3 years ago

Radioactive cesium contamination and its biological half-life in larvae of Stenopsyche marmorata (Trichoptera: Stenopsychidae)

Takeshi Nomoto, Takeshi Fujino, Takashi Gomi, Shota Kobori, Masaru Sakai

Abstract

The total radioactive Cs concentration in final-instar Stenopsyche marmorata larvae from the Mano River, Fukushima Prefecture, in 2013 was found to be >1000 Bq kg−1 in dry weight. The concentration of radioactive Cs in the river water itself was on the order of 0.01 Bq kg−1, while its concentration in drifting fine particulate organic matter (FPOM) was on the order of 10,000 Bq kg−1 in dry weight. When excretion experiments were performed in the summer and winter, significant decreases in the Cs concentrations in the whole body of S. marmorata were observed in both seasons. The biological half-life of Cs-137 was 5.3 and 8.8 h for the nonwintering generation and the wintering generation, respectively. Another elimination test using a stable Cs solution was performed, and the Cs concentration was observed to decrease rapidly to 7.5% of its original level in the digestive tract of S. marmorata after 72 h, but stable Cs remained in muscle and extra-alimentary tissue of S. marmorata. As the total radioactive Cs in the water was quite low, its concentration in S. marmorata from the Mano River reflects the fact that it feeds on FPOM. The radioactive Cs concentration in the FPOM significantly declined in 2015, but a corresponding decline was not observed for S. marmorata. We therefore infer that ultrafine particulate matter such as suspended vermiculite clay is strongly contaminated with radioactive Cs, and that this radioactive Cs passes continuously through the digestive tract of S. marmorata.

Publisher URL: https://link.springer.com/article/10.1007/s11355-017-0339-5

DOI: 10.1007/s11355-017-0339-5

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.