Plastic Toxicity Working by Stealth in Oceans
By Shar Adams,
Epoch Times | May 28, 2014
SYDNEY – When dead seabirds washed up in their thousands along the
eastern and southern seaboards of Australia last year, biologist Dr
Jennifer Lavers became worried, very worried.
A research fellow at the Institute for Marine & Antarctic Studies
in Hobart, Dr Lavers had been studying flesh-footed shearwaters, also
known as mutton birds, for nearly a decade.
She knew that mass deaths, known as “wrecks”, were not uncommon for
the migratory shearwaters which travel huge distances from the Bering
Sea to Australia every year.
Wrecks of seabirds traditionally occur every ten years or so as a
result of large storms or lack of food. They begin in September as the
birds arrive exhausted from their travels and usually last a couple of
weeks.
But the wreck last year continued for an unprecedented four months,
and dead birds appeared in the tens of thousands on beaches from Mackay
in Queensland to Albany in Western Australia.
“It was quite unusual, to have birds washing up dead in January,
which is when their chicks should be hatching,” Dr Lavers said in a
phone interview.
Wrecks are becoming more common with seven events since 2007. Dr Lavers believes they signal a much wider problem.
She has been studying the effects of plastic on shearwaters and says that while there are many contributing factors to wrecks,
recent research indicates plastic is having a far more toxic effect on seabirds than first understood.
For one, the amount of plastic seabirds are ingesting has increased.
Around 79 per cent of seabirds studied contained plastic in 2007 but
that has now jumped to 100 per cent. Seabirds now contain “copious”
amounts of plastic, she said. On average, around 17 pieces of plastic
are found in a flesh-footed shearwater, but Dr Lavers says many contain
much more.
“It is not unusual in fleshfoots to find more than 100, or more than
200, pieces of plastic in a single bird. They are very heavily
impacted,” she said.
Toxicity of plastic
The amount of plastic in the ocean is well documented – the North
Pacific Geyre near Hawaii is just one of six eddies known to trap
oceanic garbage in patches of plastic and junk that extend over millions
of square kilometres.
But an understanding of the way plastic is impacting our world has
taken an alarming turn. In a new area of study, Dr Lavers joined forces
with neurologist Professor Richard Banati from the Australian Nuclear
Science and Technology Organisation (ANSTO).
Professor Banati had refined a technique called the tracer principle,
which involves using slightly radioactive tracers to study and track
materials at the molecular level. At ANSTO he has been working on
detection of contaminants in a wide range of ecosystems.
It appears that plastic, no matter how small or in what quantities,
increases in toxicity the longer it floats in the ocean, the process
releasing more and, at the same time, attracting more toxins.
“As the plastic floats in the ocean for weeks, months, decades, it
acts like a sponge or magnet. It takes all of the contaminants in the
ocean water that are diluted into low concentration, absorbs it, sucks
it up and concentrates it on the surface,” said Dr Lavers.
“The concentration of the heavy metals on the plastic can be more
than one thousand times the concentration of that same contaminant in
the ocean water.”
Those contaminants include heavy metals like lead, mercury and
cadmium, known to affect the liver, kidneys, respiratory and
neurological systems in animals and humans.
The two researchers discovered heavy metals in the feathers and wings
of sea birds, suggesting that those contaminants were being absorbed
into animal tissue. They found that plastic was acting as a facilitator
or conduit of contaminants into the animals system.
“Regardless
of the size…any plastic can act as a vector,” she said. “Hands down,
across the board, we now know this without a doubt.”
Dr Lavers also found a correlation between the birds’ condition and
the amount of plastic in the bird – the higher the amount of plastic,
the higher the level of heavy metals and the poorer the body condition,
including emaciation and dangerously short wing spans. The results are
ringing alarm bells.
“Seabirds are highly respected as indicators of the health of the marine environment,” she said.
Dr Lavers believes her discovery is ground breaking because
environmental scientists have traditionally focused on quantifying the
physical effects of plastics on sea life, like throat or intestinal
blockages and plastic bags wrapped around the head. A molecular pathway
of toxicity is a whole other level.
“What is happening we can’t see and that is far more widespread than anyone understands,” she said.
Rethinking plastic
While many people may be aware of the toxic nature of some plastics,
particularly Bisphenol A (BPA), vinyl chloride (PVC) and polystyrene,
the study highlights the dangers of any plastic including
biodegradables.
A combination of starches and plastic in the form of polychromes,
biodegradables can be broken down in industrial facilities using
specials conditions like extreme heat and other processes, but they do
not break down by floating around in cold ocean water.
“Plastic does not biodegrade, polymer chains do not biodegrade, that
is the definition of their chemical structure, they do not break down,
they truly last forever,” said Dr Lavers.
As a result of his molecular line of research, Dr Banati says the pervasive nature of plastic requires a rethink.
“A traditional approach to environment management has been ‘the
solution to pollution is dilution’. However researchers are becoming
concerned about this approach,” he said in a statement.
“Specifically we are finding that mass plastic consumption, together
with increased degradability of plastics, may actually lead to a steady
increase of hazardous contaminants in the environment which would be
difficult to reverse.”
Dr Banati says showing the traceablity of plastics allows a more
comprehensive analysis of the lifecycle of plastic well beyond what can
be seen with the naked eye.
The results indicate clear environmental, biological and social
concerns and raise questions about industry standards for reusable or
biodegradable plastics and for their collection.
“These are interesting questions and, if anything, what research at
the atomic scale shows is that they are at least worth putting out there
and discussing,” Dr Banati said.
