Lead Toxicity in Mute Swans

I
centrifugation in microhaematocrit tubes for · 30 mins at 12,000 x G
(determined stroboscopically) in a Hawksley microcentrifuge.
Other blood chemical parameters were estimated as follows:
Aliquots of blood specimens collected in lithium heparin tubes were
spun in a microcentrifuge (10,000 X G) for 5 mins.
The plasma was
removed and placed in cuvettes for analysis. Analysis was carried out
in a selective multichannel autoanalyser (Hitachi Model, 737).
A
scanning wavelength of 340 to 700 nm was set, using a Halogen lamp
source and a 0.6 cm light path.
Calibration was based on Serva
validated reference serum and normal saline (0.9% W/V), was used as a
blank.
Protoporphyrin ( free red blood cell protoporphyrin) was determined
following a double phase extraction technique (after Peter~ al.,
1978). Protoporphyrin IX standards were obtained from Porphyrin
Products (Logan, Utah, U.S.).
Fluorescence was measured on a Farrand
Mark 1 Spectrofluoremeter with a primary filter of 405nm and a
secondary filter of 600nm using a Xenon lamp and lOnm slit widths.
Lead and protoporphyrin values were related to haemoglobin content
(after O'Halloran et al., in press).
Lead levels in blood and tissues were estimated following acid
digestion, using an SP192 Flameless Atomic ~bsorption
Spectrophotometer
(for details see O'Halloran and Duggan, 1984).
Liver and kidney lead
levels in excess of 12.50 ug/g and 31.25 ug/g wet matter were
considered diagnostic of lead poisoning after Clarke and Clarke (1975).
Statistics.
Blood chemistry and haematological reference distributions were
calculated using a reference value statistical package based on the
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