The aims of this study were to determine type and application rate of composted animal manure to optimize sweet potato yield relative to N₂O emissions from upland soils. To this end, the study was conducted on upland soils amended with different types and rates of composted animal manure and located at two geographically different regions of South Korea. Field trials were established at Miryang and Yesan in South Korea during the sweet potato (Ipomoea batatas) growing season over 2 years: 2017 (Year 1) and 2018 (Year 2). Three composted animal manures (chicken, cow, and pig) were applied at the rates of 0, 10, and 20 Mg ha⁻¹ to upland soils in both locations. In both Years and locations, manure type did not affected significantly cumulative N₂O emissions from soil during the sweet potato growing season or the belowground biomass of sweet potato. However, application rate of animal manures affected significantly the cumulative N₂O emission, nitrogen (N) in soil, and belowground biomass of sweet potato. An increase in cumulative N₂O emission with application rates of animal manures was related to total N and inorganic N concentration in soil. The belowground biomass yield of sweet potato but also the cumulative N₂O emission increased with increasing application rate of composted animal manures up to 7.6 and 16.0 Mg ha⁻¹ in Miryang and Yesan, respectively. To reduce N₂O emission from arable soil while increasing crop yield, composted animal manures should be applied at less than application rate that produce the maximum belowground biomass of sweet potato.

Many environmental chemicals have been found to exert estrogenic effects in cells and experimental animals by activating nuclear receptors such as estrogen receptors and estrogen-related receptors. These compounds include bisphenols, pesticides, polybrominated diphenyl ethers (PBDEs), organophosphate flame retardants, phthalates and metalloestrogens. G protein-coupled estrogen receptor (GPER) exists widely in numerous cells/tissues of human and other vertebrates. A number of studies have demonstrated that GPER plays a vital role in mediating the estrogenic effects of environmental pollutants. Even at very low concentrations, these chemicals may activate GPER pathways, thus affect many aspects of cellular functions including proliferation, metastasis and apoptosis, resulting in cancer progression, cardiovascular disorders, and reproductive dysfunction. This review summarized the environmental occurrence and human exposure levels of these pollutants, and integrated current experimental evidence toward revealing the underlying mechanisms of pollutant-induced cellular dysfunction via GPER. The GPER mediated rapid non-genomic actions play an important role in the process leading to the adverse effects observed in experimental animals and even in human beings.

Elevated toxins in soybeans extensively threaten Asian residents and over one billion vegetarians worldwide. An integrated dataset of toxic trace metal(loid)s especially cadmium (Cd) analysis in soybean grain samples (n = 5217) from 12 countries/regions of origin was compiled for risk analysis. Worldwide grain Cd averaged 0.093 mg kg⁻¹, but mean values varied 16-fold between regions, with South China (0.32 mg kg⁻¹) > Argentina (0.15 mg kg⁻¹) = German (0.13 mg kg⁻¹) > Japan (0.11 mg kg⁻¹) > the United States (0.064 mg kg⁻¹) > Central-North China (0.020–0.60 mg kg⁻¹) ≥ Iran (0.042 mg kg⁻¹) = Brazil (0.023 mg kg⁻¹) = South Korea (0.020 mg kg⁻¹). Regression analysis suggested widespread contamination and acidic soil features significantly contributed the elevated food Cd contamination worldwide. Arsenic (As) and lead (Pb) are also of concern because excessive levels were often observed in grains. Given that soil Cd bioavailability is generally low in alkaline pH ranges, the feasibility of producing safe food from contaminated land was investigated by greenhouse experiments with one low-Cd soybean cultivar grown on 20 contaminated calcareous soils. Equilibrium-based approaches i.e., 0.01 M CaCl₂ and in-situ porewater extractions, and diffusion-based diffusive gradients in thin-films technique were used to determine the plant-available fractions of soil metal(loid)s to explain the bioaccumulation variation. The results suggested that soybean grains bioaccumulated mean 0.76 mg Cd kg⁻¹, ranging from 0.16 to 2.1 mg kg⁻¹, whereas As and Pb bioaccumulation was low. Cadmium accumulation was closely correlated with plant-available Cd fractions especially the 0.01 M CaCl₂-extractable Cd, but negatively correlated with soil pH. Even in the alkaline pH range, a slight decrease of soil pH would increase grain Cd significantly. Study region and those arable lands that have similar soil conditions are not recommended for growing soybean unless novel remediation strategies are developed.

