Interlaboratory evaluation of the assessment of arsenic bioaccumulation from field collected sediments using Hexagenia spp

Abstract

Standardized bioaccumulation testing of aquatic organisms is essential to understanding the impact of historical contamination on the quality of water and sediment. A standardized 28-d laboratory bioaccumulation method with a freshwater burrowing mayfly, Hexagenia spp., has been developed and internally validated by the Ontario Ministry of the Environment and Climate Change (MOECC). An interlaboratory comparison was conducted to assess the precision of this method. Field-collected sediment contaminated with arsenic was chosen for the present study. Control and test sediments were subsampled and sent to 6 laboratories to perform the bioaccumulation test. One laboratory failed to meet the control survival criterion of ≥80%. When results of this laboratory are removed from the arsenic accumulation assessment, the mean interlaboratory variability (expressed as coefficient of variation) of the arsenic whole-body concentration is reduced from 44% to 24% in the test sediment-exposed Hexagenia spp. There was no significant interlaboratory difference between the Hexagenia spp. arsenic accumulations. While improved culturing and organism holding guidance may increase laboratory success, the MOECC Hexagenia spp. bioaccumulation test method has tight biological method precision when the control survival criterion is met. Environ Toxicol Chem 2016;35:2448-2455. © 2016 SETAC.

Sediment ecotoxicology—Current research on laboratory methods: An introduction

“…In the fourth article (Taylor et al ), the authors detail the internal method validation assessment of the ability of Environment Canada's proposed 42‐d Hyalella azteca reproduction test method in sediment to meet control validity criteria. In the fifth (Ivey et al ) and sixth (Watson‐Leung et al ) articles, the authors report the results of interlaboratory testing (with Hyalella azteca and the burrowing mayfly Hexagenia spp.) and demonstrate the value of cross‐laboratory performance comparisons to assist with revising standard methods to include key method requirements that influence test outcome.…”