re-usable cups

Micromanaging plastic waste

Thames, South bank, London Eye, plastic pollution, Thames21, PLA
Each year Thames21 and the Port of London Authority remove 200 tonnes of waste from the Thames. How much more gets washed into the sea?

Five items make up 2/3 of all lightweight identifiable waste collected from the Thames each year. These items make their way either through being dropped, sometimes deliberately littered, or through another path, into the river where, without litter picks, they are eventually washed out to sea. Part of the estimated annual ~10m tonnes of plastic waste entering into the oceans, they end in one of the gyres of the oceans, vast expanses of sea covered by floating rubbish.

Only much of this waste doesn’t. Or at least not as much as we think should do and we don’t know why. Despite the fact that there is an estimated 250 000 tonnes of waste floating in places such as the North Pacific Gyre, this is not as much as is expected. In fact, the visible waste makes up only a few percent of the waste that is expected to be there. Where is the rest of the waste, and what does it have to do with physics, or indeed coffee?

One of the ‘top 5’ items found in the Thames (coming in at number 4) is take away cups. This is followed closely by take-away containers. This means that our behaviour on leaving cafes, restaurants (and pubs) is affecting the litter that ends up in the river. And this is without counting the fact that food wrappers and drinks bottles (including water bottles) are two of the other worst offenders. It is not necessarily that people are deliberately throwing the items onto the pavement as they walk (though there is that too of course). The charity Thames21 that organises river-side clear ups and litter picks also thinks that some of the waste is coming as a result of people trying to put items into over-filled bins or so-called “tidy litterers“. But the truth is, they don’t really understand the route that many of these items take before entering the river system.

Discarded litter, can holder, litter
Some litter that finds its way into the oceans is merely discarded like this 6 pack can holder. Reducing this getting into the oceans is helped by fewer people littering, more people picking up what they see discarded and changes to the product itself.

It is a significant problem for us now as many of us are trying to support local restaurants or cafes by ordering take away and even when a place has drink-in space, often it is single-use disposable cups that are used. Part of this is understandable. There is a hygiene concern, even if there are counter-arguments that re-usables are safe to use in these times of Covid-19. But I don’t want to trivialise this concern, partly because people are making very hard decisions about how to keep their businesses going or earn enough to pay the next set of bills. If there is any doubt about the safety, it needs to be considered holistically by those running and working in the businesses and not those like me able to work from home and able to get delivery or pop-in and pop-out (and, in fairness, it is easy to see from a barista’s point of view that handling an untouched single-use cup and giving it in a contactless way to a customer is safer than receiving their re-usable container in whatever state of cleanliness it is presented in).

This part seems a question of balance. Balancing the need for economic support with the concerns of the single-use plastic problem. Do the places that you frequent use recycled (and recyclable) plastics or compostable ones? If the latter, is there a compost bin within the cafe to help with the disposal of these? Ultimately, is your take-away coffee going to help the business or are there other items that you can purchase that don’t require the same amount of packaging.

These are considerations with no easy answers which leads to the second approach that you could take. In non-Covid times, charities such as Thames21 are always looking for volunteers to help with clean ups and to get involved in counting the types of litter that find their way to the rivers. Becoming a ‘citizen scientist’ in this way helps to quantify the amount of waste entering our rivers but it also helps Thames21 and the river authorities to understand how the waste gets there in the first place. Why are our river banks so filthy?

Coot nest, plastic waste, Grand Union Canal, litter, plastic pollution, effect on wildlife
A coot building its nest with twigs and litter, including plastic litter, on the Grand Union Canal in London in 2019.

But then the last question. If we know that so much waste is getting into our river, and we know that this is being replicated around the world, why is so little of it making its way to the gyres? What is happening to it?

This affects, to some extent, what we do about our plastic behaviour – the decisions we ultimately make about whether to have a take-away coffee or whether to buy a disposable or re-usable face mask (or even make one). One of the explanations is that the majority of the plastic is becoming micro plastic (<5mm size pieces) or even nano plastic and so sinking into the seas rather than floating on the surface. These micro plastics are the result of the break-up of larger items by UV and micro organisms at sea and also the direct pollution of micro plastics into the sea by clothes being washed or from cleaning products etc. Indeed, the Thames21 citizen scientists discovered micro plastic pollution at 20 out of 21 sites along the river bank in a recent litter survey. A different explanation is that the plastics that are entering our seas today take years, even decades to reach the gyres which are made up of plastics from the 1970s and similar aged pieces. Both explanations mean that we need to stop the pollution at source, but if it is the former, there is not so much point in cleaning up the gyres by pulling the large litter out – the majority of the plastic that is in the oceans is actually underneath what is visible.

Refill station
Water stations and refill bottle. Many of these have been designed to avoid any contact between your reusable bottle and the tap allowing a safe way of travelling with reusables.

