10 hottest questions on microplastics answered by Dr Simon Attwood, Director of Conservation and Science at WWF-Singapore.
It seems like plastic pollution and its impacts on our oceans, beaches and wildlife is one of the biggest environmental news stories at the moment.
Certainly, it’s a topic that has generated public concern, captured people’s imaginations, and has also set the media alight.
Headlines such as: “How did we let plastic bags get everywhere?”, “Recyclers cringe as Southeast Asia says it’s sick of the West’s trash” and“40 kg of plastic found in whale that starved to death” are becoming ever more commonplace and deal with the many aspects of plastic pollution from sources of pollution, to impacts on wildlife, to strategies for reduction and recycling. This enormous public and media interest are mirrored in the scientific community, where the number of scientific publications addressing plastic pollution has rocketed in recent years.
But in the past few days, there has been a subtle shift in the narrative that may propel plastic pollution out of the ‘environmental issue’ domain and into something of even greater public interest.
Suddenly, plastic pollution could be taking on a whole new level of gravity and looks like it is going to reach a new audience, one that isn’t necessarily influenced by issues perceived as focused on the environment.
Let’s look at two recent studies: 1) global study and campaign from WWF and the University of Newcastle in Australia which revealed we may be ingesting as much as 5 grams of microplastic per week found in our food, water, and air and 2) another study reported in the US last week that people may be consuming up to 121,000 microplastic particles from similar sources.
This looks like a potential game changer for plastic pollution.
We now have the publication of two studies examining plastic pollution from an angle that will resonate with a lot of people, and might just send a chill down the collective spines of decision makers in polluting companies and governments.
But what does it all mean and what can YOU do to address plastic pollution from the scale of straw to global impact?
How was “eating 5 grams per week” and “an analysis of 100,000 tiny pieces of plastic – or 250 grams – every year” calculated?
To get into this in detail would need several pages of text, but in essence, the researchers at the University of Newcastle used existing published research papers to determine particle sizes and weights, and the number of particles potentially ingested from different food and beverage sources. I asked this question to Kala Senathirajah from the University of Newcastle, one of the co-authors of the report; her response was: “Our study reviews the available literature from around the world and synthesizes it based on several conservative assumptions to estimate an average global ingestion rate by humans considering various exposure pathways. There was a need to make these assumptions to extrapolate and infill the data set due to the vast knowledge gaps, variability in sampling, variability in analysis, and even variability in reporting units. Several scenarios were investigated and it was determined that people could be ingesting a concerning 5 g/week.” The full methods and results have been submitted to an academic journal for publication.
Where is the plastic coming from?
In terms of our study, the researchers were only able to synthesise data from the available studies, so it was dependent upon what those individual studies had looked at previously. There have been published scientific studies on microplastic contamination in shellfish, tap water, bottled water, beer, salt, and a few other sources. So, they were the only ones that were available to use. In terms of the numbers of particles, a large proportion came from water, and the recent study in the US indicates that the proportion is particularly high for bottled water. There are also a lot of tiny fragments in the air that we breathe. In terms of where these tiny particles of plastic originally come from, it’s a real mix, with land, river and ocean pollution, threads from clothing, and fragments from vehicle tires as contributing factors. Consequently, there is no silver bullet in how we fix the plastic pollution issue.
5 grams a week sounds a lot! How do we get to this number?
Five grams a week is a pretty alarming number. Inevitably, there is a fair degree of variability of the actual amounts of particles reported across all the studies we assessed (the research team accounted for this variability in their analyses), and there will be considered global and cultural variability as well. But what we also need to consider is that the food and drink sources that we were able to include in the study (those that have been published in scientific journals) don’t include a lot of our basic staple foods such as rice, pasta, noodles, chicken, fruit, vegetables, highly processed foods. As more research is done, then those studies can be added to the future analysis and it’s highly feasible that the total amount ingested will go up. The researchers in Canada came to the same conclusion and calculated that their study only accounts for about 15% of the calorie intake of a recommended US diet. This is a real future priority for researchers to understand what the numbers might look like if some of these commonly eaten foods are included.
Plastic pollution is a global problem. How do we know if the food, water and air here in Singapore are contaminated with microplastics?
The study that the research team conducted and used as the basis for our campaign is based on globally-synthesised figures, so it’s hard to shrink those findings down to the issue in a single country at this stage. In order to really answer that question properly, we’d need research that actually samples individual food and drink items commonly consumed in Singapore, identifies the number of microplastic particles in each and then sees how much the average person consumes. For now, I think we have to assume that Singapore is around the global figure, as all the items assessed are readily consumed in Singapore.
People have been talking about the harmful effects of plastic pollution and microplastics for a long time. How is this report different?
A lot of the concern around plastic pollution really spiked with the Blue Planet II documentary – that brought the issue into the home and then related it to our daily lives and behaviours. But it was still largely an environmental issue, and often the environment comes a second-best to other issues, in part because we seem to easily or conveniently forget how dependent we are on a healthy, well-functioning environment. These two recent studies take plastics out of the ‘traditional’ environmental domain and move it into something far more relevant to the majority of people—their health! This changes the narrative a great deal from concern about the environment to more direct concern about oneself, family and friends.
