Microplastics pollution: an emerging threat? Dr Peter J Kershaw Marine Environmental Protection Specialist peter@pjkershaw.com http://www.pjkershaw.com Chairman of GESAMP (Joint Group of Experts on Scientific Aspects of Marine Protection) Advising eight United Nations Agencies http://www.gesamp.org
Microplastics as an emerging issue international response 2010 2008 & 2010 2013
Microplastics as an emerging issue response by research community Number of publications 50 40 30 2008 & 2010 10 Publications, 1970-2013 Plastic pellets Microplastics 2010 0 1970 1980 1990 2000 2010 2013 Year (Data compiled by Sarah Gall, Univ. Plymouth)
Questions about microplastics: What are they? Where are they? Why are they there? When were they first detected? Why should we be concerned? What can we do about it? How are they observed and sampled? Critical review: Hidalgo-Ruz et al., 2012, Env. Sci.Technol., 3060
What are microplastics? Operational definition < 5mm Plastic resin pellets, used in plastics manufacture, accidental release Plastic particles used in industrial & domestic applications e.g. cleansers, toothpaste & shower gel (A Bakir and RC Thompson) primary (Ogata) secondary i.e. fragmented Household objects, fishing gear, balloons, fabrics etc Transport, fragmentation, float/sink (Hawaii, NOAA Marine Debris Program) Released into the environment, deliberate & accidental (Mar. Conservation Soc., UK)
Where are they? Beaches* Water column* - globally Seabed Inside organisms* Image: Algalita * 1st reported as small polystyrene spherules, polyethylene cylinders, small pieces of plastic. in 1972 Fulmar stomach contents, North Sea (Van Franeker) Microplastics in surface waters, western North Atlantic, 20 year compilation (Law et al., 2010)
Simulating the distribution of floating microplastics using ocean circulation models Simulation of drifter density (or marine debris) from a homogenous initial state After 1 year After 10 years Med (Nicolai Maximenko, IPRC 2008) 5 Gyres
Modelling distribution using Proxy indicators of littering as a Pressure 1. Shipping density 2. Coastal population density 3. Area of impervious urban catchment (does not include fisheries/aquaculture) Med Estimated distribution of plastic particles using an ocean circulation model, (Laurent Lebreton)
Simulated distribution of plastic fragments from proxy sources (Laurent Lebreton, unpublished) Distribution by counts Distribution by mass Micro-debris <4.75mm (Macro-debris >4.75mm
Uptake of contaminants by plastics - International Pellet Watch Air Mail Laboratory of Organic Geochemistry, Dr. Hideshige Takada, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan Global Monitoring of Persistent Organic Pollutants (POPs) Using Beached Plastic Resin Pellets: e.g. PCBs, DDT, PAHs, HCHs (hexachlorocyclohexane pesticide) 10
International Pellet Watch http://www.pelletwatch.org/maps/ Maps plus sampling details
Microplastics - a source of chemical exposure in organisms? PBTs & POPs potential effects seawater prey species predator human consumption plastic additives PBTs Persistent Bio-accumulating & Toxic compounds POPs - Persistent Organic Pollutants Stockholm Convention Examples: PCBs, DDT & other pesticides, flame retardants
Evidence of gut transfer of POPs from plastic vs. prey? PBDE flame retardants in short-tailed shearwaters, northern North Pacific Ocean PBDEs (polybrominated diphenyl ethers) - used as a flame retardant on textiles & as an additive in some plastic products Kosuke Tanaka, Tokyo Univ. Agric. & Technol. Tanaka et al., 2013, Mar. Poll. Bull., 69, 219-222 5mm squares Additional evidence: Rochman et al., 2014, PBDEs in fish South Atlantic Fossi et al., 2012, phthalates in fin whale, Mediterranean Endocrine disrupters
Increasing bromination PBDE flame retardants in short-tailed shearwaters finger-printing the type of PBDE * * * * * High plastic loading
finger-printing the type of PBDE PBDEs in adipose tissue of shearwater * * * * PBDEs in plastic in stomach PBDEs in natural prey * High plastic loading
Why micro-plastic pollution can be considered a growing threat: Increasing in abundance Ingested by large variety of organisms May cause physical harm Additives may have an ecotoxicological effect Absorbed organic contaminants may have an ecotoxicological effect Emerging evidence of transfer of chemicals from plastic particles to tissue Cannot remove them from the environment in significant quantities
What can we do about it? Primary microplastics Prevent entry into the marine environment by improved waste management Reduce use of plastics in abrasives, e.g. substituting plant or mineral material Secondary microplastics Improve overall waste management on land and at sea - & public attitudes Reduce accidental loss of fishing gear & other materials at sea Remove plastic items from coastlines, rivers & other points of entry Algalita
Thank you! peter@pjkershaw.com http://www.gesamp.org GESAMP Working Group 40 Sources, fate & effects of microplastics in the marine environment a global assessment Reporting: November 2014 Supported by: UNESCO-IOC, UNEP, IMO, UNIDO, UNDP, NOAA, ACC, Plastics Europe