Should We Worry About Nanoparticles?

Nanoparticles have interesting properties. These 'mini-machines' are tiny, being less than 100 nanometres (a nanometre is one billionth of a metre). Nanoparticles exist naturally (e.g. in spider silk) but have also been made synthetically (like nanosilver, used to coat medical breathing tubes and bandages). Nanoparticles have been added to cosmetics, curtains, drugs, fabrics, foods and medical equipment, with apparently no attempt to assess their safety. Some scientists now worry that nanoparticles might pose a greater environmental threat than microplastics (https://www.theguardian.com/environment/2022/apr/25/nano-state-tiny-and-now-everywhere-how-big-a-problem-are-nanoparticles). When household items are washed, recycled or thrown away, the synthetic nanoparticles they are coated with, may be released into the environment. For example, synthetic nanoparticles from odour-resistant socks and sunscreen have been found in seawater. Some of these compounds, have negative effects on fish and crustaceans. Coating items with nanosilver, to make them less prone to odour, has resulted in the development of silver-tolerant bacteria. This echoes the story where the over-use of antibiotics has led to the development of 'superbugs'. One gets the impression that synthetic nanoparticles with 'magical' properties are developed. These are then incorporated in commercial applications, without even considering any potential environmental problems. Rigorous safety testing might slow down the profits. Nanoparticles, however, have very different properties to larger chunks of their parent compounds. They really are different!