a major cause for
concern, nickel absorbed into the blood could be considered of less
significance than that retained in the lung, although local effects may
be mediated by soluble forms.
3.3 Health effects/toxicology
3.3.1 Acute and chronic effects
130. Studies in animals have shown that chronic inflammation of the lung
and/or nasal passages follows repeated dose inhalation of a wide range
of nickel compounds. The effects seen are qualitatively similar in both
rats and mice. However, the no observed adverse effects level (NOAEL)
established in the various reported studies shows wide variation, which
in part reflects the solubility of the compound tested: more soluble
compounds show NOAEL about an order of magnitude lower than
the insoluble salts. The results of several studies have been summarised
by ASTDR (2003). In a 13 week study, nickel sulphate induced an
inflammatory response in the lungs of female rats with a NOAEL of
0.06 mg/m 3 . However, in the chronic (two year) studies conducted by
the USA National Toxicology programme (NTP, 1996 a,b,c) both rats
and mice showed limited signs of respiratory irritation/inflammation
at 0.03 mg/m 3 (the lowest dose tested), although the effect was
equivocal and confined to the few rats examined at interim sacrifice
(NTP, 1996b).
131. Apart from nickel sensitivity, which is common in the general
population, non-cancer effects in humans have been reported only in
workers involved in the production or intensive use of nickelcontaining
substances. Exposure to nickel by inhalation causes adverse
effects, including lung irritation, and pneumonia. At very high
concentrations, acute inhalation has been reported to cause severe
pulmonary irritation. A worker exposed to an estimated 382 mg/m 3 of
metallic nickel died from adult respiratory distress syndrome. Acute
inhalation effects of nickel carbonyl fall into two categories, immediate
and delayed (Defra and EA, 2002a; IEH, 2003). The immediate
response includes headache, nausea, dizziness, vomiting, insomnia and
irritability. In mild cases this resolves within a day; with more severe
exposures, typically in excess of 50 mg/m 3 , symptoms such as chest
pain, dyspnoea (shortage of breath) and oedema (fluid in the lung) can
occur 12-120 hours after exposure (EC, 2000; WHO, 1991). Severe
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