The risks of micro- and nanoplastic particles

Microplastics. This topic is currently a subject of much discussion and reporting. We find it in the oceans, in the air and even in food products and cosmetics. However, there is still little profound knowledge about the amount of microplastics actually circulating and about how much is ending up in the human body through inhalation or ingestion. And we know even less about if and how microplastics affect our health.

"We are currently still lacking the necessary tools to measure and characterise micro- and nanoplastics, both in the environment and the human body", says Lea Ann Dailey from the Department of Pharmaceutical Sciences at the University of Vienna conducting research in the Imptox team: "Therefore, a main project goal is to develop suitable measuring methods. To achieve this goal, we will refine methods that initially come from the field of pharmaceutical development but could potentially also produce good results in environmental research."

Analysing the air at the beach

Lea Ann Dailey is an expert in the investigation of drugs that are developed to treat lung diseases. "With this background, I can use a wide range of methods to administer aerosols and investigate their deposition in the lung and the nasal area. This way, the EU project allows me to transfer my knowledge to the investigation of microplastics."

To do so, the researcher and her team visit beaches in Croatia and  the Lake Neusiedl – not to go on holiday but to take air samples, which are then classified according to their size using the 'Glaspimpinger', a special device to examine aerosols. "Using this device, we can actually see the amount of deposited microplastics in different areas of the respiratory tract. This differentiates our project from previous experiments around the world."

Simulation of the respiratory tract

The 'Glaspimpinger' device is usually used to characterise drugs for lung treatment. However, it is also able to separate aerosols which allows the researcher to see how much of them reach the nose and mouse areas, the upper respiratory tract or the deep parts of the lung. "The Glaspimpinger simulates the entire respiratory tract, is portable and can, therefore, be used anywhere", Dailey explains, "We are curious to see how the air quality in Croatia differs from the air quality at Lake Neusiedl. Our hypothesis is that sea air contains more micro- and nanoplastics, as the oceans are particularly affected by the flood of plastic."

Innovative measurements shed light on the amount of plastic

To be able to exactly measure the amount of plastic in the human body, Lea Ann Dailey uses a relatively new method from the field of materials research: "We will use a so-called atomic force microscope that is paired with an infrared spectrometer. It identifies the topology of the sample and, in connection with a chemical analysis allows us to identify the chemical composition of the sample", Lea Ann Dailey says, "Together with our cooperation partners, we are the first research team worldwide to investigate this method for the analysis of smallest particles of micro- and nanoplastics in samples from the environment. So, we are actually using cutting-edge technology."

The human lung is, by nature, well equipped to expel small particles, such as dust particles, that enter the upper respiratory tract, for example by coughing. Only particles that reach the deeper lung and stay there can cause irritation. "We know that plastic is very persistent, but at the same time plastic particles cause less irritation than, e.g. mineral dust since they are generally rather inert, i.e. not very reactive. Even so, plastic attracts other molecules to its surface. This could, we assume, worsen allergies", says Lea Ann Dailey.

How much plastic can the human body tolerate?

Therefore, the researchers working on the Imptox project primarily aim to investigate whether micro- and nanoplastics attract allergens, in particular protein components.  If so, they want to find out whether this actually increases the allergenic potential. Moreover, Lea Ann Dailey will examine whether microplastics reaching the respiratory tract can influence the allergenic potential of certain components of pollen.

The researcher is not yet able to assess the actual effects of circulating micro- and nanoplastics on human health: "As a society, we can only assess the risks associated with microplastics once we know exactly how much plastic the human body is exposed to and where this plastic deposits. And this is, in turn, closely related to the following important question that my team and I are investigating in our sub-project: What is 'attached' to the plastic we inhale?" (td)