Heavy metal pollution in soils of development zones has attracted wide attention. In this study, soil heavy metal pollution levels and health risks in 15 selected development zones in Shandong Province were investigated for the first time. Geo-accumulation and potential ecological risk indexes were used to assess pollution levels, and health risk was assessed using the US Environmental Protection Agency model. The soil was contaminated by various heavy metals, among which Hg was dominant. A total of 19% of the monitoring sites showed moderate ecological risk level, and low risk level was observed in general. Pollution control of Hg and Cd in each development zone must be strengthened. Health risk analysis showed that noncarcinogenic and carcinogenic risk levels for adults and children were acceptable or nearly acceptable. Positive matrix factorization model was used to identify three possible sources of heavy metal pollution, namely, industrial sources, atmospheric deposition, and transportation. Some specific measures should be taken to prioritize the control of Hg, As, and Cr for protecting the soil environment and human health, especially vulnerable groups, such as children.

There is a growing trend to implement biosecurity measures in small commercial broiler flocks and trying to replace ineffective antimicrobial with alternative materials to interevent a strategy for the control of Campylobacter bacteria in these farms. This study was designed to determine the prevalence rate of Campylobacter spp. in broiler flocks and their environment. Thereafter, assess the efficiency of chitosan, zinc oxide nanoparticles (ZnO NPs), and chitosan/ZnO NPs composite against Campylobacter strains to adopt a novel control strategy based on the ability to use those nanocomposites. A total of 220 samples were collected from broiler flocks, their environment, and farm attendants that direct contact with birds. All samples were subjected to microbiological investigation for isolation, then molecular identification of bacteria using PCR. ZnO NPs and chitosan/ZnO NPs composite were synthesized then characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier-transform infrared spectrum (FT-IR), and X-ray diffraction (X-RD). The efficiency of testing compounds was examined against 30 strains of Campylobacter coli (C. coli) to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The highest percentages of C. coli were isolated from the manure storage area, and broiler litter followed by flies, and feeders (66.7, 53.3, 40.0, and 33.3%, respectively). Both chitosan/ZnO NPs and ZnO NPs at a concentration of 0.5 μg/mL and 1.5 μg/mL, respectively showed complete efficiency (100%) against C. coli compared with chitosan compound. In conclusion, manure storage area and broiler litter represented the main reservoir of Campylobacter bacterial contaminant followed by flies in broiler poultry farms. Chitosan/ZnO NPs composite can be used in any biosecurity program of poultry farms as an alternative to ineffective antimicrobial agents.

Dissolved sulfide, iron (Fe), and phosphorus (P) in a mudflat (Jiaozhou Bay, China) impacted by shellfish aquaculture were measured in situ by the diffusive gradients in thin films (DGT) technique. A combination of porewater and solid-phase chemistry was used to characterize the interplays of Fe and S, and their control on P mobilization. Below the subsurface layer, two times higher fluxes (FDGT) of dissolved Fe²⁺ from porewater to the DGT device than those of dissolved sulfide indicate that dissimilatory iron reduction (DIR) dominates over sulfate reduction (SR). Spatial coupling of dissolved Fe²⁺ and P points to P release driven mainly by reductive dissolution of Fe. Much higher FDGT values of dissolved Fe²⁺ relative to dissolved P imply that oxidative regeneration of Fe oxides at the sediment–water interfaces (SWIs) of the transitional mudflat serves as an effective “iron curtain” of upward diffusing P. In the mudflat sediments of DIR prevalence, the accumulation of total reduced inorganic sulfur (TRIS) is dampened, which can largely ascribed to enhanced oxidative loss of sulfide and/or limited availability of degradable organic carbon in the dynamic regimes. Low dissolved sulfide concentrations in the sediments leave the majority of reactive Fe unsulfidized and thus abundantly available to buffer newly produced sulfide.

