No abstract

Microplastic fibers (MPFs) from textiles significantly contribute to the microplastic (MP) load in many environmental matrices and have been shown to negatively impact the organisms therein. Most fate and effect studies to date rely on pristine reference MP materials that have limited relevance compared with the partially degraded MP particles and fibers typically present in the natural environment. The current study aimed to develop and validate a rapid method to generate environmentally relevant polyester (PET) MPF reference material with controllable levels of degradation. Importantly, the method produced the same degradation products (terephthalic acid (TA) and ethylene glycol (EG)) as those generated during natural UV (sunlight) exposure of PET. Alkaline hydrolysis provided linearly increasing degrees of degraded PET MPFs over just a few hours, with full decomposition into molecular fragments occurring after 3 h. The extent of physical degradation was determined by scanning electron microscopy, whereas chemical degradation was quantified by measuring the production of TA and EG degradation products. The proposed accelerated hydrolysis degradation method is relevant for producing partially degraded PET MPF reference materials for use in fate and effect studies.

No abstract

No abstract

For many years it has been well known that tar was an available commodity in the Norwegian Iron Age, but until recently no production site or installation for such production was known. In this paper two recently discovered tar production sites, in south-eastern and mid-Norway respectively, are presented and discussed. Both are clay-lined funnel-shaped pits that are dug into the ground with an upper part where the wood was stacked and lit, and a lower part where the tar was collected in a container. The Norwegian tar production pits are similar to contemporary Swedish ones found in large numbers in mid-Sweden. The type is also known from the eastern part of Central Europe where they came into use a few centuries later than in Scandinavia.