Urban parks are an important part of the urban ecological environment. The environmental quality of parks is related to human health. To evaluate sources of polycyclic aromatic hydrocarbons (PAHs) in soils of urban parks and their possible health risks, soil samples from 122 parks in Beijing, China, were collected and analyzed. The total content of 16 PAHs between 0.066 and 6.867 mg/kg. Four-ring PAHs were predominant, followed by 5-ring PAHs, while the fraction of 2-ring PAHs was the lowest. The dominant PAHs sources were found to be coal combustion and oil fuels such as gasoline and diesel. A conditional inference tree (CIT) was used to identify the key influencing factors for PAHs. Traffic emissions was the most important factor, followed by coal consumption, as well as the history and location of the park. Incremental lifetime cancer risk (ILCR) for urban park soil in Beijing were low under normal conditions. The soil PAHs exposure pathway risk for both children and adults decreased in the following order: ingestion > dermal contact > inhalation. The risk from soil in parks to children’s health is slightly higher than that of adults, although the health risk due to exposure to PAHs was not extraordinary. Ecosystem risk was negligible.

Triclocarban (TCC) is a contaminant of emerging concern widely applied as an antimicrobial in personal care products and introduced into the terrestrial environment through the application of biosolids (i.e., treated sewage sludge) in agriculture. Displaying the potential to bioaccumulate in the food chain and a high half-life in the soil, the presence of this compound in the environment may lead to potential ecological risks. In this context, TCC toxicity assessments in Eisenia andrei earthworms were carried out through acute, avoidance and chronic tests following cytotoxicity, antioxidant system, i.e. acatalase (CAT), glutathione-S-transferase (GST), glutathione (GSH), lipid peroxidation (LPO), and DNA damage (comet assay) evaluations. An LC₅₀ of 3.3 ± 1.6 mg cm⁻² in the acute contact test and an EC₅₀ of 1.92 ± 0.31 mg kg⁻¹ in the avoidance test during 72 h and 48 h, respectively, were obtained. The behavioral test indicates earthworm avoidance from 15.0 mg kg⁻¹ of TCC. During chronic soil exposure, a 44% reduction in earthworm cell viability was observed after 14 days of exposure to 10 mg kg⁻¹ TCC, while an increase in the percentage of amoebocyte cells also ocurred. Chronic exposure to TCC led to reduced CAT and GST activities, decreased GSH levels and increased LPO in exposed organisms. DNA damage was observed after 45 days from a 1 mg kg⁻¹ dose of TCC. Therefore, TCC exhibits toxicological potential to Eisenia andrei earthworms, mainly during long-term exposures. This study provides mechanistic earthworm information towards understanding the environmental and human health implications of TCC exposure and draws attention to correct biosolid management.

The emission of polychlorinated dibenzo-p-dioxins and -furans (PCDD/F) from full-scale municipal solid waste incinerators (MSWI) is harmful to human and environmental health. This study analyzes the effect of different units of an air pollution control devices (APCDs), i.e. the semi-dry scrubber, fabric filter (FF), selective catalytic reduction (SCR), and wet scrubber (WS), on the removal characteristics and gas- and solid-phase distributions of PCDD/F in MSWI flue gas. APCDs reduce PCDD/F concentrations from 24.9 ng Nm⁻³ to 0.979 ng Nm⁻³ (2.16 ng I-TEQ Nm⁻³ to 0.0607 ng I-TEQ Nm⁻³), with a total removal efficiency (RE) of 96.1% (97.2% I-TEQ). Specifically, APCDs remove more than 95% of both gas- and solid-phase PCDD/F. The FF coupled with active carbon injection (FF + ACI) substantially reduces both gas- and solid-phase PCDD/F concentrations with an RE of 97.2% (98.7% I-TEQ). Additionally, FF + ACI exhibits a better RE of PCDF (98.9%) than PCDD (94.6%) and leads to PCDD congeners dominating the gas-phase. Both desorption and destruction of PCDD/F occur in the SCR, which favors removal of gas-phase PCDD/F but increases solid-phase PCDD/F. Therefore, SCR only decreases PCDD/F with a low RE of 27.6% (16.9% I-TEQ). However, SCR reduces NOₓ with a high RE of 82.3%, which could inhibit the RE of PCDD/F because of their different reaction mechanisms. WS increases PCDD/F in both the gas and solid-phase by 1.95 times (2.57 times for I-TEQ) due to the memory effect, which typically increases the total mass concentration of PCDD/F and the proportions of lower-chlorinated gas-phase PCDD/F. Migration of gas- and solid-phase PCDD/F are also analyzed according to temperature. The results of this study can contribute to the optimized design of industrial APCDs for controlling PCDD/F emissions from MSWI.

