Plastics are useful materials with many clear benefits coming from its lightness and from being chemically inert; they can be flexible or rigid; transparent, translucent or opaque, and can be manufactured in any form or shape. They are widely used in areas like food and beverage packaging and in all kinds of everyday products and appliances.
On average plastic consumption reaches 100 Kg per person per year in Western Europe and North America.
The production of plastics in industrial scale began in the 1950’s, and since then they are increasingly pervading our society: on average plastic consumption reaches 100 Kg per person per year in Western Europe and North America and 20 Kg in Asia, and these figures are expected to grow rapidly in populated developing countries in Asia or Africa, as urban population increases.
But it is precisely its success and increasing use that is making it a threat to the environment, and specifically the marine environment — the final destination every year of more than 8 million tonnes of mismanaged plastic waste around the globe.
Once the plastic waste —bags, bottles, packaging, etc. – enters into the sea, it undergoes decades of photodegradation and other weathering processes which ends up with its decomposition into microplastics, tiny fragments of few millimeters in size, and even nanoplastics, in the nanometer scale. These may be uptaken by marine biota, from zooplankton to baleen whales.
As in any new field of research, there are currently more questions than certitudes with regard to the consequences of marine plastic pollution. Microplastics, now clearly present as a widespread and complex feature of marine pollution, can carry substantial concentrations of a range of chemical additives like endocrine disruptor chemicals (EDCs) and also adsorbing and concentrating polluting substances in the water. They therefore contribute to the exposure of marine species to hazardous chemicals, with unforeseen consequences.
Knowing the consequences and finding the solutions
In a scenario of “business as usual”, it’s expected that in 2050 there will be more plastic than fish in the oceans. Our recent paper presents the consequences of the increasing presence of plastic waste in all the seas, focusing on the chemical pollution derived from common chemical additives in plastics with endocrine disruptor properties, which may affect marine biodiversity and theoretically even human health.
In a scenario of “business as usual”, it’s expected that in 2050 there will be more plastic than fish in the oceans.
Solution to plastics in the oceans must include product and infrastructure design as well as consumer behavior. In our publication we propose measures like:
- Encouraging plastic waste prevention and supporting development and implementation of safer or more benign alternatives to persistent plastics in the marine environment.
- Promoting substitution and green chemistry to avoid harmful chemicals in plastics, especially Endocrine Disruptor Chemicals (EDCs).
- Encouraging ecodesign for better packaging recyclability.
- Encouraging plastic waste recycling when feasible.
- Encouraging changes in consumption and littering behavior.
- To assist developing countries, economies in transition and Small Island Developing States with efficient collection and environmentally sound management of plastic waste and plastic packaging, which they are unable to dispose of or recycle in an environmentally sound manner but continue to receive nonetheless, including through take-back or repatriation policies under extended producer responsibility (EPR) schemes.
Among the authors of the publication there are environmental chemists, marine scientists and environmentalists.
Dr. David Santillo, from the Greenpeace Science Lab in Exeter University (UK), who has recently conducted a study on microplastics in the Scottish Seas (photo) affirms that “It is already clear that the presence of microplastics in seawater can have physiological and behavioral consequences for marine organisms”, and that “even in remote waters around the Hebrides on the NW coast of Scotland, microplastics have become an unwelcome part of the fabric of marine ecosystems, and this threat to marine life cannot be ignored and requires urgent investigation”.
Joao Sousa, biotechnology engineer working at the IUCN (International Union for the Conservancy of Nature) in Switzerland, has recently returned from an expedition to Sweden and Finland, where they collected ice-cores. The findings affirm that Artic Sea ice has been shown to contain a concentration of microplastics which far exceeds the ones previously reported in highly contaminated oceanic waters, which are known as the plastic gyres.
The discovery presents a serious human health concern, as approximately 40% of the United States’ commercial fisheries (by weight) come from the Bering Sea and about 50% of the fish consumed in the European Union comes from the European Artic.
Professor Cristina Fossi, from the University of Siena (Italy), has studied the impacts of contaminants on Mediterranean marine organisms over a 20 year period and more recently, the Gulf of California.
In 2012 she published the first paper on the impact of microplastics in baleen whales, a species that can be hugely impacted by microplastics, because each time a whale opens its mouth, it filters 70,000 litters of water!
All these small pieces of plastics could be toxic for organisms, as the plastic itself is full of contaminants, particularly plastic additives, such as phthalates, biphenyl A, PBDEs. When they are eaten by a fish and arrive in its stomach, the contaminants are released and produce toxic effects. They can impact on the endocrine system of the fish and on its sexual hormones.
Professor Fossi and colleagues are trying to identify the effects of contaminants transported by the microplastics throughout the whole food chain, using biomolecular techniques. For example: measuring the increase or decrease of the level of a protein or DNA damage, by using several techniques from PCR real time to WB and gene expression.
She is currently leading a European Union project, the Plastic Busters, in order to assess the amount, sources, pathways, distribution convergence areas and effects of marine litter on biota as well as mitigate and reduce the impact of marine litter in the Mediterranean Sea.