Sometimes it feels like we are simply drowning in plastic. Over the past five decades plastic products have found their way into almost every aspect of our daily lives. Global plastic production has reached a total of 8bn tonne – that’s 1 tonne for every person currently on the planet – with plastic pollution expected to triple by 2060.
Current best estimates are that only about 10% of plastic ever produced has been recycled. Despite this, the idea of circular economy in the plastics industry is often cited as the magic bullet: we will simply reuse the plastic we have already made and reduce the impact of plastic pollution. But new evidence points to the flaws in this plan. A report by Greenpeace has found that recycled plastic can be even more toxic, and is no fix for pollution.
It is now well known that plastic pollution is ubiquitous across the planet, with evidence of plastic particles being found in the deepest parts of the ocean, from the Mariana Trench to the peak of Mount Everest. There is justified concern about the impact of this pollution, both on ecosystems and human health. However, as an environmental chemist who has been studying plastic in the environment, I am increasingly concerned by a more hidden “invisible” threat posed by plastics: toxic chemicals.
It is estimated that more than 13,000 different chemicals are involved in the production of plastics, and many of these have never been assessed for their toxicity. Chemicals are used alongside the plastic polymer itself to create the desired physical properties for different applications: how bendy or rigid you want your plastic, whether it needs to be fire-resistant or resilient to the effects of sunlight, not forgetting dyes and pigments used to give the product the desired colour.
In food packaging or products designed for small children, there are stringent regulations of which chemicals can be included in order to reduce or mitigate the potential risk of exposure to toxins. However, this becomes problematic when you start to consider recycled plastics.
Plastics collected for recycling will have been made for a variety of different uses (just think what might be in your household plastic recycling bin) and contain a wide range of chemicals used in their manufacture. If you add to the equation the fact that plastics very easily absorb substances that they come into contact with (containers for pesticides, household cleaning products etc), then you have the potential for a cocktail of chemicals, none of which will be removed by the recycling process.
On top of this, studies have shown that other toxic chemicals can actually be produced during the physical process of recycling the material. As a result, these toxic chemicals can be transferred into products made from the recycled material, with evidence showing this includes food packaging and children’s toys.
Many of the chemicals routinely found in plastics have endocrine-disrupting effects: they can interfere with the way our body’s hormones work. This can cause a range of health problems, including cancer risk and fertility problems. These chemicals also impact on our natural environment, for example affecting the reproductive health of river fish stocks.
It would not be realistic to say that we should ban plastic production altogether (at least not in the short to medium term). Arguably, it makes sense to make some products from plastics where a lightweight, durable material is required. That said, substantially reducing our daily reliance on single-use plastics of course needs to be part of the solution.
The most important thing is that we control the use of toxic chemicals needed to manufacture the plastics and the first step in doing this is knowing what is actually in the materials in the first place. This information is difficult to obtain because it is commercially sensitive, but I would argue that increased transparency in the industry is needed.
I believe that recycling can also play an important role in solving the plastic crisis, but new regulation is needed to control the products that can be made out of recycled plastic where the impact of chemical risk is reduced, for instance putting it into construction materials or building foundations for new roads.
The other key aspect to this problem is innovation – we need to design new ways of making these materials where both the polymers and the chemicals used are more sustainable and, most importantly, non-toxic. Where the use of toxic chemicals is unavoidable then there should be more stringent controls over the end-of-life processing, and they should only be used when absolutely necessary.
The plastic problem is real and it is serious, but if scientists, industry, governments, and consumers all work together then we can overcome this crisis. We all have a crucial role to play.
Dr Charlotte Lloyd is a researcher and lecturer in environmental chemistry at the University of Bristol