This study combines published datasets with unpublished data on plastic ingestion in several North Sea fish species. The combined dataset of 4389 individuals from 15 species allows the analysis of spatial distribution and temporal variability of plastic uptake in fish. Airborne fibre contamination was observed to be the main contributor to fibres encountered in the samples. The number of fibres in samples was strongly related to the time needed to process a sample, not to the number of individual fishes in the sample. Accurate correction for secondary fibre contamination was not possible, but corrections required would be similar to fibre numbers observed in the samples. Consequently, all fibres were omitted from further analysis. The frequency of occurrence and the average number of plastics in fish is generally low (1.8% and 0.022 pieces per organism respectively), with only cod having a higher prevalence (12.3%). While latitude of catch locations influences plastic uptake in fish, no correlation with the distance to the coast was found. Slightly less plastics were ingested in winter, and a decrease in plastics ingested was observed between 2009 and 2018. These factors should be considered when fish species, catch location and time are discussed as indicators for plastic pollution in the European Marine Strategy Framework Directive. We recommend considering demersal cod and pelagic sprat as two species suitable for monitoring plastic ingestion in biota, both on the seafloor and in the water column.

Most laboratory studies have focused on the effects of nanoplastics instead of plastics at the micrometer scale, which are the major microplastics (MPs) discarded in marine environments. Knowledge on the potential effects of micrometer scale plastics on marine microalgae remains limited. It remains unknown whether the micrometer scale plastics also affect microalgal growth, lipid accumulation and resistance to organic contaminants? In addition, the role of polymer-size on the potential hazardous effects of MPs on microalgae is unknown. In the present study, cell populations of a marine diatom, Phaeodactylum tricornutum, were treated with micrometer scale polyethylene (PEMP, 150 μm) and unplasticized polyvinyl chloride (uPVCMP, 250 μm) powders in the laboratory. Growth was assessed using a hemacytometer and neutral lipid concentrations were evaluated using the Nile Red staining method under short-term (four days) and long-term (nine days) exposure. The effects of combined PEMP and phenanthrene (Phe), and uPVCMP and Phe exposures over four days on growth were investigated. Importance scores and SHapley Additive exPlanations (SHAP) values were calculated to assess the contributions of seven factors in exposure systems to the hazardous effects of MPs on microalgae using a machine-learning prediction based on 165 data sets. Both MP types did not influence algal growth and lipid accumulation but minimized algal inhibition by the action of Phe at four days. In addition, lipid accumulation was induced at nine days. Both importance scores and SHAP values indicated that MP polymer-size was the key factor influencing MP toxicity in microalgae. In conclusion, MPs had adverse effects only in chronic tests and the potential adsorption of MPs could have led to the lower levels of toxicity in a combined MP–Phe exposure system. Compared to nanoplastics, MPs in the hundred-micrometer range do not significantly affect growth and their adsorption would not be influenced by size. Therefore, MP size is the most critical factor that should be considered in future laboratory tests and eco-toxicological risk assessments for microalgae.

Evidence is available about the associations of phthalates or their metabolites with blood lipids, however, the mixture effects of multiple phthalate metabolites on blood lipid traits remain largely unknown. In this pilot study, 106 individuals at three age groups of <18, 18- and ≥60 years were recruited from the residents (n = 1240) who were randomly selected from two communities in Wuhan city, China. The participants completed the questionnaire survey and physical examination as well as provided urine samples in the winter of 2014 and the summer of 2015. We measured urinary levels of nine phthalate metabolites using a high-performance liquid chromatography-tandem mass spectrometry. We estimated the associations of individual phthalate metabolite with blood lipid traits by linear mixed effect (LME) models, and assessed the overall association of the mixture of nine phthalate metabolites with blood lipid traits using Bayesian kernel machine regression (BKMR) models. LME models revealed the negative association of urinary mono-2-ethylhexyl phthalate (MEHP) with total cholesterol (TC) as well as of urinary mono-benzyl phthalate or urinary MEHP with low density lipoprotein cholesterol (LDL-C). BKMR models revealed the negative overall association of the mixture of nine phthalate metabolites with TC or LDL-C, and DEHP metabolites (especially MEHP) had a greater contribution to TC or LDL-C levels than non-DEHP metabolites. The findings indicated the negative overall association of the mixture of nine phthalate metabolites with TC or LDL-C. Among nine phthalate metabolites, MEHP was the most important component for the changes of TC or LDL-C levels, implying that phthalates exposure may disrupt lipid metabolism in the body.

