In this study, levels of ten metals (arsenic, cadmium, cobalt, chromium, copper, iron, manganese, nickel, lead, and zinc) in muscles of farmed and escaped farmed rainbow trout (Oncorhynchus mykiss) in the Keban Dam Reservoir (Turkey) were determined. Also, human health risks associated with their consumption were assessed. Of ten metals, only Co and Fe levels in escaped rainbow trout were significantly higher than those in farmed rainbow trout. The metal levels in farmed and escaped rainbow trout were below the maximum permissible limits. The estimated daily intake (EDI) of each metal in both farmed and escaped farmed rainbow trout was much lower than the respective tolerable daily intake (TDI). The target hazard quotient (THQ) values for individual metal and the total THQ values for combined metals were lower than 1 in both farmed and escaped rainbow trout, indicating no health risk for humans. The cancer risk (CR) values estimated for inorganic As in both farmed and escaped rainbow trout indicated low carcinogenic risk to the consumers. According to the maximum allowable monthly consumption limits (CRₘₘ₎, adults may safely consume 24 meals of farmed rainbow trout per month or 39 meals of escaped rainbow trout per month, with minimal adverse carcinogenic and non-carcinogenic health effects. This study revealed that the risk from consuming farmed and escaped farmed rainbow trout in the Keban Dam Reservoir due to these trace elements is minimal.

Tetraethylenepentamine modified sugarcane bagasse was prepared and applied to test its feasibility in removing and recovering Cu²⁺ from wastewater under dynamic condition. Results showed that the Cu²⁺ could be selectively absorbed from wastewater by the modified SCB fixed bed column. To understand the adsorption mechanism, Cd²⁺ had been selected as the model interfering ion to investigate how co-ions influence the adsorption of Cu²⁺ on the sorbent. It was observed that the adsorption capacity of the sorbent for Cu²⁺ (0.26 mmol g⁻¹) was significantly higher than that of Cd²⁺ (0.03 mmol g⁻¹), even when the Cd²⁺ initial concentration was 100 times higher than that of Cu²⁺ in the binary system. This finding indicated that the presence of Cd²⁺ in the solution exerted negligible influence on the adsorption of Cu²⁺ on the modified SCB. The selectivity of the modified sorbent was further confirmed in the Cu/Cd/Mg/Pb/K quinary system. Further analysis to dynamic adsorption experiment illustrated that, due to the presence of amine groups, the modified SCB showed strong coordination ability to Cu²⁺, which allowed the other adsorbed ions (e.g., Cd²⁺) desorbed. This high adsorption selectivity toward Cu²⁺ suggested that this prepared sorbent would be a promising candidate for removing and recovering Cu²⁺ from wastewater.

The use of pesticides in agricultural production originates residues in the environment where they are applied. Pesticide aerial application is a frequent source of exposure to pesticides by persons dedicated to agricultural practices and those living in neighboring communities of sprayed fields. The aim of the study was to assess the genotoxic effects of pesticides in workers occupationally exposed to these chemicals during their aerial application to agricultural fields of Sinaloa, Mexico. The study involved 30 pilots of airplanes used to apply pesticides via aerial application and 30 unexposed controls. Damage was evaluated through the micronucleus assay and by other nuclear abnormalities in epithelial cells of oral mucosa. The highest frequency ratios (FR) equal to 269.5 corresponded to binucleated cells followed by 54.2, corresponding to cells with pyknotic nuclei, 45.2 of cells with chromatin condensation, 3.7 of cells with broken-egg, 3.6 of cells with micronucleus, and 2.0 of karyolytic cells. Age, worked time, smoking, and alcohol consumption did not have significant influence on nuclear abnormalities in the pilots studied. Pesticide exposure was the main factor for nuclear abnormality results and DNA damage. Marked genotoxic damage was developed even in younger pilots with 2 years of short working period, caused by their daily occupational exposure to pesticides.

