Seasonal variation and ecological risk assessment of Pharmaceuticals and Personal Care Products (PPCPs) in a typical semi-enclosed bay — The Bohai Bay in northern China

The Bohai Bay as a typical semi-enclosed bay in northern China with poor water exchange capacity and significant coastal urbanization, is greatly influenced by land-based inputs and human activities. As a class of pseudo-persistent organic pollutants, the spatial and temporal distribution of Pharmaceuticals and Personal Care Products (PPCPs) is particularly important to the ecological environment, and it will be imperfect to assess the ecological risk of PPCPs for the lack of systematic investigation of their distribution in different season. 14 typical PPCPs were selected to analyze the spatial and temporal distribution in the Bohai Bay by combining online solid-phase extraction (SPE) and HPLC-MS/MS techniques in this study, and their ecological risks to aquatic organisms were assessed by risk quotients (RQs) and concentration addition (CA) model. It was found that PPCPs widely presented in the Bohai Bay with significant differences of spatial and seasonal distribution. The concentrations of ∑PPCPs were higher in autumn than in summer. The distribution of individual pollutants also showed significant seasonal differences. The high values were mainly distributed in estuaries and near-shore outfalls. Mariculture activities in the northern part of the Bohai Bay made a greater contribution to the input of PPCPs. Caffeine, florfenicol, enrofloxacin and norfloxacin were the main pollutants in the Bohai Bay, with detection frequencies exceeding 80 %. The ecological risk of PPCPs to algae was significantly higher than that to invertebrates and fish. CA model indicated that the potential mixture risk of total PPCPs was not negligible, with 34 % and 88 % of stations having mixture risk in summer and autumn, respectively. The temporary stagnation of productive life caused by Covid-19 weakened the input of PPCPs to the Bohai Bay, reducing the cumulative effects of the pollutants. This study was the first full-coverage investigation of PPCPs in the Bohai Bay for different seasons, providing an important basis for the ecological risk assessment and pollution prevention of PPCPs in the bay. © 2022 Elsevier B.V.

Spatiotemporal Distribution and Ecological Risk Assessment of Plastic Additives in Taihu Lake

To reveal the spatiotemporal distribution and risks of plastic additives in Taihu Lake during the COVID-19 pandemic, the occurrences of typical bisphenols, phthalate esters, and benzotriazoles in the surface water of Taihu Lake were investigated. The plastic additives in 19 sites in Taihu Lake were monitored in four seasons, and their potential ecological risks were evaluated. Diethylphthalate (DEP), dimethoxyethyl phthalate (DMEP), benzyl butyl phthalate (BBP), bisphenol A (BPA), and 2-(2H-benzotriazol-2-yl)-4, 6-di-tert-pentylphenol (UV-328) were detected, with detection rates of 100%, 97%, 58%, 98%, and 7%, respectively. During the COVID-19 pandemic, the sharply increasing usage of plastic products did not result in a significant increase in the plastic additives pollution in Taihu Lake. Conversely, the pollution of plastic additives showed a decreasing trend due to reduced human activities. There were significant seasonal differences in the concentrations of plastic additives in Taihu Lake. The average concentrations of plastic additives in spring and summer were 104.7 and 100.3 ng•L-1, respectively, which were higher than those in autumn (30.7 ng•L-1) and winter (29.9 ng•L-1). The plastic additive pollution also showed some differences in spatial distribution. The concentrations of plastic additives near the southwest coast of Taihu Lake were higher than those in other monitoring sites. The presence of plastic additives in Taihu Lake showed low risks to algae with the proportion of 30%. The risks in autumn and winter were higher than those in spring and summer. BPA and UV-328 may have been the main risk factors, which should be of concern. © 2022, Science Press. All right reserved.

Toxicity of 17 Disinfection By-products to Different Trophic Levels of Aquatic Organisms: Ecological Risks and Mechanisms.

Intensified disinfection of wastewater during the COVID-19 pandemic increased the release of toxic disinfection by-products (DBPs). However, studies relating to the ecological impacts of DBPs on the aquatic environment remain insufficient. In this study, we comparatively investigated the toxicities and ecological risks of 17 typical, halogenated DBPs to three trophic levels of organisms in the freshwater ecosystem, including phytoplankton (Scenedesmus sp.), zooplankton (Daphnia magna), and fish (Danio rerio). Toxicity of DBPs was found to be species-specific: Scenedesmus sp. was the most sensitive to haloacetic acids, while D. magna was the most sensitive to haloacetonitriles and trihalomethanes. Specific to each DBP, toxicities were also related to their classes and substituted halogen atoms. Damage to photosystems and oxidative stress served as the potential mechanisms for DBPs toxicity to microalgae. The different sensitivities to DBPs indicate that a battery of bioassays with organisms at different trophic levels is necessary to determine the ecotoxicity of DBPs. Furthermore, the ecological risks of DBPs were assessed by calculating the risk quotients (RQs) based on toxicity data from multiple bioassays. The cumulative RQs of DBPs to all the organisms were greater than 1.0, indicating high ecological risks of DBPs in wastewater effluents.