Microplastic exposure in one generation of marine organism is believed to impact future generations; the nature of this impact, however, remains unclear, especially across different life stages. We investigated within-generational, latent, and intergenerational effects of various sizes (1.7, 6.8, 10.4, and 19.0 μm) and concentrations (1, 10, 100, and 1000 beads mL⁻¹) of polystyrene microplastics on the planktonic larval and benthic adult life stages of the intertidal barnacle Amphibalanus amphitrite. We exposed parents to microplastics during different developmental stages and examined the life history traits of their offspring. Microplastics had prominent intergenerational—but no within-generational—effects. Parental exposure to 1.7, 6.8, and 10.4 μm microplastics from the larvae to adults significantly increased offspring larval mortality. 1.7 and 6.8 μm microplastics at 1000 beads mL⁻¹ delayed larval development in offspring. Intergenerational effects were observed when microplastics were exposed to parent larvae, suggesting that parental experiences during sensitive early-life stages can have profound impacts across generations. Adverse intergenerational effects of microplastics might drastically reduce larval recruitment and threaten long-term zooplankton sustainability.

The identification and quantification of pharmaceutical and personal care products (PPCPs) in aquatic ecosystems is critical to further studies and elucidation of their fate as well as the potential threats to aquatic ecology and human health. This study used mass balances to analyse the sources, transformation, and transport of PPCPs in rivers based on the population and consumption habits of residents, the removal level of sewage treatment, the persistence and partitioning mechanisms of PPCPs, hydrological conditions, and other natural factors. Our results suggested that in an urbanized river of Guangzhou City, China, the daily consumption of PPCPs was the main reason for the variety of species and concentrations of PPCPs. Through the determination of PPCPs in the river water samples and a central composite design (CCD) methodology, the dominant elimination mechanisms of caffeine and carbamazepine from river water were photolysis and biodegradation, but that of triclosan was sorption rather than biodegradation. The mass data of 3 PPCPs were estimated and corroborated using the measured data to evaluate the accuracy of the mass balance. Finally, caffeine, carbamazepine and triclosan discharged from the Shijing River into the Pearl River accounted for 97.81%, 99.52%, and 28.00%, respectively, of the total mass of these three compounds in the surface water of Shijing River. The results suggest that photolysis are the main process of natural attenuation for selected PPCPs in surface waters of river systems, and the transfer processes of PPCPs is mainly attributed to riverine advection. In addition, the low concentration of dissolved oxygen inhibited the degradation of PPCPs in the surface water of Shijing River.

Understanding the subsurface transport of perfluorooctanoic acid (PFOA) is of considerable interest for evaluating its potential risks to humans and ecosystems. In this study, packed-column experiments were conducted to examine the influence of surface roughness on PFOA transport in unsaturated glass beads, quartz sand and limestone porous media. Results showed decreasing moisture content significantly increased the air-water interfacial adsorption of PFOA and led to greater retardation in all three types of porous media. Particularly, rougher surface (limestone > quartz sand > glass beads) and smaller grain size (i.e. a larger solid specific surface area, SSSA) significantly enhanced PFOA retardation under unsaturated conditions. These results were further supported by bubble column experiments and SSSA analysis of porous media, which demonstrate that except for the factors affecting PFOA transport in solid-water interface (e.g. surface charge and chemical heterogeneity), the greater retardation of PFOA during transport is attributed to the larger air-water interfacial areas associated with rougher surface and smaller grain size and hence greater interfacial adsorption of PFOA. Our results indicated the importance of surface roughness on the retention and transport of PFOA in the unsaturated zone.