Journal of Environmental Science and Health Part B-pesticides Food Contaminants and Agricultural Wastes最新文献

The present investigation aims to study adsorption-desorption behavior of glyphosate and tricyclazole in rice straw-compost biomixtures. To enhance pesticide adsorption and performance of the bio-purification system, rice straw-compost (BM) biomixture was mixed with wheat straw biochar (WBC, 1% and 5%), and adsorption of both pesticides in control (BM) and WBCBM(1%) and WBCBM(5%) biomixtures was compared. The kinetics study suggested that the pseudo-second-order model best explained the time-dependent adsorption of both pesticides and intraparticle adsorption was not the rate-determining step. Tricyclazole was more sorbed than glyphosate in all biomixtures which can be attributed to its lower water solubility. The WBC increased the sorption of both pesticides, but the effect varied with the nature of pesticides and biochar content. The adsorption coefficient values in BM, WBCBM(1%), and WBCBM(5%) biomixtures were 26.74, 38.16, and 51.97 (glyphosate) and 38.07, 59.94, and 84.54 (tricyclazole), respectively. The adsorption data was subjected to the Freundlich, the Langmuir, and the Temkin isotherms, and among them, the Freundlich isotherm best explained pesticide adsorption behavior. Desorption results suggested that the adsorption of glyphosate was more irreversible than tricyclazole and depended upon initial pesticide concentration. This study suggested that biochar mixed rice straw-compost biomixtures can be exploited in bio-purification systems for glyphosate and tricyclazole.

Although previous studies have investigated the occurrence of antibiotic resistance genes (ARGs) in aquaculture, few have monitored the concentrations and propagation of ARGs in biological tissues or investigated the key factors influencing their spread in aquaculture. This study investigated the concentration, propagation, and distribution of ARGs and bacterial communities in water sources, pond water, and tilapia tissues, and their key influencing factors, in a typical tilapia farm. ErmF, sul1, and sul2 were the dominant ARGs with high concentrations. The total concentrations of ARGs (TCAs) in tilapia tissues decreased in the following order: stomach > scales > intestine > gills (P < 0.05). Redundancy analysis and multiple linear regression revealed that suspended solids (SS) and chemical oxygen demand (COD) were positively correlated with the dominant ARGs ermF sul2, and the TCAs (P < 0.05); additionally, Chloroflexi and Bacteroidetes in tilapia aquaculture water were positively correlated with the dominant ARGs ermF and sul2, as well as the TCAs (P < 0.05). This study suggests that SS and COD were the key factors driving the distribution and spread of ARGs in tilapia aquaculture water. Additionally, Chloroflexi and Bacteroidetes were the key bacterial flora affecting the propagation of ARGs in tilapia aquaculture systems.

Ethylene oxide (EtO), although banned for use, is still being detected in foodstuffs that have been fumigated to eradicate pests during storage and transport. Residual levels over the European Union's (EU) maximum residue limit (MRL) pose severe health concerns. Recent detection of EtO and its by-product 2-chloroethanol (2-CE) at alarming levels have led to product recalls throughout the EU. Here, a simple, automated headspace (HS)-trap method for the simultaneous determination of EtO and its derivative 2-CE by gas chromatography-mass spectrometry (GC-MS) at the required MRL of ≤ 0.05 mg/kg has been implemented. Syringe-based HS combined with backflushed trapping technology provided enrichment of multiple extractions from the same sample vial (known as multi-step enrichment or MSE®) to increase sensitivity for EtO and 2-CE analysis by GC-MS using single-ion-monitoring (SIM) mode. Method detection limits (MDLs) of 0.00059 mg/kg and 0.00219 mg/kg for EtO and 2-CE, respectively, were obtained without the need for manual handling, solvent extraction or derivatization methods. Recoveries were shown to average (n = 5) at 98% and 107% for EtO and 2-CE, respectively, and the reproducibility was <10% for both compounds.

Accelerating safety assessments for novel agrochemicals is imperative, advocating for in vitro setups to present pesticide biodegradation by soil microbiota before field studies. This approach enables metabolic profile generation in a controlled laboratory environment eliminating extrinsic factors. In the current study, ten different soil samples were utilized to check their capability to degrade Ametoctradin by their microbiota. Furthermore, five different fungal strains (Aspergillus niger, Aspergillus flavus, Aspergillus fumigatus, Lasiodiplodia theobromae, and Penicillium chrysogenum) were utilized to degrade Ametoctradin in aqueous media. A degradation pathway was established using the metabolic patterns created during the biodegradation of Ametoctradin. In contrast to 47% degradation (T_1/2 of 34 days) when Ametoctradin was left in the soil samples, the fungal strain Aspergillus fumigatus demonstrated 71% degradation of parent Ametoctradin with a half-life (T_1/2) of 16 days. In conclusion, soil rich in microorganisms effectively cleans Ametoctradin-contaminated areas while Fungi have also been shown to be an effective, affordable, and promising way to remove Ametoctradin from the environment.

Given extensive variability in feed composition, the absence of a dedicated DNA extraction kit for poultry feed underscores the need for an optimized extraction technique for reliable downstream sequencing analyses. This study investigates the impact of five DNA extraction techniques: Qiagen QIAamp DNA Stool Mini Kit (Qiagen), modified Qiagen with Lysing Matrix B (MQ), modified Qiagen with celite purification (MQC), polyethylene glycol (PEG), and 1-Day Direct. Genomic DNA amplification and Illumina MiSeq sequencing were conducted. QIIME2-2021.4 facilitated data analysis, revealing significant diversity and compositional differences influenced by extraction methods. Qiagen exhibited lower evenness and richness compared to other methods. 1-Day Direct and PEG enhanced bacterial diversities by employing bead beating and lysozyme. Despite similar taxonomic resolution, the Qiagen kit provides a rapid, consistent method for assessing poultry feed microbiomes. Modified techniques (MQ and MQC) improve DNA purification, reducing bias in commercial poultry feed samples. PEG and 1-Day Direct methods were effective but may require standardization. Overall, this study underscores the importance of optimized extraction techniques in poultry feed analysis, with potential implications for future standardization of effective methods.

The aim of the present study was to assess the selectivity of herbicides applied in the pre and post-planting of pre-sprouted seedlings (PSS). The experiment was conducted in a greenhouse, using a completely randomized design, with nine treatments and four repetitions. The IACSP95-5000 cultivar was used. The treatments consisted of herbicides applied in five doses as follows: in pre-planting: sulfentrazone, diclosulam, imazapic, and imazapyr, in post-planting: ethoxysulfuron, halosulfuron, 2,4-D and MSMA, and a control treatment without herbicide. