Should I worry about microplastics?
Microplastics are everywhere. These tiny pieces of plastic – the usual definition is anything less than 5mm long – are a byproduct of the overproduction of synthetic polymers, and there is mounting evidence that they are infiltrating the entire ecosystem. A recent study found them in 90% of protein species sampled by researchers during one study from 2020 found them in fruits and vegetables. Another study published this year suggests that bottled water can hold up to 2.5kg of water 100 times the amount of plastic particles previously thought, and some studies have even found microplastics in prenatal human placentas. So is this an unstoppable problem? Are there health consequences that we are just beginning to see? And if so, is it already too late to do something about it?
To start with the bad news: yes, the problem is worse than previously thought. “Everyone knew there were microplastics in our seawater and on our beaches, but we are now finding them in the freshwater system and even as far away as the Arctic,” said Prof. Catherine Wilson, an expert in microplastics at the School of Engineering. Cardiff University. “This raises questions about how they are transported by air. We also see – because we use recycled sludge, a nutrient-rich waste product from sewage treatment, as fertilizer in agriculture – that microplastics are recycled in the environment, which can mean they accumulate in the soil of agricultural land. ”
How bad are microplastics for humans? There are two clear mechanisms by which microplastics can harm us: either by chemically disrupting the normal functioning of our body systems, or by accumulating in sufficient quantities to block our circulatory, respiratory or digestive systems. For example, the increased risk of cancer is a major concern, but it is not clear how concerned we should be. “Links to the carcinogenic potential of microplastics and nanoplastics, which are barely visible to the eye even under a powerful microscope, have been demonstrated in vitro (laboratory test tubes or similar) in human cells and in vivo (in a living body) for animal and plant models,” says Prof. Jo Cable, Head of Department, School of Biosciences, Cardiff University. “But it is worth saying that the effects in most of these studies were caused by concentrations of plastic that were much higher than the concentrations detected in the bloodstream in some of the cases. most recent studies.”
It is also not clear whether microplastics have a significant effect on, for example, the production of immune cells or appetite, although all these possibilities are worrying. “Further research is needed to determine the effects of this level of exposure – and whether microplastics continue to accumulate or are eventually expelled from our bodies,” says Cable. “We also need to understand whether better alternatives are possible – for example, the Plastic Fish project at Cardiff University is investigating whether bio-based plastics and associated additives that are often marketed as ‘greener’ than traditional plastics are in fact healthier for the environment and organisms if and when exposure occurs. Evidence is mounting that this may not be the case.”
What can we do? Unfortunately, this is a social problem: the ubiquity of microplastics means there is little chance of avoiding them. Plastics are an essential and often life-saving product, but we have been using them unsustainably for years and have left a legacy for future generations that can be difficult to address. At a global level, we need to switch to plastic products that are either biodegradable – that is, break down naturally – or are structurally easier to chemically recycle; and consumers and businesses should be encouraged to embrace them. It’s not an easy problem to deal with, but because it probably affects everyone who swims, eats or breathes, it affects us all.