The applications of multilayered graphenes (MLGs), nanocomposites “MLG–decontaminant” and polydicarbonfluoride intercalation compounds for the localization and deactivation of toxic spills and gaseous emissions under technogenic accidents are investigated in this paper. The intercalation compounds contain oxidizers as intercalants, and MLGs are formed destructively by thermolysis of polydicarbonfluoride intercalation compounds. The sorptive capacity of MLGs (about 240 ml of liquid phase per 1 g of MLG) is much higher than in well-known expanded graphites (EGs) obtained from graphite oxide or graphite acid salts. Our investigation revealed the possibility of the production of the “MLG–decontaminant” nanocomposites with the neutralizator content >95% due to the extremely low (down to 0.4 g/l) apparent density of MLG and its high specific surface (about 370 m²/g). The use of these nanocomposites for the acid–base or redox neutralization of contaminants does not result in the overheating, sputtering or evaporation of liquid phases, because their neutralization products sorb into MLGs. It prevents the soil mineralization by liquid or solid deactivated spills. We revealed that polydicarbonfluoride intercalation compounds with oxidizers (ClF₃, HNO₃, N₂O₄) can be efficiently used for the deactivation of spills and gaseous emissions of nitrogen-containing base compounds.

Knowledge of the dynamics of plant nitrogen (N) uptake at varying irrigation water levels is critical for strategizing increased N recovery efficiency (NRE), water use efficiency (WUE), and maize yield. The N dynamics were studied under various irrigation regimes to evaluate NRE, WUE, and maize yield. A pot experiment was conducted using three irrigation water regimes (50, 75, and 100% field capacity (FC)) and four N fertilizer rates (0, 1.6, 3.2, and 4.8 g pot⁻¹) applied with two fertilizer application methods including foliar and soil applications. The highest plant growth and grain yields were achieved by application of 4.8 g N pot⁻¹ with 100% FC. Contrarily, the maximum WUE (7.0 g L⁻¹) was observed by the lowest irrigation water (50% FC) with the highest N fertilizer rates (4.8 g pot⁻¹). Nitrogen concentration in the stem and grain was linearly increased by increasing N fertilizer rates with irrigation water. However, in the root, N concentration was decreased when the crop was supplied with 100% FC. In plant, maximum N uptake (6.5 mg g⁻¹) was observed when 4.8 g N pot⁻¹ was applied with 100% FC. Nitrogen recovery efficiency was increased by increasing N rate up to 3.2 g pot⁻¹ with 100% FC. Therefore, for achieving maximum WUE and NRE, the highest water and N applications, respectively, are not necessary.

Perchlorate (ClO₄ ⁻) has potential to negatively impact amphibian populations by inhibiting thyroid hormone production, and thus metamorphosis in developing larvae. However, variability exists in species sensitivity, and there is evidence suggesting that natural surface waters can mitigate the anti-metamorphic potential of perchlorate. New Mexico spadefoot toad tadpoles, Spea multiplicata, were exposed to natural surface waters spiked with nominal concentrations of 0, 1000, 1350, 1710, 3000, 5110, and 8000 μg/L perchlorate ion for up to 42 days. No consistent dose-response trends were observed in mortality, rate of metamorphosis, Gosner stage, mass, or length. This study suggests that perchlorate exposure to concentrations as high as 8000 μg/L in natural surface waters does not result in adverse effects on New Mexico spadefoot tadpoles and emphasizes the importance of using site-specific conditions and species when evaluating ecological risks in perchlorate-impacted areas.

Cadmium (Cd) pollution has threatened severely to food safety and human health. A pot experiment and a field experiment were conducted to investigate the difference of Cd accumulation between rice (Oryza sativa L.) lines and F₁ hybrids in Cd-contaminated soils. The adverse effect on biomass of rice lines was greater than that of F₁ hybrids under Cd treatments in the pot experiment. The variations of Cd concentration among rice cultivars in different organs were smaller in stem and leaf, but larger in root and ear. Average proportion of Cd in root of F₁ hybrids was 1.39, 1.39, and 1.16 times higher than those of rice lines at the treatment of 1, 2, and 4 mg Cd kg⁻¹ soil, respectively. Cd concentrations in ear of F₁ hybrids were significantly lower than rice lines with the reduction from 29.24 to 50.59%. Cd concentrations in brown rice of all F₁ hybrids were less than 0.2 mg kg⁻¹ at 1 mg Cd kg⁻¹ soil, in which Lu98A/YaHui2816, 5406A/YaHui2816, and C268A/YaHui2816 could be screened out as cadmium-safe cultivars (CSCs) for being safe even at 2 mg Cd kg⁻¹ soil. C268A/YaHui2816 showed the lowest Cd concentration in root among F₁ hybrids, while Lu98A/YaHui2816 and 5406A/YaHui2816 showed lower capability of Cd translocation from root to shoot under Cd exposure, which eventually caused the lower Cd accumulation in brown rice. The lower level of Cd translocation contributed to reducing the accumulation of Cd in brown rice had been validated by the field experiment. Thus, Lu98A/YaHui2816, 5406A/YaHui2816, and C268A/YaHui2816 could be considered as potential CSCs to cultivate in Cd-contaminated soils (<2 mg Cd kg⁻¹ soil).

