Uranium toxicity to aquatic invertebrates: A laboratory assay.
Environ Pollut
; 239: 359-366, 2018 Aug.
Article
in En
| MEDLINE
| ID: mdl-29674214
ABSTRACT
Uranium mining is an environmental concern because of runoff and the potential for toxic effects on the biota. To investigate uranium toxicity to freshwater invertebrates, we conducted a 96-h acute toxicity test to determine lethal concentrations (testing concentrations up to 262â¯mgâ¯L-1) for three stream invertebrates a shredder caddisfly, Schizopelex festiva Rambur (Trichoptera, Sericostomatidae); a detritivorous isopod, Proasellus sp. (Isopoda, Asellidae); and a scraper gastropod, Theodoxus fluviatilis (Gastropoda, Neritidae). Next, we ran a chronic-toxicity test with the most tolerant species (S. festiva) to assess if uranium concentrations found in some local streams (up to 25⯵gâ¯L-1) affect feeding, growth and respiration rates. Finally, we investigated whether S. festiva takes up uranium from the water and/or from ingested food. In the acute test, S. festiva survived in all uranium concentrations tested. LC50-96-h for Proasellus sp and T. fluviatilis were 142â¯mgâ¯L-1 and 24â¯mgâ¯L-1, respectively. Specimens of S. festiva exposed to 25⯵gâ¯L-1 had 47% reduced growth compared with specimens under control conditions (21.5⯱â¯2.9 vs. 40.6⯱â¯4.9⯵g of mass increase animal-1·day-1). Respiration rates (0.40⯱â¯0.03⯵g O2·h-1·mg animal-1) and consumption rates (0.54⯱â¯0.05⯵g⯵g animal-1·day-1; means⯱â¯SE) did not differ between treatments. Under laboratory conditions S. festiva accumulated uranium from both the water and the ingested food. Our results indicate that uranium can be less toxic than other metals or metalloids produced by mining activities. However, even at the low concentrations observed in streams affected by abandoned mines, uranium can impair physiological processes, is bioaccumulated, and is potentially transferred through food webs.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Water Pollutants, Chemical
/
Uranium
/
Toxicity Tests, Chronic
/
Aquatic Organisms
/
Invertebrates
Limits:
Animals
Language:
En
Journal:
Environ Pollut
Journal subject:
SAUDE AMBIENTAL
Year:
2018
Document type:
Article