Plastics production has gone up 560-fold
in just over 60 years to 280 million tonnes a year, less than half recycled or
buried in landfills, the rest litter the oceans damaging marine life throughout
the food chain; scientists call for the most toxic plastics to be classified hazardous
waste, and ultimately for all plastics to be reused and recycled in closed-loop
systems Dr Mae-Wan Ho
Over five trillion pieces of waste plastic
are floating in our oceans weighing 268 940 tonnes and causing damage
throughout the marine food chain, according to data collected by a team of scientists
from the United States, France, Chile, Australia and New Zealand [1, 2]. The team
went on 24 expeditions between 2007 and 2013 that surveyed all five
sub-tropical gyres (large rotating ocean currents): North Pacific, North
Atlantic, South Pacific, South Atlantic and Indian Ocean, and extensive coastal
regions and enclosed seas (Bay of Bengal, Australian coasts and the
Mediterranean Sea), and include surface net tows and visual transects for large
plastic debris at 1 571 locations in all oceans.
This is the most
comprehensive survey to-date, yet it is most likely a gross under-estimate of
the scale of waste plastic pollution in the oceans.
Waste plastic an escalating
In 2012, 280
tonnes of plastic was produced globally; less than half consigned to landfill
or recycled. Much of the remaining 150 million tonnes not still in use litters
continents and oceans . Global trends suggest that waste plastics are
accumulating exponentially in parallel with trends in plastic production that
has increased 56o fold in just over 60 years. These by-products of the
oil industry are icons of the industrial economy built on the over-exploitation
of oil and other fossil fuels that's turning the planet literally into a
terminal wasteland  (Redemption from the Plastics Wasteland,
The estimate from the global survey of plastic pollution on the sea
surface for all fragment size classes combined is only 0.1 % of the world
annual production. The estimates are “highly conservative”, the team
acknowledged . They do not account for the potentially massive amounts of
plastic washed up on shorelines, submerged on the seabed, suspended in the
water column, and inside organisms. Also, the survey only collected particles
larger than 0.33 mm, due to the size of the netting used. Sequestration in the sediment
is the likely fate of plastic pollutants after perpetrating numerous impacts on
organisms along the way.
Waste plastic in
the open ocean is degraded into smaller and smaller fragments through UV
radiation, mechanical abrasion, biological degradation, and disintegration. The fragments disperse in the ocean, converging in the subtropical
gyres. Generation and accumulation of plastic pollution also occur in closed
bays, gulfs and seas surrounded by densely populated coastlines and watersheds.
The impacts through ingestion and entanglement of marine organisms ranging from
zooplankton to whales, seabirds and reptiles are well documented, and new studies
are showing up harmful effects of nano-size plastic particles that have escaped
inventories so far (see  Plastic Poisons in the
Food Chain, SiS 65).
The data from the global
survey showed that during fragmentation plastics are lost from the sea surface
. There is a 100-fold discrepancy between the expected microplastics (particles
< 4.75 mm) weight and abundance and the actual amounts observed, indicating
a tremendous loss of microplastics. This suggests removal processes are operating,
including UV degradation, biodegradation (by microorganisms), ingestion/absorption
by organisms, decreased buoyancy due to fouling organisms, entrapment in settled
detritus, and beaching. Fragmentation rates of already brittle microplastics
may be very high, breaking them down into ever smaller submicron or nanoparticles,
and unrecoverable by the nets. Numerous studies demonstrate that many more
organisms ingest small plastic particles than previously thought, either
directly or indirectly via their prey organisms. These are then packaged into
faecal pellets which sink to the bottom. Further, there is evidence that some
microbes can degrade microplastics.
Plastics should be classified hazardous
A team of scientists led by Chelsea Rochman
at University of California Davis and Mark Anthony Browne at University of
California Santa Barbara in the United States wrote a Commentary in the journal
Nature in 2013 calling for the need to classify plastics hazardous waste
They point out
that plastic debris can physically harm wildlife. Many plastics may be
chemically harmful either because they are themselves potentially toxic or
because they absorb other pollutants. Waste plastics can kill or damage
ecologically and commercially important species including mussels, sea-marsh
grasses and corals. Mammals, reptiles and birds can be harmed through ingesting
plastic or becoming entangled in it. In 2012, the secretariat of the Convention
on Biological Diversity in Montreal Canada reported that all sea turtle species,
45 % of marine mammal species and 21 % of seabird species can be harmed in that
way. Yet in the US, Europe, Australia and Japan, plastics are classified as
solid waste and treated like food scraps or grass clippings. Policies for
managing plastic debris are outdated and severely threaten the health of
As plastic breaks into
smaller pieces, it is more likely to infiltrate food webs. In lab and field
studies, fish, invertebrates and microorganisms ingest micrometre sized or
smaller particles, which also come from synthetic (polyester or acrylic)
clothing and cleaning products containing plastics. Studies in humans and
mussels have found that ingested and inhaled microplastics get into cells and
tissues where they can cause harm. In patients who have had their knee or hip
joints replaced with plastic implants, such particles can disrupt cellular
processes and degrade tissues.
