the environment. These substances can leach out of plastic into the environment, affecting the health of wildflife.2 Some additives are also of concern to human health. An example is the potential leaching of bisphenol A from plastic containers into the food it contains. Another is the possible migration of flame retardants from plastic computer enclosures into dust that humans breathe. Workers can also be exposed to additive leachate during the manufacturing stage. For example, trimethlytin chloride due to the use of methlytin stabilising agents in PVC products is linked to the increased risk of developing kidney stones in workers in the United States and China.15 Plastic presents further risks and costs once it is thrown away at the end of its life. Globally, between 22% and 43% of plastic waste is disposed of in landfills, where the resources it contains are wasted. Landfill sites can blight local communities due to their undesirable nature and by using up valuable space. If plastic is mixed with other materials, sorting the waste to collect useful materials becomes more complex, costly and dangerous. Some plastic waste goes to incineration – up to 21% in developed countries where most incineration plants are designed to generate energy. However, generating such energy from these waste plants is in some cases inefficient, requires pollution abatement to control air emissions, and the incinerator ash is classified as a hazardous waste. Waste management, while necessary and better than littering, is costly and wastes resources that could be put to good use through recycling. Inadequate waste management is expensive to society and often not internalised by businesses. Collection costs range from $20 to $250 per tonne depending on the region, while landfill costs $10- $100/tonne and incineration with energy recovery $40-200/tonne.8 According to the World Bank, the quantity of waste and related cost is likely to double by 2025.8 With many countries un-prepared to handle this increase, waste and resource management will be an increasingly important issue in the years to come for companies, particularly those who operate across borders. Plastic is one of the toughest waste streams to handle, and though the weight of plastic waste might not be as big as that of other materials, its durability and volume often account for a large proportion of a country’s waste issues. The highest profile impact of waste plastic is when it is littered. Once littered, it is costly to recover and becomes a multigenerational problem due to its long degradation time. Although it is typically only considered an eyesore, its impact is felt throughout our communities, environment and increasingly the ocean. Litter has an impact on land use, transport, animal and human health, safety, flooding, community spirit and clean-up costs. It often makes its way to the ocean over time, due to its light weight and durability, blown by the wind or via rivers and drains. While there is much uncertainty about the extent of the problem, a report by the United Nations Environment Programme (UNEP) estimates that 6.4m tonnes of litter enter the ocean every year – some eight million items every day.5 This figure is likely to be an underestimate as the underlying research was published in 1975. Other studies suggest between 10m and 20m tonnes a year.16,17 Plastic is the most common type of marine litter, comprising up to 80% of total waste in marine litter surveys. Most (over 80%) comes from land-based sources, with marine-based activities such as shipping, cruise lines and fishing accounting for the remainder.5 Studies show that levels of litter in the ocean are increasing in spite of efforts to control the problem. Industry bodies, businesses, governments, civil society and international institutions are recognizing the magnitude of the issue and the need to tackle it. As an example, many joined UNEP’s Global Partnership on Marine Litter (GPML) and the global plastic associations have signed a declaration to develop solutions to marine litter.18 Over two thirds of plastic litter ends up on the seabed with half of the remainder washed up on beaches and the other half floating on or under the surface, according to a report from UNEP.5 Over time, ocean currents drive plastic waste on the surface of the sea together into vast ‘ocean gyres’ such as the ‘North Pacific Gyre’, which has been nicknamed the ‘Plastic Vortex’ or the ‘Great Pacific Garbage Patch’. In reality, these gyres are more like a soup than a patch.19 Even the great depths of the ocean are polluted with plastic. Researchers using a remotely operated underwater vehicle to explore an area of seabed covering less than 1% of Monterey Bay in surface recorded over 380 pieces of plastic debris, with similar findings in the Mediterranean and North Sea.20,21,22 Plastic litter in the ocean kills, injures and harms wildlife. Larger items such as plastic bags, plastic strapping for packages and abandoned fishing gear can strangle marine animals. Bottle caps, plastic cutlery, pens and cigarette lighters can be ingested and harm animals through internal damage and starvation. There has been a 40% increase in the number of species reported to be affected by ingestion and entanglement between 1997 and 2012, across all marine debris types. Of 319 publications reviewed in the same 2012 report, the majority of reports (76%) described encounters with plastic debris as opposed to other types of material.6 Ingestion of microplastics may also have
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