This study intended to help illustrate the Mn accumulation ability of Camellia oleifera and provide it as a novel species for possible use in Mn-contaminated sites. Field surveys have been carried out on Mn accumulation in C. oleifera growing near Mn mining area in Hezhou. Pot growth experiments in soil and sand culture were conducted to investigate Mn tolerance, accumulation, and translocation patterns in C. oleifera. C. oleifera grew well and showed no symptoms of Mn toxicity at a Mn treatment level below 1026 mg kg⁻¹ in soil culture and 15.0 mmol L⁻¹ in sand culture. Mn concentrations in leaves and stems reached a maximum of 9612.8 ± 83.5 and 6134.8 ± 94.0 mg kg⁻¹, respectively, in soil culture and 28,465.8 ± 1276.7 and 15,398.4 ± 1148.6 mg kg⁻¹, respectively, in sand culture. Meanwhile, most of the Mn taken from the substrates was transported to the aboveground tissues in soil and sand culture, e.g., over 92.07% of the total Mn taken up by C. oleifera was translocated to shoots in the 10.0 mmol L⁻¹ treatment. Our findings confirmed that C. oleifera exhibited extraordinary Mn accumulation and toleration abilities, and C. oleifera was a suitable species for phytoremediation of Mn-contaminated sites in Guangxi Province.

The main objective of this study is to estimate the total economic loss due to inefficient use of irrigation water in Tunisia. Several approaches have been used for this purpose. The optimal level of water application for different crops is calculated using the actual crop evapotranspiration which is based on FAO-56 method. The residual imputation and yield comparison methods have been used to estimate the economic value of irrigation water for different irrigated crops in different bioclimatic areas. For the empirical analysis, primary data were obtained from a series of surveys that covered 78% of the total irrigated areas and were collected within the framework of the “Virtual Water and Food Security in Tunisia project” (2013–2015). Secondary data about land distribution of crops in Tunisia were taken from the Ministry of Agriculture (2016). Around 724 farms were randomly sampled considering their bioclimatic area, farm type, and production system. The survey included the main 20 crops produced in Tunisia. Results show that most of farmers are either under or over utilizing irrigation water. The value of total direct economic losses, at the country level, of both types of water inefficiencies, was estimated to around 470 million Tunisian Dinars. Therefore, an improvement of water use efficiency at field level through dissemination of information/knowledge on irrigation scheduling and crop water requirements by extension services to farmers is needed to reduce this huge economic loss, reach higher sustainability in water use and improve food security.

In this study the phytotoxic, cytotoxic, genotoxic and mutagenic effects of two commercial fungicide-active compounds, procymidone (PR) and iprodione (IP), were determined. The parameters evaluated were germination and root growth, mitotic index, chromosomal and nuclear aberrations, and molecular analyses were also performed in the model plant Allium cepa L. The results demonstrated that the active compounds PR and IP were phytotoxic, delaying germination and slowing the development of A. cepa seedlings. Moreover, PR and IP showed cytogenotoxicity towards A. cepa meristematic cells, inducing chromosomal changes and cell death. The mutagenic activity of the active compounds was demonstrated by the detection of DNA changes in simple sequence repeat (SSR) and inter-simple sequence repeat (ISSR) markers in the treated cells compared to the negative control. Together, these results contribute to a better understanding of the damage caused by these substances in living organisms and reveal a promising strategy for prospective studies of the toxic effects of environmental pollutants.

In this study, geopolymers were prepared using metakaolin (MK) raw material under different alkali activator moduli (SiO₂/Na₂O = 0.8, 1.2, 1.6, 2.0 M ratio) in order to analyze their capacity and mechanism for adsorbing cadmium (Cd²⁺) from solution. Instrumental analyses including X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy(XPS), Fourier transform infrared (FTIR), and Brunauer-Emmett-Teller (BET) were performed to examine the mineralogical features of the MK and geopolymers before and after Cd²⁺ adsorption. The effect of initial pH, temperature, contact time, and initial concentration on Cd adsorption performance was studied to obtain the equilibrium isotherm. Kinetic data of the geopolymers fitted the pseudo-second-order kinetic model well. Moreover, the adsorption equilibrium data of Cd²⁺ adsorbed by the geopolymers fitted the Langmuir model better than the Freundlich model. The result shows that chemisorption dominates Cd²⁺ adsorption by geopolymers and that the adsorption capacity differs when prepared using different alkali-activated modulus agents. The geopolymer prepared using an alkali activator modulus of 0.8 M (molar ratio) exhibited the best Cd²⁺ adsorption performance with a maximum adsorption capacity of 70.3 mg g⁻¹. The removal rate of Cd²⁺ by geopolymer still remained above 85% after five round of recycling.

