Dissolved organic carbon (DOC) has a major influence upon sorption/desorption and transport of hydrophobic organic contaminants (HOCs) in soil environments. However, the molecular mechanisms of DOC sorption and its effects on aged HOC desorption in contaminated soils still remain largely unclear. Here, effects of three different DOC (one from commercial peat and two from biochars produced at 300 °C and 500 °C pyrolysis temperatures, respectively) and oxalate (as a reference) on abiotic desorption behavior of aged phenanthrene from three agricultural soils were investigated. Results showed that desorption of aged phenanthrene from soils was predominantly dependent on soil organic carbon content. The presence of DOC and oxalate resulted in higher desorption of phenanthrene compared to water alone, and the effects were positively related to soil organic carbon content and DOC/oxalate concentration. The facilitating effects of DOC were further increased during the second consecutive desorption, whereas oxalate had no such effect. Ultra-high-resolution Fourier transform-ion cyclotron resonance-mass spectrometry confirmed the molecular fractionation of DOC at the soil-water interface during DOC sorption. Specifically, the DOC molecules with O-rich moieties were preferentially adsorbed, whereas the molecules with phenolic and aromatic structures were selectively retained in the soil solutions through competitive displacement and co-sorption reactions during sorption. The enriched phenyl structures in the retained DOC facilitated its association with phenanthrene in the solutions and thus the release of phenanthrene from the soils. In contrast, oxalate replaced some organic carbon from the soils and thus released the associated phenanthrene into the solutions. Our findings highlight the importance of the molecular composition and structure of DOC for the desorption of phenanthrene in soil-water environments, which may help improve our understanding of the release and transport of organic compounds in the environments.

Atmospheric deposition, either dry or wet, has been identified as an important pathway of mercury (Hg) input to terrestrial and aquatic systems. Although East Asia is the major atmospheric Hg emission source region, very few studies have been conducted to quantify atmospheric Hg deposition in its downwind region. In this study, 8-year (2009–2016) atmospheric Hg dry deposition was reported at the Lulin Atmospheric Background Station (LABS), a high mountain forest site in central Taiwan. Dry deposition of speciated Hg was estimated using a bi-directional air-surface flux exchange model for gaseous elemental mercury (GEM) and dry deposition models for gaseous oxidized mercury (GOM) and particulate-bound mercury (PBM), making use of the monitored speciated atmospheric Hg concentrations. Annual total Hg dry deposition ranged from 51.9 to 84.9 μg m−2 yr−1 with a multi-year average of 66.1 μg m−2 yr−1. Among the three forms of atmospheric Hg, GEM was the main contributor to the total dry deposition, contributing about 77.8% to the total, due to the high density of forest canopy as well as the much higher concentration of GEM than GOM and PBM at LABS. Mercury dry deposition is higher in winter and spring than in summer and fall, partly due to the elevated Hg concentrations associated with air masses from East and Southeast Asia where with high atmospheric Hg emissions. The mean annual dry/wet deposition ratio of 2.8 at LABS indicated that Hg deposition to forest landscape was governed by dry rather than wet deposition.

Herein, we investigated the effects of di-n-butyl phthalate (DBP) on photosynthesis, ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) content, oxidative damage, and biomass accumulation of different tissues in wheat (Triticum aestivum L) planted in cinnamon soils. The photosynthetic or fluorescence parameters (except for the intercellular carbon dioxide concentration), chlorophyll content, RuBisCO content, and biomass of roots, stems, and leaves decreased at the seedling, jointing, and booting stages under the stress of DBP. Compared with the control, the content of superoxide anions and hydrogen peroxide in the roots, stems, and leaves increased with increasing DBP concentrations at the seedling, jointing, and booting stages. The activities of superoxide dismutase (SOD) and catalase (CAT) in the roots, stems, and leaves increased under the 10 and 20 mg kg−1 DBP treatments; however, no significant changes were observed under the 40 mg kg−1 DBP treatment at the seedling stage (except for the SOD activity in roots). The increase in SOD and CAT activities in the roots, stems, and leaves with increasing DBP concentration at the jointing and booting stages suggested that an increase in the activities of these antioxidant enzymes may play an important role in defending against excess reactive oxygen species under DBP stress. The biomass of wheat roots, stems, and leaves decreased with an increase in DBP concentration, which was presumably caused by a decrease in photosynthesis and RuBisCO. The effect of DBP on wheat roots, stems, and leaves decreased with wheat growth.