Toxicities of plastics
Plastics are made up of repeating units or
monomers that join up to form long chains or polymers. These chains are thought
to be generally inert; yet unreacted monomers and other harmful ingredients can
be found in plastics. According to United Nations’ Globally Harmonized System
of Classification and Labelling of Chemicals, the chemical ingredients of more
than 50 % of plastics are hazardous. Studies investigating the transfer of
additives in polyvinylchloride (PVC) from medical supplies to humans indicate
that these chemicals can accumulate in the blood. In lab tests, monomers and
other ingredients of PVC polystyrene, polyurethane and polycarbonate can be
carcinogenic and can affect organisms in similar way to the hormone oestrogen.
The monomers making up some plastics such as polyethylene (used for carrier
bags) was thought to be more benign. Yet these materials can still become toxic
by picking up other pollutants. Pesticides and organic pollutants such as
polychlorinated biphenyls are consistently found on plastic wastes at harmful
concentrations 100 times those found in sediments and 1 million times those
occurring in sea water. Many of these are ‘priority pollutants’: chemicals
regulated by government agencies, including US Environment Protection Agency
(EPA) because of their toxicity or persistence in organisms and food webs.
These chemicals can disrupt processes such as cell division and immunity,
causing disease or reducing the organisms’ ability to escape from predators or
In an unpublished
analysis, the authors found that at least 78 % of priority pollutants listed by
the EPA and 61% listed by the EU are associated with plastic debris. Seabirds
that have ingested plastic waste have polychlorinated biphenyls in their
tissues at 300 % greater than those that have not eaten the plastic.
Classify the most
harmful plastics as hazardous
Governments have struggled for decades to
reduce plastic debris. The International Convention for the Prevention of
Pollution from Ships (MARPOL) was signed in 1973, although a complete ban on
the disposal of plastics at sea was not enacted until the end of 1988. Despite
134 nations agreeing to eliminate plastics disposal at sea, ocean sampling
suggests that the problem has persisted or worsened since MARPOL was signed.
scientists wrote : “We feel that the physical dangers of plastic debris are
well enough established, and the suggestions of the chemical dangers sufficiently
worrying, that the biggest producers of plastic waste - the United States,
Europe and China - must act now. These countries should agree to classify as
hazardous the most harmful plastics, including those that cannot be reused or
recycled because they lack durability or contain mixtures of materials that
cannot be separated.”
Focusing on the most hazardous plastics is a realistic first
step. Currently, just four plastics - PVC, polystyrene, polyurethane and
make up roughly 30 % of production. These are made of potentially toxic
materials and difficult to recycle. PVC is used in construction, such as pipes
that carry drinking water; polystyrene is used for food packaging; polyurethane
in furniture; and polycarbonate in electronics. Health-care and technology
industries are already replacing PVC components in intravenous-drip bags and in
computers with materials that are safer, more durable and recyclable, such as polypropylene
the proposed change in plastics classification, many affected habitats could
immediately be cleaned up under national legislation with government funds.
In the United States, for instance, the Comprehensive Environmental Response,
Compensation, and Liability Act of 1980 would enable the EPA to clear the vast
accumulations of plastics that litter the terrestrial, freshwater and marine
habitats under US jurisdiction.
the scientists want changes in regulation to drive the development of a
closed-loop system in which all plastics are reused and recycled, instead of ending
up in landfills where chemicals leach from the plastic into surrounding
current consumption rates continue, the planet will hold another 33 billion
tonnes of plastic by 2050. This would fill 2.75 billion refuse-collection
trucks, which would wrap around the planet roughly 800 times if placed end to
end.” The scientists wrote . “We estimate that this could be reduced to just
4 billion tonnes if the most problematic plastics are classified as hazardous
immediately and replaced with safer, reusable materials in the next decade.”
Dr. See Ing Or Comment left 28th January 2015 14:02:16 After reading the article on the danger of plastic plague in our Ocean. I am wondering whether the PVC pipes that channel water in the homes can pose health hazard by drinking that water?
Isn't it pose greater direct hazard to human than those present in the seas?
Mae-wan Comment left 28th January 2015 15:03:22 Dr. See Ing Or, vinyl chloride can indeed leach from PVC pipes and pose hazards to health The EPA information page on this is here: http://water.epa.gov/drink/contaminants/basicinformation/vinyl-chloride.cfm
Rory Short Comment left 28th January 2015 16:04:54 It seems to me to be completely logical that no products containing non-natural chemicals should be allowed into the market until the chemicals have been independently tested and proven to be a non-harmful addition to the environment.
Linda Tanner Comment left 28th January 2015 16:04:59 @Dr. See Ing Or: the glues used to adhere PVC piping at junctions, couplings, etc., might represent an even greater threat, more easily leaching into any water flowing through, and especially into water standing in pipe (while waiting to flow).
Linda Tanner Comment left 28th January 2015 16:04:09 Excellent article.
And for a visual of what we are doing to our wonderful planet:
Patricia P Tursi, Ph.D. Comment left 28th January 2015 16:04:34 In the nineties, we bare-boated in the Lesser Antilles and I was delighted to be on a sailing sloop which was environmentally safe. But I learned that when entering a harbor, the motors go on and the sails go down as energy is needed to run refrigerators, etc. An eyeopener. Visitors from all over the world kill harbors like this daily.
Dr R K S Rathore Comment left 29th January 2015 08:08:47 After going through this article, it appears that our so-called civilized activities of promoting tourism, sports and many others result in, one way or the other, to add non-degradable waste material in to our food chains. Use of PVC pipes is increasing day by day, for getting potable drinking water from underground or municipal water supply. Let us develop a global thinking for this global problem. This article is an eye opener.