How can we determine what plastic waste goes where? Well, we can increase the modelling of ocean currents to improve our ideas about how waste is transported from source to gyre, but we can also try to have a look from space, from the satellites that are monitoring other aspects of our behaviour on Earth. Now it turns out that it is not easy to see plastic from space because with many of the techniques we would use, such as radar, plastic and water ‘look’ very similar. But one thing that that the satellite data has shown is the fact that there are peculiarly calm regions of sea near the gyres. Calm sea looks different from choppy seas in the same way that the light reflected off your coffee looks different if you are sitting with it calmly or if you are running with it and it is sloshing around the cup. But the connections go a bit further than this. The reason for the calm is because of surfactants on the surface of the seas. These surfactants (like soap) ‘calm’ the waves in much the same way as oil calms the waves. It doesn’t take much surfactant to cover the surface of a large area of water as a consideration of how much oil covers the surface of your coffee can tell you.

The surfactants are produced by microbial activity, the result of small bits of plastic (micro plastics) having been colonised by microbes before it sinks. The calm regions of the sea may therefore be indicating areas of hidden micro plastics and demonstrating the depth of the problem of single use plastic waste.

What does this mean for your take-away coffee, your Deliveroo order or your disposable mask? A recent study suggests that it is imperative that we take a combined approach, both as consumers, and as producers, reducing, reusing, recycling and changing the system. But on a personal level of course, some answers are clearer than others. Having an idea of the size of the problem, and the things that we can do to mitigate or understand it, may help us to navigate this plastic minefield.

Pushing it at Lever and Bloom, Bloomsbury

Lever Bloom coffee

Lever and Bloom under a blue sky.

Does a take-away need to be rushed? A coffee so quick that there is ‘not enough time to prepare a flat white’? Are we always so preoccupied with the distractions of our day that we consume our coffee merely for the pleasant caffeine kick that it provides?

Lever and Bloom in Bloomsbury is a great example of why this does not have to be, indeed should not be the case. Since 2015, Lever and Bloom have been operating out of a cart on Byng Place close to UCL and a number of other research institutes. The character of the surroundings really does affect the space and both times I have been to Lever and Bloom I have either met interesting people in the queue or overheard snippets of intriguing conversation about history I know nothing about.

Coffee Bloomsbury reusable coffee cup

Long black in a keep-cup and telephone box in Byng Place.

It is easy to spot the coffee cart in the corner. Firstly, it is bright red and quite eye catching but secondly because of the queue forming in front of it. Don’t be put off though, the queue moves very quickly so you won’t wait long even if you are in a rush. Queueing however does give you an opportunity to peer into the cart. Space is used extremely efficiently. with each piece of equipment  apparently having its own perfect home. It reminded me of a childhood game of trying to fit in as many objects as possible into a matchbox. A cabinet on the table in front of the cart displays cakes including cinnamon rolls (sadly sold out by the time I arrived in the afternoon). It was also nice to see the number of people ahead of me in the queue who were using re-usable cups.

The lever of the name refers to the (Izzo Pompei) lever espresso machine that is used on the cart. It was fascinating to watch the ground beans being carefully tamped and the lever being pulled to prepare the espresso. Although there is some debate as to the optimum water pressure needed for preparing an espresso, the standard pressure is 9 Bar; water is pushed through the tamped grinds at nine times the atmospheric pressure at sea level. Watching these espressos being prepared reminded me of preparing ceramic samples of an interesting magnetic material a few years ago. We were interested in the electrical properties of a class of materials called manganites. To prepare the materials for measurement we first had to grind the pre-cursor powders (but with a pestle and mortar, no burr grinders) and then, after a couple of further preparatory steps, press them into a pellet ready for firing in the oven. The machine used for pressing the pellets had a lever, not dissimilar to that on the espresso machines and yet, the pressure that we used for the pellets was roughly 1000 Bar. This high pressure was needed so that dense pellets of manganite material would be formed when we heated it in the oven (typically at 1200 ºC). Just as a good espresso depends on the pressure and then the temperature and time of extraction, so the properties of the pellet would be affected by the pressure and then temperature and time of firing in the oven.

Portland Stone fossils

Fossils in Portland Stone. It is astonishing what is revealed when you slow down and notice the buildings around you.

Similar effects affect the rocks of the earth, something that is particularly visible in the area around Lever and Bloom. A geological walking tour around Byng Place, Tottenham Court Road and towards the British Museum illustrates this particularly well. Behind Lever and Bloom, the church of Christ the King is built from Bath Stone. An oolitic limestone, this type of rock is formed of compressed sand and bits of shell. Much as the manganite samples of my study before they were fired in the oven but of a more interesting colour. Heading towards Gower St and the impressive UCL building is made of Portland Stone. Another limestone, this building material is a goldmine for urban fossil explorers. Continuing the walk, on Tottenham Court Road, the Mortimer Arms pub is fronted by quartzite while Swedish Green Marble adorns 90 Tottenham Court Road. Quartzite and Marble are both types of metamorphic rock, formed by pressing together different precursor materials at high pressure and temperature. Other types of marble can be seen on the tour, suggesting the influence of pressure and temperature of formation on the rock structure as well as the type of precursor rock.

It would seem that such a walking tour is perfectly timed for a longer style of coffee, perhaps a latte (in a re-usable cup of course) from such a centrally located place as Lever and Bloom. And of course, assuming you are using a re-usable, there is even more to ponder. The pressure and temperature during the manufacture of the re-usable cup would have affected the properties of the cup (or in my case, glass).

