Spectrochemical sensing of airborne nanoplastic particles

Worldwide plastic pollution is on the rise and poses a threat to nature, the environment, and health. Since the 1970s, our dependence on plastic in everyday life has surged. Annually, around 400 million tons of plastics are produced, with a substantial portion ending up as waste in oceans, rivers, lakes, and on land. In 2019 alone, 22 million tons of plastic waste were released into the environment. The plastic pollution problem extends beyond visible waste. Over time, larger plastic items can fragment into micro- and nanoplastics in our environment. These are very small particles that are increasingly accumulating in natural systems worldwide, posing a significant global environmental challenge. In addition, these micro- and nanoplastics can also enter our environment directly, flowing into rivers through wastewater streams (containing residues from cosmetic products, etc.), or dispersing into the air via tire wear abrasion from vehicles. Nanoplastics are characterized by their size of less than 1 m, which is a size range comparable to some of the smallest bacteria or viruses and cannot be seen with the naked eye. They have attracted worldwide attention because their small size and large specific surface area facilitates their uptake by organisms and their distribution throughout the body. These tiny particles pollute aquatic and terrestrial environments as well as our air. The atmosphere acts as a global transport medium that can carry plastic particles to the most remote areas of the world. Growing concerns about the potential negative impact on the economy, wildlife, and human health are driving the in-depth study of this issue. However, due to their small size, detecting nanoplastics in the environment is a significant challenge. In our research project, we develop an analytical method that enables the non-destructive detection of nanoplastic particles to determine their concentration and mass distribution from air samples. We employ a combination of microscopic and spectroscopic methods, with the high-resolution interferometric scattering microscope serving as the heart of the method for the precise analysis of these nanoplastic particles.