Uranyl carbonate (UC(VI)) is a stable form of uranyl (U(VI)) that widely coexists with amorphous colloidal silica (ACSi) and humic acid (HA) in carbonate-rich U-contaminated areas. In this context, the cotransport behavior and mechanism of UC(VI) with ACSi (100 mg L⁻¹) and HA colloids in saturated porous media were systematically investigated. It was found that the ACSi and strip-shaped HA have a strong adsorption capacity for UC(VI), and their adsorption distribution coefficient (Kd) is 4–5 orders of magnitude higher than that of quartz sand (QS). In the ternary system, UC(VI) was mainly existing in the colloid-associated form at low UC(VI) concentration (4.2 × 10⁻⁶ M). Compared with the individual transport of UC(VI), the presence of ACSi and strip-shaped HA in the binary system promotes the transport of low-concentration UC(VI) (4.2 × 10⁻⁶ M) but shows a hindering effect when UC(VI) = 2.1 × 10⁻⁵ M. When ionic strength (IS) increased from 0 to 100 mM, the individual transport of UC(VI) and ACSi was weakened owing to the masking effect and the compression of the electrical double layer, respectively; this weakening effect is more pronounced in the binary (UC(VI)–ACSi) system. Notably, the transport of UC(VI) and ACSi in the ternary system is independent of the changes in IS due to the surface charge homogeneity strengthening the electrostatic repulsion between HA and QS. The Derjaguin–Landau–Verwey–Overbeek theory and retention profiles reveal the co-deposition mechanism of ACSi and UC(VI) in the column under different hydrochemical conditions. The nonequilibrium two-site model and the mathematical colloidal model successfully described the breakthrough data of UC(VI) and ACSi, respectively. These results are helpful for evaluating the pollution caused by UC(VI) migration in an environment rich in HA and formulating corresponding effective control strategies.

When assessing oil spills in marine environments, focus has often been on describing degradation and removal of hydrocarbons. However, more and more attention is now given to the formation of mineral oil transformation products, and their potential toxicity and persistency in the environment. The aim of this study was to investigate the formation of dissolved acidic degradation products from crude oil in sea water from the Persian Gulf in a lab-experiment. A super-complex mixture of acidic degradation products was formed in the water phase and compound groups of aliphatic acids, monocyclic aromatic acids-, and polycyclic aromatic acids were identified. More specifically, alkylated PAHs were biodegraded to a high number of aromatic, carboxylic acids by hydroxylation of the alkyl side chains. These degradation products are more bioavailable than their parent compounds, and may therefore constitute a new group of contaminants that should be considered in oil spill assessments.

Copper stress is one of the most severe heavy metal stresses in plants. Grapevine has a relatively higher copper tolerance than other fruit crops. However, there are no reports regarding the tolerance mechanisms of the ‘Shine Muscat’ (‘SM’) grape to a low degree of excess copper stress (Low-ECS). Based on the physiological indicators and multi-omics (transcriptome, proteome, metabolome, and microRNAome) data, 8 h (h) after copper treatment was the most severe stress time point. Nonetheless, copper stress was alleviated 64 h after treatment. Cu ion transportation, photosynthesis pathway, antioxidant system, hormone metabolism, and autophagy were the primary response systems in ‘SM’ grapevine under Low-ECS. Numerous genes and proteins, such as HMA5, ABC transporters, PMM, GME, DHAR, MDHAR, ARGs, and ARPs, played essential roles in the ‘SM’ grapevine's response to Low-ECS. This work was carried out to gain insights into the multi-omics responses of ‘SM’ grapevine to Low-ECS. This study provides genetic and agronomic information that will guide better vinery management and breeding copper-resistant grape cultivars.

Species of the genus Microcystis are among the most notorious cyanobacteria in eutrophic lakes worldwide, with ability present adverse effects on many aquatic organisms. In the surface sediments, Microcystis can be ingested by benthic macroinvertebrates such as Chironomus. However, the potential negative effects of Microcystis on Chironomus life history traits remain unclear. In the present study, we investigated the effect of different Microcystis diets on specific behaviors (burrowing activity, locomotion ability) and life history traits of Chironomus pallidivittatus (Diptera, Chironomidae). We also studied the interactive effects of microcystin-producing M. aeruginosa and temperature (15, 20, and 25 °C) stress on chironomid larvae. The results showed that the inhibitory effect on the cumulative emergence and burrowing activity of larvae was more severe when they were fed M. aeruginosa among the three Microcystis diets groups. Locomotion ability (i.e., locomotor distance and velocity) and adult dry weight decreased significantly in the group fed M. aeruginosa. Locomotion was significantly inhibited and mortality increased when the larvae were fed a mixture of M. aeruginosa and M. wesenbergii, which may have been the result of additive or synergistic effect of the toxins. Under the stress of lower temperature, C. pallidivittatus larvae exhibited weaker locomotion and growth ability, and the emerging adults were mostly male. At both the lower and higher temperature conditions, M. aeruginosa cause cumulative emergence decreased, and sex ratio imbalance, which inhibited the reproduction of larvae from the population perspective. The fourth-instar larvae showed better adaption to Microcystis than did the other instars. This study thus highlights the adverse effects of microcystin-producing M. aeruginosa on Chironomus. It also provides a novel perspective on how environmental factors may influence the behavior and life history traits of chironomid larvae, and how they may respond to cyanobacterial blooms and global warming.