Gasoline is a blend of organic compounds used in internal combustion engines. Gasoline-station attendants are exposed to gasoline vapors, which pose a potentially mutagenic risk. According to the International Agency for Research on Cancer, exposure to gasoline and engine exhaust is possibly carcinogenic to humans. We determined the frequency of micronucleus and other nuclear abnormalities, such as pyknotic nuclei, chromatin condensation, cells with nuclear buds, karyolytic cells, karyorrhexis, and binucleated cells in buccal mucosal smears of 60 gasoline-station attendants and 60 unexposed controls. In addition, we explored if factors such as smoking habits, alcohol consumption, and worked years exert an additional synergistic cytotoxic effect. There were statistically significant higher frequencies (p < 0.05) of nuclear abnormalities among exposed attendants compared to the controls. No statistical significant (p > 0.05) additional effect of lifestyle habits such as smoking and alcohol consumption or worked years on the cytotoxicity was observed. The results showed that from the beginning exposure to gasoline vapors increased the frequency of nuclear abnormalities in buccal epithelial cells. Our results provide valuable information on cytotoxic damage for an early pre-symptomatic diagnosis.

To lower phosphorus concentration in Xi’an moat, four different phosphorus-locking materials, namely, calcium nitrate, sponge-iron, fly ash, and silica alumina clay, were selected in this experiment to study their effects on water quality and sediment. Results of the continuous 68-day experiment showed that calcium nitrate was the most effective for controlling phosphorus concentration in overlying and interstitial water, where the efficiency of locking phosphorus was >97 and 90 %, respectively. Meanwhile, the addition of calcium nitrate caused Fe/Al-bound phosphorus (Fe/Al-P) content in sediment declining but Ca-bound phosphorus (Ca-P) and organic phosphorus (OP) content ascending. The phosphorus-locking efficiency of sponge-iron in overlying and interstitial water was >72 and 66 %, respectively. Meanwhile, the total phosphorus (TP), OP, Fe/Al-P, and Ca-P content in sediment increased by 33.8, 7.7, 23.1, and 23.1 %, respectively, implying that under the action of sponge-iron, the locked phosphorus in sediment was mainly inorganic form and the phosphorus-locking efficiency of sponge-iron could be stable and persistent. In addition, the phosphorus-locking efficiency of fly ash was transient and limited, let alone silica alumina clay had almost no capacity for phosphorus-locking efficiency. Therefore, calcium nitrate and sponge-iron were excellent phosphorus-locking agents to repair the seriously polluted water derived from an internal source.

Isolation of diversified bacteria from seawater is a major challenge in the field of environmental microbiology. In the present study, an attempt has been made to select specific membrane with improved property of attaching diversified bacteria. Initially, different concentrations (15, 18, and 20% W/W) of polysulfone (PSF) were used to check their affinity for the attachment of selected gram-positive (Bacillus subtilis) and gram-negative (Escherichia coli) bacteria. Among these, 20% W/W PSF showed maximum attachment. Therefore, membrane prepared with other materials such as polyvinylidene fluoride (PVDF) and polyether sulfone (PES) were used with the same concentration (20% W/W) to check their improved bacterial attachment property. Comparative study of bacterial attachment on three different membranes revealed that PVDF possessed the highest affinity towards both the groups of bacteria. This property was confirmed by different analytical methods viz. contact angle, atomic force microscopy, zeta potential, and flux study and further validated with seawater samples collected from seven sites of western coast and Lakshadweep island of India, using Biolog EcoPlate™. All the samples showed that bacterial richness and diversity was high in PVDF membrane in comparison to surrounding seawater samples. Interestingly, affinity for more diversified bacteria was reported to be higher in water sample with less turbidity and low bacteria load. This finding can facilitate the development of PVDF (20% W/W) membrane as a simple, cheap, and less labor intensive environmental sampling tool for the isolation of diversified bacteria from seawater sample wih different physiochemical properties. Graphical abstract ᅟ