Lead Toxicity in Mute Swans

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MATERIALS AND METHODS
Collection and analyses of samples
Mute swan corpses were collected as part of a major study on the
sources of lead contamination in this species in Ireland (see
O'Halloran et al., (B) in press).
Cause of death was determined, birds
were weighed, and samples of liver, kidney, pancreas, heart, breast and
gizzard muscle were taken for analysis.
Blood and feather samples were
taken from live uniquely ringed Mute swans at Cork Lough in S.W.
Ireland and from live birds which had been involved in collisions.
Blood and tissue lead levels were determined following acid
digestion with 10% nitric acid (Aristar grade).
Lead estimations were
carried out using an SP 192 atomic absorption spectrophotometer with a
flameless atomiser attachment and a wavelenth of 217 nm (O'Halloran and
Duggan, 1984).
Primary covert feathers were removed from live swans
and the age of feathers ( i.e. whether the bird was at a moult or
premoult stage) were noted.
Each feather was washed three times in
acetone and then in de-ionised water to remove surface contamination
(Hiderbrand and White, 1974).
Specimens were then dried to constant
weight, reweighed and digested as for tissues.
Haemoglobin (Hb) was determined by converting all haem species to
alkaline haematin using a non-ionic detergent (O'Halloran et al.,
1987b).
Haematocrit (Haem) was calculated following
micro-centrifugation at 12 000 X G.
Mean cell haemoglobin
concentration (MCHC) was calculated following the method of Dacie and
Lewis (1984) and lead levels were corrected for haemoglobin after
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