Plastic Soup on our Plate
Jan Andries van Franeker, Milieu 2011/6
The soup of small plastic particles in the oceans represents a major global environmental problem. Plastics not only result in entanglements and constipated guts among birds and fishes, but toxic contents may also endanger the marine food chain. Measures to prevent the soup from becoming thicker and more poisonous, such as high deposits for return fees on single-use plastic products, and also a ban on packaging materials made of plastics that are supposed to be degradable, are urgently needed.
«Oceanic plastic islands» may not yet truly exist, but the reality of the global soup of small plastic particles is an even more serious problem (Hans van Weenen, Milieu, 2011–12). Although we do not know how hot the soup on our plate will be, there can be no doubt that we will be on our table. Only a small proportion of the annual production of 250 million tons of plastic needs to enter the marine environment to create an immense problem. Plastics are, for the most part, not degradable, and at best fragment into ever-smaller microparticles. Combined with the increasing amount of plastics produced in microscopic sizes, the tiny particles will contribute to a constant thickening of the plastic soup in the oceans. The soup differs in density depending on the situation. Part of the materials will sink and accumulate on the bottom or in the sediment. Floating or suspended debris not only accumulates in the center of large oceanic gyres (the so-called garbage islands) but can be found anywhere winds and currents force materials together. Such situations exist in the North Sea, the Mediterranean, and elsewhere in our oceans. Even if we do not always know where the soup is thickening, we can be absolutely certain that it will continue as long as we do not stop the further leakage of plastic into the environment.
Larger animals such as marine birds and mammals are well known for the ingestion of plastic debris. Almost every species will occasionally have plastic in their stomach. Many tube-nosed seabirds (albatrosses and petrels) and marine turtles have plastics in their guts all the time. Ingestion is even so common that we now use the stomach contents of northern fulmars as the standard monitoring tool to measure the environmental quality in the North Sea for marine debris. Each year, stomachs of fulmars are analyzed for their plastic contents. In the period 2005–09, a total of 916 fulmar stomachs were opened, of which 95 percent contained plastic. On average each North Sea fulmar carried approximately thirty plastic particles in the stomach weighing roughly 0.33 gram per bird. Birds from the most polluted parts carry about twice the average amount. Perhaps a few tenths of a gram do not sound so terrible, but if you translate that to a fulmar of human proportions, such a quantity equates to a lunchbox full of plastics in the stomach.
Seabirds as Transformers
From research in the Antarctic we have learned that birds returning from wintering areas with stomachs full of plastic lose approximately 75 percent of such plastic per month in the clean Antarctic environment. They grind plastics in their muscular stomach down to a size that allows intestinal passage and excretion. Just for the North Sea, it can then be estimated that fulmars reshape and relocate about six tons of ingested plastic every year. Globally, hundreds of tons of plastic must be processed and redistributed by marine animals.
A Little Bit Dead
Plastic not only has a broad range of dangerous substances built into the material during the production process (fillers, softeners, colorants, antioxidants, biocides, flame retardants, etc.), but in seawater plastic particles also act as sponges for dissolved toxic substances such as PCBs and pesticides. During the long period of residence and grinding of plastic in the fulmar stomach, such chemicals may become available for absorption by the organism. So besides the physical impact from plastic in the stomach (tissue damage, constipation, decreased sensation of hunger) there are major additional chemical risks from exposure to and accumulation of toxic substances that are carcinogenic or disturb nervous or hormonal systems. It would be a serious mistake to measure the risk of plastic pollution just from the animals killed more or less directly. Images of a whale entangled in ropes, or a marine turtle completely filled with plastic waste, are certainly dramatic and attract a lot of media attention. However, if a large number of individuals suffer from a lightly deteriorated body condition, the consequences in lowered survival rate and reduced reproductive success may represent a major risk for the population as a whole. Each and every individual is then «a little bit dead».
The important issue is how we should deal with the certainty of increases in (micro-)plastics in the marine environment and the uncertainty of its impacts. In my opinion, the irreversible nature of plastics once lost, its chemical characteristics, and the certainty of its interaction with living organisms are sufficient reason to apply a common-sense approach. This means that our highest priority should be to ensure that there is no additional plastic waste released into the marine environment. Better safe than sorry! A broad range of dedicated sectorial policy measures in, for example, shipping, harbor policies, fisheries, aquaculture, and awareness raising among the general public will be useful, but insufficient. Bioplastics, contrary to what many people think, will not contribute to a solution. The name suggests that plastics made from such substances as corn or grass are environmentally friendly and degradable. But that is a mistake, as plastics made from natural, renewable materials are often as poorly degradable like traditional plastic made from mineral oil. In itself, bio-based plastics are a useful development, but mainly to reduce our dependence of fossil fuels. If we really want to make a difference, we must fight the uncontrolled growth of single-use plastic packaging. Obligatory, high deposit fees should force the industry in the direction of returning used packages, re-use, and the use of uniform and pure materials that allow and stimulate true recycling loops. Government action will be needed for this. The «Plastic Heroes»* system may create a nice image sticker for the industry but uses end-of-pipeline mixed-waste streams, which certainly cannot be termed as proper recycling. Packaging that, according to producers, cannot be adapted to a deposit/return system or that produces an impossible mix of materials (e.g., the plastic screw cap on tetrapacks) should be heavily taxed to cover costs to society and maintain pressure in development of better alternatives.
No! to Degradable Plastic
For single-use packaging, the so-called degradable or compostable plastics may seem attractive, but they represent a totally counterproductive alternative. A plastic that is truly degradable in the natural environment or home-composting system will usually lack the characteristics that we expect from a plastic. In terms of recycling, these materials are unfavorable because, mixed with traditional plastic, they have a strongly negative impact on the quality of recycled materials. The currently approved governmental standard for «compostable» plastics is in fact not much more than making the production of microplastics legal. Even under optimal industrial composting the standard allows a remainder of microplastic. This is not what consumers expect, and this regulation needs to be changed urgently. Plastics are fantastic, with many extremely useful properties, among which however degradability simply does not fit! We should attribute a high value to plastics in order to ensure careful and sustainable use. If we don’t, we should not be surprised to find it back on our own plate!
(*) Plastic Heroes: www.plasticheroes.nl
Jan Andries van Franeker, «Plastic soep komt op ons bord», Milieu 2011 (6), S. 8-11
Jan Andries van Franeker, Marine biologist, works on the Dutch island Texel at the Ecosystems department of IMARES (Institute for Marine Resources and Ecosystem Studies; part of Wageningen University and Research WUR).