Inspired by methods used for life cycle impact assessment (LCIA), we constructed a series of indicators to appreciate the noxiousness of radioactive materials and wastes for human and ecosystem health. According to known potential human health and ecological effects of such materials, six main impact categories were considered to initiate the development of the method: human cancer and non-cancer effects vs. ecotoxicity, considering both chemotoxicity and radiotoxicity. For ecosystems, the noxiousness indicator is based on the concept of Potentially Affected Fraction (PAF), used as a damage indicator at the ecosystem level. The PAF express the toxic pressure on the environment due to one substance. It has been enlarged to mixtures of substances as multi-substances PAF (ms-PAF), and applied to a mix of stable and radioactive substances. Combining ecotoxicity data and a simplified model of exposure of fauna and flora, we proposed a chemotoxicity indicator and a radiotoxicity indicator, ultimately aggregated into a single indicator simply by addition.According to acknowledged practices in LCIA and corresponding available data, we suggested implementing to human health an approach similar to that applied to ecosystems. We produced eigth basic indicators combining effects categories (cancer and non cancer), exposure pathways (ingestion and inhlation) and substances (chemicals and radionuclides). The principle of additivity supporting the whole proposed approach allows their complete aggregation into a single indicator also for human health. Different source terms may be then easily directly compared in terms of human and ecological noxiousness.Applied to the time evolution of a High Level radioactive Waste (HLW), the method confirmed over 1 million years the dominance of the radiotoxicity in the noxiousness of the material for both humans and environment. However there is a change with time in the ranking of the most noxious substances, with stable metals contribution going progressively up. Finally, the HLW global noxiousness, integrating human health and ecological aspects, was assessed through time at three stages and showed a temporal decrease as expected from the dominance of the radiotoxicity.

The quality and availability of water has become a pressing issue worldwide, being particularly important in semi-arid regions, where climate change has aggravated the problem. The use of anthropogenic chemicals, classified as emerging pollutants, adds to the problem representing a treat, since they are not regulated and have a potential impact on human and environmental health. This pressing problem has not been studied widely in complex environments like the one we present here. Distribution and seasonal variability of fecal sterols, alkylphenols, pesticides (emerging pollutants) and nutrients were determined in 35 wells used for agriculture and human consumption in the Valley of Maneadero, located in the semi-arid region of Baja California, Mexico. The presence of the tested pollutants in the saline aquifer was heterogeneous, showing important differences in concentration and distribution. Wells destined for household use showed the highest variability. In these wells, anthropogenic fecal sterols were detected and, alkylphenols, such as octyphenol and nonylphenol had maximum concentrations (2.7 ng/mL). In agriculture and urban wells, we identified DDT and organochlorine pesticides, as well as myclobutanil, which is considered a modern pesticide. Nitrates were identified in concentrations above international standards, mainly during the dry season, in both the agricultural and urban areas. As emerging pollutants represent a negative effect on environmental and human health, this is the first paper showing the importance of measuring this type of pollutant in agricultural/semi-urban areas, especially in aquifers that have been overexploited and communities that have relied on the use of septic tanks for decades.

Tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) has been detected in various environmental media and has been implicated as a weak mutagen or carcinogen, but whether TDCIPP can promote the progression of liver tumor remains unclear. In this study, krasⱽ¹² genetically modified zebrafish, Tg(fabp10:rtTA2s-M2; TRE2:EGFP-krasᴳ¹²ⱽ), a model system in which liver tumors can be induced by doxycycline (DOX), was used to evaluate the liver tumor promotion potential of TDCIPP. Briefly, krasⱽ¹² transgenic females were exposed to 0.3 mg/L TDCIPP, 20 mg/L DOX or a binary mixture of 0.3 mg/L TDCIPP with 20 mg/L DOX, and liver size, histopathology, and transcriptional profiles of liver were determined. Treatment with TDCIPP resulted in increased liver size and caused more aggressive hepatocellular carcinoma (HCC). Compared with the exposure to DOX, TDCIPP in the presence of DOX up-regulated the expression of genes relevant with salmonella infection and the toll-like receptor signaling pathway. These results implied an occurrence of inflammatory reaction, which was sustained by the increase in the amount of infiltrated neutrophils in the liver of Tg(lyz:DsRed2) transgenic zebrafish larvae whose neutrophils were labelled by red fluorescent protein under the lysozyme C promoter. Furthermore, compared with the binary exposure of DOX and TDCIPP, treatment with a ternary mixture of TDCIPP, DOX and inflammatory response inhibitor (ketoprofen) significantly decrease the liver size and the amounts of neutrophils in the livers of kras and lyz double transgenic zebrafish larvae. Collectively, our results suggested that TDCIPP could promote the liver tumor progression by induction of hepatic inflammatory responses.

