Recently, new progress in research on the biomagnification of per-and polyfluoroalkyl substances (PFASs) was made by Academician Jiang Guibin's Lab at School of Environment, Hangzhou Institute for Advanced Study (HIAS), UCAS. This research unveiled the biomagnification of short-chain PFASs, alternatives to traditional PFASs, in the terrestrial food chain for the first time. The related paper entitled "Trophic Magnification of Short-Chain Per- and Polyfluoroalkyl Substances in a Terrestrial Food Chain from the Tibetan Plateau" was published in theEnvironmental Science & Technology Letters, a top journal (CAS Zone 1) in environmental sciences, and featured on the supplemental cover of the journal.
Figure 1 Paper on the Cover and Trophic Magnification of PFASs in Forage-pika-eagle Food Chain
PFASs have been widely used in production and life due to their excellent chemical stability and surface activity. Over long periods of use, they have also been found to cause certain risks to the ecological environment and humans. Long-chain PFASs, like perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), are persistent, bioaccumulative and toxic substances that have been listed as persistent organic pollutants (POPs) under the Stockholm Convention. As a result of control over long-chain PFASs, short-chain PFASs like perfluorobutanoic acid (PFBA) and perfluorobutanesulfonic acid (PFBS) are widely used as their alternatives. Compared with traditional long-chain PFASs, short-chain PFASs are also persistent and highly volatile, and more likely to be transported via air over long distances. A large number of studies have shown that long-chain PFASs have a biomagnification effect in the food chain, while short-chain PFASs are generally considered unable to biomagnify due to high water solubility. However, current studies on the trophic transfer of short-chain PFASs are limited to the aquatic food chain and there is no sufficient data on the trophic transfer of short-chain PFASs in the terrestrial food chain.
Targeting the typical terrestrial food chain composed of forage, pikas, and eagles in the Namsto Lake region on the Qinghai-Tibet Plateau, this research has explored the occurrence and trophic transfer rule of long-chain and short-chain PFASs in this terrestrial food chain. PFASs have been detected in the soil, forage grasses, muscles of pikas and eagles and feathers of eagles on the Qinghai-Tibet Plateau. PFBSs and PFBAs' biomagnification factors reach the highest levels between forage grasses and pikas. This indicates that short-chain PFASs are more likely to concentrate between grasses and pikas, while long-chain PFASs are more likely to concentrate between pikas and eagles. In addition to long-chain PFASs, PFBAs and PFBSs also have high biomagnification effects in the forage-pika-eagle food chain, with trophic amplification factors of 5.96 and 5.11, respectively (Figure 1). The biomagnification of short-chain PFASs in the terrestrial food chain may be related to their high KOA (octanol-air partition coefficients) and the transformation of precursors.
This research is the first to find the biomagnification of short-chain PFASs in the terrestrial food chain. According to the hints in this paper, these short-chain alternatives may pose certain risks to the terrestrial ecosystem and the extensive use of short-chain PFASs may also cause potential harm to the health of humans standing at the top of the terrestrial food chain. Therefore, evaluating the bioaccumulation of new chemicals or alternatives to traditional chemicals in terrestrial ecosystems is an integral part of a chemical safety assessment before they are mass-produced and put on the market.
The first author of this paper is Huang Kai, a postdoctoral researcher at HIAS's School of Environment, and the corresponding author is Researcher Fu Jianjie; HIAS's employee Fu Jie and students Zhou Wei, Gu Luyao and Hu Boyuan participated in some of the work. The work was supported by the Second Tibetan Plateau Scientific Expedition and Research (STEP) program, and the programs of the National Natural Science Foundation of China and the Youth Innovation Promotion Association of the Chinese Academy of Sciences (CAS).
Article link: https://pubs.acs.org/doi/10.1021/acs.estlett.1c01009
Text by | School of Environment
