Chickens lickin’ lead poisoning
By Paul Maguire, Environment Reporter, Newcastle Herald, Friday April 29, 1994.
LEAD BATTERY HENS cartoon by Lewis.
EditorO’s Note: square-bracketed text added by Elizabeth O’Brien, The LEAD Group, April 18, 2016.
They apparently cope with blood-lead levels that would kill humans and other animals, yet hardly any of this poison passes through to their eggs or flesh.CHOOKS may not be the smartest things on two legs, but unique research at Lake Macquarie [the Council area near Newcastle in New South Wales which is home to the (now-closed) Pasminco Lead Smelter at Boolaroo] indicates that they can certainly deal efficiently with lead contamination.
This is the outcome of a Hunter Area Health Service [local area health service of the Hunter Valley of which Lake Macquarie Council is one local Council] public health study of lead impacts on chooks at Boolaroo and Argenton [a neighbouring suburb of Boolaroo].
The unit’s director, Dr John Stephenson, was astounded by the extremely high blood-lead levels in the domestic fowls, and the fact that they seemed to function normally and then passed so little of the toxic chemical to their eggs or flesh.
In laymen’s terms, the results strongly implied that there was no danger to humans who ate chicken meat or eggs from northern Lake Macquarie backyard chooks.
The study resulted from resident concerns that eggs and chicken meat produced near Boolaroo’s Pasminco zinc-lead smelter could be unfit for human consumption.
Lead contamination [poisoning] reduces children’s intelligence quotas, has been linked with [increased] blood pressure in humans, accumulates in pregnant women and can be passed to unborn children.
One of the tested chooks was found to have 435mg [correction, micrograms (µg), not milligrams (mg)] of lead for every decilitre of its blood [435µg/dL].
The health unit’s senior environmental health officer, Mr John James, who conducted the chicken experiment, said dogs were known to die at 80µg [80µg/dL] and humans showed lead poisoning symptoms at 60 µg [60µg/dL].
The chicken’s level was more than 10 times the highest blood-lead rating found during extensive investigation of the lake region’s youth.
The National Health and Medical Research Council set 10µg [10µg/dL – in May 2015 this level was re-set to 5 µg/dL] lead in human blood as a standard point where neurological damage was known to occur.
Twelve backyard Boolaroo chooks and six from Argenton were compared with seven in pens at Medowie [a suburb 45 minutes drive or 44 kms away from Boolaroo, north of the city of Newcastle] for the study.
Dr Stephenson said the small amounts of lead that were detected in eggs and chickens from Boolaroo and Argenton were well below Australian Food Code safety standards.
The findings should help to reassure the community, he said
Dr Stephenson said chooks must have a different way than humans of breaking down lead [compounds?] in their systems.
Some lead went into the chooks’ bones and he believed a lot must be excreted in their faeces.
He was unable to comment on whether chooks were too smart or too dumb to be affected by lead.
The chooks appeared to live normal lives and no tests were done on their intelligence.
Dr Stephenson said the chooks probably took in so much lead because they spent much of their time scratching and pecking obviously lead contaminated dirt.
Mr James said the tests, which are understood to be a world-first and have not yet been published in any medical journal, indicated the need for more research.
He said the chooks could have taken in lead from food, water, dust and the air.
A Boolaroo resident and spokesman for the community group No-Lead Mrs Theresa Gordon said she would have to personally assess the study’s findings before she considered eating eggs or chicken meat grown in her area.