It has become apparent that the coastal zones of aquatic environments are significantly affected by plastics pollution. The accumulation of marine plastic litter on beaches is an important problem due to their significant environmental impacts. In this study, 13 coastal areas in Iskenderun Bay (NE Levantine coast of Turkey) were sampled in May 2018 to investigate meso and macroplastic (0.5–123.4 cm) pollution. A total of 1424 meso and macroplastic items in five categories (filament, film, foam, fragments, and pellets) were collected. The average meso and macroplastic concentration was 12.2 ± 3.5 pcs m−2 (12.3 ± 3.5 g m−2) and the mean size for all stations was 3.7 ± 0.16 cm. The highest meso and macroplastic concentration was found in the Dörtyol location (46.2 ± 7.6 pcs m−2) and the lowest concentration was found in the Y. Lagün location (2.3 ± 0.2 pcs m−2). Plastics were separated into 14 different groups based on their origins. The most dominant type was hard plastics (broken, fragmented, and deformed) with 59.8% and greenhouse coverage films with 11%. Our results shows that regardless their source plastics fluxes at beaches from various pathways. Results of this study provide useful information for designing monitoring strategies and setting management goals.

Proper management of waste crop residues has been an environmental concern for years. Yellow mealworms (larvae of Tenebrio molitor Linnaeus, 1758) are major insect protein source. In comparison with normal feed wheat bran (WB), we tested five common lignocellulose-rich crop residues as feedstock to rear mealworms, including wheat straw (WS), rice straw (RS), rice bran (RB), rice husk (RH), and corn straw (CS). We then used egested frass for the production of biochar in order to achieve clean production. Except for WS and RH, the crop residues supported mealworms’ life activity and growth with consumption of the residues by 90% or higher and degraded lignin, hemicellulose and cellulose over 32 day period. The sequence of degradability of the feedstocks is RS > RB > CS > WS > RH. Egested frass was converted to biochar which was tested for metal removal including Pb(II), Cd(II), Cu(II), Zn(II), and Cr(VI). Biochar via pyrolysis at 600 °C from RS fed frass (FRSBC) showed the best adsorption performance. The adsorption isotherm fits the Langmuir model, and kinetic analysis fits the Pseudo-Second Order Reaction. The heavy metal adsorption process was well-described using the Intra-Particle Diffusion model. Complexation, cation exchange, precipitation, reduction, deposition, and chelation dominated the adsorption of the metals onto FRSBC. The results indicated that crop residues (WS, RS, RB, and CS) can be utilized as supplementary feedstock along with biochar generated from egested frass to rear mealworms and achieve clean production while generating high-quality bioadsorbent for environment remediation and soil conditioning.

A novel self-assembly method was developed to prepare a γ-Fe₂O₃/graphene oxide (GO) heterogeneous catalyst that showed excellent synergy between photocatalysis and Fenton-like reactions. The γ-Fe₂O₃/GO catalyst prepared on the iron plates demonstrated efficient and reproducible catalytic activities for water treatment. It takes only 80 min to degrade 50 mg L⁻¹ methylene (MB) completely, which is the main non-biodegradable dye in wastewater from the textile industry. The heterogeneous catalyst is stable over a wide range of pH (from 2.0 to 10.2) for MB degradation, and can be easily extracted from solution and repeatedly used with little loss of catalytic activity. The high activity and stability of the catalyst system can be attributed to charge separation between γ-Fe₂O₃ and GO, which could accelerate Fenton-like process and photocatalysis. In addition, the dominant reactive oxidant species responsible for the MB degradation, including the hydroxyl radicals (•OH) and holes (h⁺), were trapped on the surface of the γ-Fe₂O₃/GO composite, as proved by a free-radical quenching experiment. The γ-Fe₂O₃/GO heterogeneous catalyst could potentially provide a solution for removal of non-biodegradable dyes from wastewater in the textile industry.

Bisphenols (BPs) are common environmental pollutants that are ubiquitous in the natural environment and can affect human health. In this study, we explored the effects of perinatal exposure to BPA, BPF and BPAF on liver function involving in oxidative damage and metabolic disorders in male mouse offspring. We found that BPA exposure impairs the antioxidant defense system, increases lipid peroxidation, and causes oxidative damage in the liver. Furthermore, the levels of 13 metabolites were significantly altered following BPA exposure. We found that BPF exposure significantly increased the expression and activity of CAT, suggesting disturbances in the antioxidant defense system. Moreover, BPF exposure led to metabolic disorders in the liver due to changes in the levels of 8 key metabolites. Exposure to BPAF caused no negative effects on oxidative damage, but altered the levels of β-glucose and glycogen. In summary, perinatal exposure to BPA, BPF and BPAF differentially influence oxidative damage and metabolic disorders in the livers of male mouse offspring. The impact of early life exposure to BPs now warrants future investigations.