If we might already be ingesting microplastics every day, why do people still think “one plastic straw can’t save the planet”?
A lot of people need to start somewhere as their first point of engagement, and drinking straws are one of those entry points. Of course, one drinking straw ‘won’t save the planet’, nor will 100 million. But the attitude change that can come with taking that first step can lead to behaviour change on other issues, a change in consumer decision-making to more sustainable choices, a change in engagement in political processes and so on. Now, if enough people do that, then that is where things start to add up, then positive change for the world and society we live in CAN start to happen. We need to start that avalanche of public opinion and support so that it adds up to millions of concerned voices that WILL move the dial on government policy and company behavior.
What is all this plastic ingestion doing to our health?
This is a really important area of research and application of that research. There are a lot of unknown areas, but one or two examples of recent research include increased risks of lesions in the respiratory system from airborne particles, and the potential that the very smallest particles could potentially interact negatively with the immune system. Other articles are indicating that the health risks and implications for people may not be so high, although levels of exposure may be key to this. However, there are still so many unknowns around the potential health impacts, that we are again collaborating with the University of Newcastle who is working hard on pulling all the existing research together and reviewing it as one massive body of work. That will really tell us where we stand, where the main risks are, and where research should be concentrated to fill the most urgent knowledge gaps.
Since plastic is non-biodegradable, won’t it be flushed out by our system?
Let’s see what the science says on this! There was a compelling Guardian article on “microplastics found in human stools for the first time” published in late 2018. This was based on some initial research by a group in Austria. So, we evidently do evacuate microplastic particles that enter us through food. The obvious next question is, do we evacuate all particles and what does this mean if we don’t? As with any emerging or new research area, there are differing views from different scientists. For instance, one study suggests that whilst microplastic particles may be unlikely to be absorbed into the body’s organs and tissues (they’re too large), much smaller nanoparticles may be absorbed with potential health impacts if exposure and absorption rates are very high. Meanwhile, another study that is a review of the evidence around (all aspects of) plastic and its known and potential impacts on human health suggests that there may be concerning health impacts, but there are still many uncertainties to be explored and addressed. It’s almost a cliche in science to say ‘more research is needed’, but in the case of micro (and nano) plastics and human health, this is undoubtedly the case.
Why can’t we ban plastics?
Plastics are incredibly useful materials – glance around as you’re reading this…how many materials can you see that are made of plastic? Now try to imagine if all that were banned, and what would we replace those items with? It is also helpful to make a distinction between durable, multi-use plastics and disposable single-use plastics. Even with single-use plastic items such as plastic bags, we need to look at what we’d aim to replace them with (e.g. paper bags), how feasible that is, what the environmental impacts of those other commodities would be.
A better way to look at plastics is that we need to reduce the use of single-use plastic, have truly effective recycling systems that reduce greenhouse gas emissions associated with plastic, and phase in alternative materials that have much lower environmental and (potentially) health impacts. There are a lot of innovators starting to work with more environmentally benign alternatives, so I think that we’re going to see some cool technological developments in this area. So, rather than aim to ban plastics and adopt such a binary view, we need a far more informed and nuanced approach. This could include encouraging governments to increase investments in better and more efficient collection and waste management, incentivising recyclable materials, and developing policies that create and enforce extended producer responsibility, so that the fate of plastics along the entire chain of production, to use, to disposal becomes more ingrained in company processes, operations, and strategies.
I get the severity of this issue. But so what? What can I do now?
It’s often mentioned what we can all individually do to reduce our single-use plastic consumption (e.g. avoid using plastic bags), ensure that what we do use gets recycled, and so on. However, there’s a bigger picture that we need to clearly and articulately communicate to our leaders, government ministers, authorities, local council officials and companies. And that is that we are seriously concerned about this issue and that we need to see a positive change in the areas of production, recycling, alternative materials, disposal, scientific research, and availability of reliable information. In Singapore, our Plastic ACTion (PACT) initiative is pushing local businesses to reduce plastic use, enabling a circular economy to develop and flourish. We are also working closely with them to review their plastic footprint and helping them switch to more sustainable alternatives.
This isn’t just about criticism, though – if your government is doing a great job on a recycling facility, let them know they’re doing a great job! If a company is using recycled materials and their competitors are not, favour that company! If they aren’t, then definitely convey to them that it’s not good enough and that this is a serious, planetary issue that we have here, and we need a rapid and global rethink and overhaul of how we’re producing, using and disposing of plastics.
An effective global response to the problem of marine plastic pollution requires international cooperation between countries to keep states accountable for the millions of tonnes of plastic that end up in the ocean every year. The first real step towards addressing this is for governments around the world to agree to a legally binding treaty on plastic pollution.
Find out how much plastic you could be consuming here.