On the show, the feathers tested were from birds that had a lot of
pieces of plastic in their stomachs. It would be relevant to know if the
muttonbirds and muttonbird oil sent to the Australian Food Standards Lab
were from particular birds that had plastic in their stomachs, or were
from a random selection of birds that might or might not have eaten
plastic. That would make a big difference to the results.
Cheers,
Merrilyn
On 7/09/2012 10:48 AM, Jeremy O'Wheel wrote:
It's a good question, especially her claims about seafood (which is very
regularly checked for contaminates, especially heavy metals). But what she
says could be true - I'm not claiming that it's false, just that it's
contested. I'm probably biased in how well I know Maureen too. There are
certainly other studies that have found no meaningful amount of
contamination in the flesh of seabirds that are consumed (such as Bekhit et
al. (2012) Concentrations of trace elementals and organochlorines in Mutton
bird (Puffinus griseus) published in Ecotoxicology and Environmental Safety
76(1), pg 226 - although it did find small amounts of heavy metals and that
some were increasing, although they checked 22 and found 3 were increasing
with p>0.5, so that could just be coincidence ( http://xkcd.com/882/ ).)
It sounds to me, as an interested layperson observer, that the differences
of opinion mainly come from the methods used. Lavers measures toxicity
from feathers and gets very high results. Others measure from the actual
flesh, and get almost nothing. So extrapolating meaning from the results
might be rash, but the science as the basis of the media reports is not
necessarily wrong (it's possible that the differing results are not
mutually exclusive). I note that nobody that I can find has published
mechanistical papers on this topic though - ie. the connection between
heavy metals in birds and plastics pollution hasn't been studied.
Anyway I'd be interested to hear a reply. I can also give you Lavers email
address if you'd like to ask her anything directly (or you could try her
website): http://www.jenniferlavers.org/
Cheers,
Jeremy
On Fri, Sep 7, 2012 at 9:16 AM, Carl Clifford <>wrote:
Jeremy,
Very interesting. Why would a fairly high profile TV show and researcher
make such statements, when the statements would appear to be without
supporting evidence? I will contact the Catalyst crew and ask if they can
supply supporting evidence for the claim of heavy metal adsorption to
microplastics. I will post their responses on B-A, if there are any.
Cheers,
Carl Clifford
On 06/09/2012, at 11:31 PM, Jeremy O'Wheel <> wrote:
My email and response on this topic!
---------- Forwarded message ----------
From: Maureendavey
Date: Thu, Sep 6, 2012 at 10:49 PM
Subject: Re: ABC Catalyst - seabird heavy metals
To: Jeremy O'Wheel <>
Hi Jem
I have been sick all week with a sore throat and constant cough. So
miserable. But only a week ago I was relaxed, happy, holidayed so I'm
looking forward to a return of that state, hopefully tomorrow!
Jennifer Lavers is the woman who asserted that (Tasmanian) muttonbirds
had
high levels of heavy metals, but when we (TAC and DHHS) sent muttonbirds
and muttonbird oil to the Australian food standards laboratory for
analysis
the levels of heavy metals were either undetectable or well within safe
limits. We were transparent about the source of muttonbirds sent for
analysis (3 different commercial rookeries from 2011 season), could trace
their journey from rookery to laboratory, used a reputable laboratory
accredited to analyse foods for metal contamination, and shared results
with Lavers and colleagues.
Her lab was not prepared to be open about their methodology or their
detailed results, but that hasn't stopped them making claims in the
media.
Their previous work has been on analysing feathers, and like hair
analysis
in humans, it is not a reliable indicator of what is going on inside the
body. Heavy metals can be found in hair or feathers for many reasons, but
frequently the source is external contamination.
I agree decreasing the extent of plastic pollution would be a good thing,
but I think claiming this leads to heavy metal toxicity in the chicks of
migratory birds such as shearwaters lacks scientific plausibility and I
am
yet see any reputable and reproducible evidence of contamination of the
flesh.
Thanks for sending me the link.
Maureen
On 06/09/2012, at 9:12 PM, "Jeremy O'Wheel" <> wrote:
Hi Maureen,
How are you? It sounded like you had a good trip to NSW with Mon!
I was wondering if you saw this;
http://www.abc.net.au/catalyst/stories/3583576.htm
People on one of my birding email lists have been talking about it. Do
you
have an opinion on it that I could convey to them?
Cheers,
Jeremy
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