The scientific goal of our expedition is simple. The snow on the surface of the glaciers we're walking on acts as a repository for any small plastic particles floating in the air. We collect the snow and measure the plastic. What sort of plastic is it? Does it come from bottles, car tyres or clothing? How big are the particles? Are they fibres or have they been broken down into tiny nano-plastics?
Say 'microplastics' to most people and they will probably conjure up an image of plastic bags floating in the ocean. Sea-borne plastic pollution may be obvious and visible, but it may also be something of a red-herring in terms of its ultimate impact. We shouldn't overlook airborne plastic pollution just because we can't see it.
In 2020, a collaboration between researchers in Norway and Austria suggested that oceans and rivers may not be the most important mode of transport for plastic pollution. They showed that the air we breathe can be a very efficient way of transporting micro- and nano-plastics around the world.
The key point is that plastics are known to break down into smaller and smaller particles and these particles are known to be transported over long distances by the wind. Sources include personal care products, road markings, textiles and tyres although but it is not yet clear which are the most important.
Micro- and nano-plastics have been found in the human body although it is not yet known whether they are absorbed primarily by eating, breathing or through the skin. In vitro evidence and animal studies show various adverse effects and suggest that it may be contaminants adsorbed onto nanoplastics and hitching a ride into the body which are most harmful. At the time of writing there is no direct in vivo evidence of harm in humans.
In 2019, Italian scientists from the University of Milan detected microplastics on Alpine glaciers for the first time. Wearing cotton clothing and wooden clogs to avoid contamination, the research team sampled the surface of the Forni glacier 100km north of Milan and found about 75 pieces of plastic per kilogram of dried glacial debris. This showed that, far from being a pristine snowy wilderness, there is plastic pollution in the Alps which can only have come in on mountaineers, skiers or the wind.
In 2020 a group of researchers, including Dušan Materić who leads our science team, published a new technique for measuring micro- and nano-plastics in Alpine Snow. This is 100x more sensitive than previous methods and, crucially, allows us to take small jam-jar-sized samples rather than large ice cores. The point about this is that the samples can be carried and, for the first time, it is possible for a small mobile team to take samples from a number of different places. Besides, mountaineers and climbers love shiny, lightweight equipment!
If, as seems likely, it is definitively proven that plastic pollution degrades into small particles and that these are harmful to human life, then we will be in the same position with plastic pollution now as we were with global warming when the evidence first became definitive in the 1950s. It would make sense to do something about this sooner rather than later. Having waited over half a century to take action on climate change, the problem and the economic costs of dealing with it are bigger than they needed to be. Why wait fifty years to deal with plastic pollution and end up having to filter the atmosphere of the entire planet?
To do anything about plastic, we need to know where to focus our efforts. In other words, what sorts of plastic are most problematic and where do they come from? Is it tyres, toothpaste or textiles? Is most of the pollution coming from primary sources or, for example, is the mechanical recycling of plastics actually contributing to the problem by helping to break down relatively innocuous macroplastics into potentially harmful nanoplastics? This is what we intend to find out.