Recently, bioaccumulation of dietary organic selenium (Se) in the ovaries and inhibition of reproduction in female aquatic animals have been reported. However, there is limited data on the subtle reproductive impacts of waterborne exposure to inorganic Se in fish. Here, zebrafish embryos (2 h post-fertilization) were exposed to solutions with environmentally relevant levels of Na₂SeO₃ with concentrations of 0 (control), 7.98 ± 0.31, 25.14 ± 0.15, and 79.60 ± 0.81 μg Se/L for 120 d until they reached sexual maturity. Female zebrafish were selected for reproductive toxicity assessment. In the early embryonic stage, whole-mount in situ hybridization of zebrafish embryos showed that waterborne Na₂SeO₃ exposure did not affect the observed location of vasa expression in primordial germ cells at 24, 48, and 72 h post-fertilization. Life-cycle exposure to 25.14 ± 0.15 and 79.60 ± 0.81 μg Se/L Na₂SeO₃ did not change the testosterone and 17β-estradiol contents in female zebrafish at the endpoint of exposure, but significantly reduced the proportion of early vitellogenic oocytes and mature oocytes. Follicle maturity retardation was accompanied by changes in transcriptional levels of the genes related to the hypothalamus-pituitary-gonad-liver (HPGL) axis. Transcriptional levels of cyp19a and lhr in the ovary were down-regulated, while the transcriptional level of fshr in the ovaries was up-regulated. In the 21-day cumulative spawning experiment, Na₂SeO₃ (25.14 ± 0.15 and 79.60 ± 0.81 μg Se/L) caused fewer eggs to be produced. Additionally, the malformation of zebrafish offspring significantly increased in the group exposed to 79.60 ± 0.81 μg Se/L. In conclusion, for the first time, this study shows that life-cycle exposure to environmentally relevant concentrations of waterborne Na₂SeO₃ significantly delays ovarian maturation and reduces the fertility of the female zebrafish.

Associations between polycyclic aromatic hydrocarbons (PAHs) and respiratory diseases have been widely studied, but the effects of PAH on liver toxicity in adolescents are unclear. Here, 3194 adolescents with NHANES data from 2003 to 2016 were selected. PAH exposure was assessed by measuring PAH metabolites in urine. The outcome variables were the levels of alanine aminotransferase (ALT), aspartate amino transferase (AST) and gamma-glutamyl transpeptidase (GGT). The association between PAH exposure and liver function was evaluated by the weighted quantile sum (WQS) and logistic regression, and the associations between PAHs and inflammation and blood lipids were evaluated by linear regression. Covariates were adjusted for age, ethnicity, BMI, physical activity, family income, cotinine, and urinary creatinine. The results showed that for females, mixed PAH exposure was related to an increased ALT level (OR = 2.33, 95% CI 1.15, 4.72), and 2-fluorene contributed the most (38.6%). Urinary 2-fluorene was positively associated with an elevated ALT level (OR = 2.19 95% 1.12, 4.27, p for trend = 0.004). Mechanistically, 2-fluorene can cause a 3.56% increase in the white blood cell count, a 6.99% increase in the triglyceride level, and 1.70% increase in the total cholesterol level. PAHs may have toxic effects, possibly mediated by inflammation and blood lipids, on the adolescent female liver. Additional confirmatory studies are needed.

Partitioning between nitrate reduction pathways, denitrification and dissimilatory nitrate reduction to ammonium (DNRA) determines the fate of nitrate removal and thus it is of great ecological importance. Sulfide (S²⁻) is a potentially important factor that influences the role of denitrification and DNRA. However, information on the impact of microbial mechanisms for S²⁻ on the partitioning of nitrate reduction pathways in freshwater environments is still lacking. This study investigated the effects of long-term (108 d) S²⁻ addition on nitrate reduction pathways and microbial communities in the sediments of two different freshwater lakes. The results show that the increasing S²⁻ addition enhanced the coupling of S²⁻ oxidation with denitrification instead of DNRA. The sulfide-oxidizing denitrifier, Thiobacillus, was significantly enriched in the incubations of both lake samples with S²⁻ addition, which indicates that it may be the key genus driving sulfide-oxidizing denitrification in the lake sediments. During S²⁻ incubation of the Hongze Lake sample, which had lower inherent organic carbon (C) and sulfate (SO₄²⁻), Thiobacillus was more enriched and played a dominant role in the microbial community; while during that of the Nansi Lake sample, which had higher inherent organic C and SO₄²⁻, Thiobacillus was less enriched, but increasing abundances of sulfate reducing bacteria (Desulfomicrobium, Desulfatitalea and Geothermobacter) were observed. Moreover, sulfide-oxidizing denitrifiers and sulfate reducers were enriched in the Nansi Lake control treatment without external S²⁻ input, which suggests that internal sulfate release may promote the cooperation between sulfide-oxidizing denitrifiers and sulfate reducers. This study highlights the importance of sulfide-driven denitrification and the close coupling between the N and S cycles in freshwater environments, which are factors that have often been overlooked.