Pesticides are highly hazardous chemicals for the environment and human health and their use in agriculture is constantly increasing. Although 1,1,1-trichloro-2,2-bis(4-chlorophenyl) ethane 4,4′-DDT was banned at developed countries, it is still one of the most dangerous of chemical due to accumulation in the environment. It is known that the toxicity of DDT affects some enzyme systems biochemically. The main motivation of this study is to develop an effective adsorbate for the removal DDT, which was chosen as a model hydrophobic pesticide, out of aqueous systems. For this purpose, the bare diatomite particles were magnetically modified and a hydrophobic ligand attached to enhance its adsorptive and physio-chemical features. Under optimal conditions, a high adsorption capacity, around 120 mg/g with the hydrophobic and magnetic diatomite particles, modification of the diatomite particles reduced average pores diameter whereas surface area and total pore volume increased (around 15-folds). After five consecutive adsorption–desorption cycles, no significant decrease in adsorption capability was observed. The adsorption isotherms (Langmuir, Freundlich, and Flory–Huggins) applied to the data indicated that the adsorption process occurred via monolayer adsorption in an entropy-driven manner. The kinetic data also revealed the quick adsorption process without any diffusion limitations. Graphical Abstract

Increased use of colistin, a last resort drug due to failure of carbapenems, has possibly contributed in development and spread of resistance to colistin among Enterobacteriaceae. The colistin belongs to the family of polymyxins, cationic polypeptides, with broad-spectrum activity against Gram-negative bacteria. In this study, we obtained 253 non-duplicate bacterial isolates from sewage water in Delhi and phenotypically screened for colistin resistance. Of the 47 positive isolates, the colistin resistance gene mcr-1 was detected among 5 isolates. Based on 16S ribosomal RNA–based identification, bacterial isolates were found to be Escherichia coli, Aeromonas veronii, and Aeromonas dhakensis. Extended spectrum β-lactamases (ESBL)–resistant determinants CTX-M and TEM were detected in all five mcr-1 positive isolates. On the basis of literature survey, this is the first report of mcr-1 gene from Aeromonas veronii and Aeromonas dhakensis worldwide. Furthermore, mcr-1 gene has not been reported earlier from sewage water in India. Antibiotic susceptibility test of all five isolates against 9 different classes of drugs revealed multidrug-resistant phenotype with high minimum inhibitory concentration values. In vitro transconjugation studies showed successful transfer of mcr-1 and other ESBL-resistant determinants. The occurrence of colistin resistance phenotype conferred by plasmid-based mcr-1 gene in the environment and an ever-increasing list of bacterial isolates is a cause of concern. A comprehensive survey of different water bodies and epidemiological studies are required to assess the risk of dissemination of resistance determinants.

It is claimed that oxidative stress has a prominent role in the mechanism of toxic effects formed by glyphosate-based herbicide (GBH) in living systems. A strong thiol compound, N-acetylcysteine (NAC), has antioxidative and cytoprotective properties. The objective in this subchronic toxicity study was to identify the prophylactic effect of NAC over histopathological changes and oxidative stress induced by GBH in blood, renal, liver, cardiac, and brain tissues. A sum of 28 male Wistar rats were divided into four equal groups, each containing 7 rats. During the study, group I (control group) was supplied with normal rodent bait and tap water ad libitum. The applied agents were 160 mg/kg NAC to group II, 375 mg/kg as equivalent to 1/10 of lethal dose 50% (LD50) of GBH to group III, and 160 mg/kg of NAC and 375 mg/kg of GBH together once per day as oral gavage to group IV for 8 weeks. While GBH decreased the levels of GSH in blood, liver, kidney, and brain tissues, it considerably increased malondialdehyde levels. On the contrary, these parameters happened to improve in the group supplied with NAC. Besides, it was seen that NAC was observed to improve the histopathologic changes in rat tissues induced by GBH. It was concluded that NAC protects oxidative stress and tissue damage induced by GBH in blood and tissue and this prophylactic effect could be attributed to its antioxidant and free radical sweeper character.