Addressing chemical pollution in biodiversity research

Abstract

Chemical pollution can have profound and far-reaching effects on biodiversity and ecosystem health (Bernhardt et al., 2017;Groh et al., 2022;Rillig et al., 2019; Secretariats of the BRS and MC, 2021a, 2021b). Among the five major drivers of biodiversity loss, the greatest pressure is currently exerted by habitat destruction, whereas contributions from other drivers have been estimated to be 3-4 times lower

Chemical Mixtures and Multiple Stressors: Same but Different?

“…Compared with a large part of ecotoxicological research, ecological studies more frequently use field experiments and surveys in ecosystems to establish links between stressors and ecological responses, although laboratory studies are also widely used in multiple stressor research. However, these studies have largely ignored chemicals as stressors except for nutrients (Bernhardt et al, 2017; Groh et al, 2022; Schäfer et al, 2016; Schneeweiss et al, 2023; Sigmund et al, 2023). For example, analyses of general and specific (e.g., freshwater) ecological journals found a comparatively low amount of studies on toxic chemicals, and related United States national project funding was negligible (Bernhardt et al, 2017; Persson et al, 2022; Schäfer et al, 2016).…”

“…For example, analyses of general and specific (e.g., freshwater) ecological journals found a comparatively low amount of studies on toxic chemicals, and related United States national project funding was negligible (Bernhardt et al, 2017; Persson et al, 2022; Schäfer et al, 2016). This is presumably owed to disciplinary division, that is, that toxic chemicals are regarded as the subject matter of a different discipline (Orr et al, 2020) and to the complexity of characterizing mixture exposures and related ecological effects, which requires sophisticated and costly methods of sampling and analyzing chemicals (see below; Sigmund et al, 2023). Moreover, the sheer amount and potential interactions between chemicals have for long complicated the identification of causal relationships and the implementation of eco‐epidemiological approaches aligning applied ecology with ecotoxicology (Bro‐Rasmussen & Løkke, 1984; Posthuma et al, 2020).…”

“…Stressors can be separated into physical (e.g., warming, soil compaction, water flow velocity, fire, land use change), chemical (e.g., water reduction, nutrients, salinity, metals, pesticides), and biological (e.g., invasive species, disease) categories (Rillig et al, 2021), although overlaps exist (e.g., between chemical and physical stressors: microplastics, nanoparticles, and soot particles). Compared with the quantification of most physical and biological stressors and several chemical stressors such as nutrients, salinity, or water level, the labor and financial costs to comprehensively quantify toxicants are much higher (Sigmund et al, 2023). While costly measurement devices and sensors are by no means specific to chemical stressors (e.g., spectrophotometer for nanoparticles, weather stations, sensors for humidity or radiation), the sheer amount of potential chemicals and the fact that many of these are toxic in the smallest traces makes their quantification very costly because complex sample processing steps are often required (e.g., extraction from organisms or soils).…”

To Split or Not to Split: Characterizing Chemical Pollution Impacts in Aquatic Ecosystems with Species Sensitivity Distributions for Specific Taxonomic Groups

“…Characterizing ecotoxicity effects, whether as part of chemical safety assessment, evaluating the environmental performance of products and services in a life cycle perspective, or environmental quality characterization, requires addressing different chemicals’ potential to cause harm on different species, while bridging the disciplines of applied ecology and ecotoxicology . This can be achieved using chemical-specific species sensitivity distributions (SSDs).…”

“…Laboratory-toxicity data-based SSDs are practically used for regulatory purposes and Life Cycle Impact Assessment (LCIA), e.g., to derive protective standards (threshold concentrations) or expected impact levels of ambient chemical pollution. , Recently, their use has expanded to the comprehensive diagnosis of the role of chemical pollution as a driver for biodiversity loss in polluted ecosystems by using SSD-based mixture toxic pressure information (expressed as msPAF, the multisubstance Potentially Affected Fraction of species) as pressure metric, as this resulted in reduced parameters numbers and thus improved statistical power in diagnostic analyses. ,, The choice of required input data and the statistical distribution methods vary among jurisdictions. Models commonly used to fit SSDs include log-normal, log–logistic, or other models that fit the available data well, and commonly, confidence intervals or other metrics of variability and uncertainty are reported. , Crucial to acknowledge is that SSDs are commonly fitted to all available test data per chemicalfollowing the principles developed by the earliest userswhere it is assumed that the SSD describes the exposure-impact relationship for whole field species assemblages.…”