Multispecies bioassay of propylparaben to derive protective concentrations for soil ecosystems using a species sensitivity distribution approach * Dokyung Kim , Lia Kim , Dasom Kim , Shin Woong Kim , Jin Il Kwak , Rongxue Cui , Youn-Joo An * Department of Environmental Health Science, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul, 05029, South Korea article info Article history: Received 23 March 2020 Received in revised form 19 May 2020 Accepted 27 May 2020 Available online 29 May 2020 Keywords: Propylparaben Soil toxicity Ecological risk assessment Species sensitivity distribution Protective concentration abstract Propylparaben is widely used as a preservative in pharmaceuticals and personal care products and is ultimately excreted by the human body. Thus, propylparaben reaches sewage and enters the soil envi- ronment by sludge fertilization and wastewater irrigation. However, there are few existing studies on the toxicity and risks of such chemicals in terrestrial environments. In this study, a multispecies bioassay for propylparaben was performed and protective concentrations (PCs) were derived based on toxicity values by probabilistic ecological risk assessment. Acute and chronic bioassays were conducted on 11 species in eight taxonomic groups (Magnoliopsida, Liliopsida, Clitellata, Entognatha, Entomobryomorpha, Chro- madorea, Chlorophyceae, Trebouxiophyceae). Based on the toxicity values calculated, the PC 95 values for acute and chronic SSDs were 13 and 6 mg/kg dry soil, respectively. Toxicity varied among taxa, with soil algae emerging as the most sensitive to propylparaben. This may be attributable to differences in exposure pathways among species. The exposure pathway of propylparaben can be altered by adsorption to soil particles. As parabens are presently under-regulated globally in terms of their environmental effects, our findings can serve as the basis to propose standard values for environmental protection. © 2020 Elsevier Ltd. All rights reserved. 1. Introduction Parabens, particularly methylparaben and propylparaben, are widely used as preservatives in cosmetics and personal care products, paints, and pharmaceuticals to control microbial growth and prolong shelf life (Madsen et al., 2001). Propylparaben is used as a preservative in food and antifungal agents in 40%e50% of personal care products in the United States (Guo and Kannan, 2013). In the European Union (EU), propylparaben is currently registered for use at 100e1000 tons per annum (European Chemicals Agency, ECHA, b). It is absorbed into the body via dermal and oral exposure routes because it is added in drugs, food, and beverages (Guo, 2017; Lee, 2013; Shirai, 2013; Soni, 2001). Propylparaben is metabolized into propyl-hydroxybenzoic acid, which is rapidly excreted (Bledzka et al., 2014). Thus, propylpar- aben is released into sewage and subsequently removed as an effluent (Haman et al., 2015). However, it can be adsorbed onto sludge during sewage treatment processes and reach the soil environment by sludge fertilization and wastewater irrigation. Propylparaben in the sediment and soil can be detected at con- centrations of up to 64.5 mg/kg in Korea, the United States, and Japan (Liao et al., 2013); 35.2 mg/kg in Spain (Nú~ nez et al., 2008, 2010); and 17.8 mg/kg in China (Yu et al., 2011). Parabens, including propylparaben, are considered relatively safe in cosmetic applications and are regulated separately by jurisdiction (e.g., EU, 2012; 2014; MFDS of Korea, 2016a, 2016b); the US Food and Drug Administration does not set a limit on paraben preservative content (USFDA. GRAS,). However, only a few coun- tries have established environmental regulations on propylparaben to protect the soil ecosystem. In Korea, the United States, and Australia, propylparaben is not subject to any environmental reg- ulations. In the EU, it is listed on the Community Rolling Action Plan, where it is considered a priority for evaluation (ECHA, c). The ECHA has mentioned that “toxicity testing to terrestrial organisms does not need to be conducted as the Chemical Safety Assessment does not indicate a need for further investigations (ECHA, a).” * This paper has been recommended for acceptance by Da Chen. * Corresponding author. E-mail address: anyjoo@konkuk.ac.kr (Y.-J. An). Contents lists available at ScienceDirect Environmental Pollution journal homepage: www.elsevier.com/locate/envpol https://doi.org/10.1016/j.envpol.2020.114891 0269-7491/© 2020 Elsevier Ltd. All rights reserved. Environmental Pollution 265 (2020) 114891