Evaluating 40 years of bioaccumulation testing with Lumbriculus variegates

To evaluate the aquatic risk of a contaminant an understanding of both exposure and effects are needed. Traditionally, chemical concentrations in a media (exposure) are compared to toxicity bioassays with the media (effects) to understand risk. These evaluations, however, take a considerable amount of interpretation as each determination is conducted separately. The use of bioaccumulation assays in aquatic assessments are an invaluable tool in linking the two methods as accumulation of chemicals in biota provided a direct link from exposure to effects. This is especially true for the assessment of sediments (which many have speculated are the most important route of exposure for benthic organisms), as bioaccumulation assays take into consideration both ingestion and dermal adsorption exposure routes. Although sediment bioaccumulation assays started in the mid- to late 1980s, it wasn’t until the early 2000s that the U.S. Environmental Protection Agency chose Lumbriculus variegatus as the model freshwater organism for assessing bioaccumulation in sediments. The current study evaluated published papers from 1980 to 2019 pertaining to sediment bioaccumulation and L. variegatus. Of the papers that met the criteria (161 in total), a closer analysis was also conducted to analyze the temporal trends in chemicals or methods explored by each paper over the years. In this review, we explore the differences between field and laboratory spiked sediment bioassays, the trends for bioaccumulation testing for individual and chemical classes, the types of bioaccumulation assessments and kinetic modelling utilized, as well as more in-depth assessments of individual chemicals, such as benzo(a)pyrene. Overall, the goal of this review, was to better understand not only the current data gaps and limitations with current sediment bioaccumulation testing, but also understand the advances of sediment bioaccumulation since its initial use in the early 1980s.