Let me know if you spot any interesting rocks or fossils during your time at Lever and Bloom but whatever you do, I hope that you can enjoy your coffee and then slow down to enjoy it a bit more.

Lever and Bloom is at Byng Place, WC1E 7JJ

Would you like plastic in that?

Straws with viscous liquid (milkshake) in them

Do you need that straw?

Plastic Free July starts in just a few days time. Each year this initiative encourages us to eliminate, or at least reduce, our use of single use plastic throughout the month of July. It is a great way to increase our awareness of our plastic use by attempting not to use any.

There are numerous reasons that we may want to reduce our plastic consumption. In addition to the problems of litter associated with plastic waste, there are problems for wildlife caused by ingesting our rubbish. Even if we dispose of it responsibly, plastic takes a long time to degrade. It is thought provoking to consider that the take-away cup that we discarded yesterday may still be lying in some landfill site years after we have forgotten about drinking that coffee. So what can be done about it and what are the specific issues for coffee drinkers?

air valve, plastic, environmental coffee packaging

Air valves and metallised plastic are common packaging materials for freshly roasted coffee, but can we avoid them?

One way to start to reduce our dependence on single use plastic is to understand how much we actually use on a day by day basis. Registering for a plastic free July is one way of doing this. As a result of attempting a Plastic Free July last year, I have found some plastic-free habits that have stuck with me all year. Loose leaf tea is one such improvement (teabags can also contain plastic). Although initially it seemed a bit of a pain to use a basket to brew the tea, as I kept with the habit I found it easy to compost the tea leaves after making a brew and the tea tastes better too. Things like shampoo bars and tooth ‘paste’ tablets (from Lush) have also been better and longer lasting than similar products packaged in plastic bottles.  Although some plastic habits are hard to break, living as plastic free as possible for one month did deepen my awareness of the plastic that I take for granted.

But perhaps living plastic free for a month is too daunting? An alternative challenge sadly emphasises just how linked coffee drinking can be to single-use plastic consumption. The Top 4 challenge asks you to eliminate, just for July, the target take-away items. Of these 4, at least 2 (and arguably 3) are linked to coffee drinking or cafés. The top 4 are plastic bags, bottles, take-away coffee cups and straws. Could you avoid these for just one month? Take the challenge.

blue tits, mint water, mint infusion, mint leaves in water

Enjoying a glass of water in a cafe can be better than running with a bottle of water anyway.

If you are ready to go plastic-free in your coffee habits, here’s a list of where we frequently encounter single-use plastic while drinking in cafés or even at home, together with suggestions of how to avoid the plastic where appropriate. Please let me know in the comments section below if you can think of further examples (and how you are avoiding them either in July or more permanently).

  • Disposable take-away coffee cups – get and use a re-usable one. You can find a helpful comparison of different types of re-usable coffee cups on Brian’s Coffee Spot.
  • Tea bags – yes they can contain plastic, see more information here. To avoid them, get hold of a metal tea basket, or even a tea pot and strainer and start investigating loose leaf tea.
  • Water bottles/soft drinks bottles – if in a café, why not enjoy the moment by staying with a glass of water rather than grabbing a bottle? If you are in a hurry though, a flask (such as klean-kanteen) is a great investment. In some parts of London (and perhaps elsewhere?) chilled tap water is available on tap for use in re-usable bottles
  • Air valves on your roasted coffee bag – do you really need these? The Nottingham based coffee roaster, Roasting House, did a taste test on freshly roasted coffee packaged with and without air valves, you can read their results here. If the coffee roaster that you normally purchase coffee from insists on using air-valves, why not write to them to request that they reconsider their packaging or try a more environmentally conscious roasting company to see how their coffee compares?
  • Coffee packaging – What type of material did the last bag of coffee that you purchased come in? Chances are it was metallised plastic, why not find a roaster with alternative packaging? Who knows, you may find another great coffee roaster to add to the ones that you buy from.
  • Straws – why would you use these anyway?
  • Milk bottles – Some companies still supply milk in glass bottles, otherwise you could consider non-dairy milks that can be home-made such as oat or almond. Some cafés also offer home-made non-dairy milks which would be a way of going plastic free while enjoying a latte in a café.
  • Cakes/sandwiches packaging – in larger chains these may come in packaging. However, if they are coming in packaging then they are not likely to be that fresh, find somewhere else with better cakes or sandwiches or make your own!
  • Spoons/cutlery
  • Packaging for sugar etc – ditching the sugar is supposed to be good for you anyway. If you cannot resist sweetening your coffee, try to find a sugar that is packaged in paper rather than plastic.
  • Washing up liquid – switching to a re-fillable washing up liquid reduces (but does not eliminate entirely) plastic waste.

Good luck if you take the challenge. There are still a few days left to plan how you can reduce the plastic in your life before the start of Plastic Free July 2017. Please do let me know how your attempts to be plastic free go and whether you find, as I did last year, that you enjoy your tea (or even coffee) more when you do so.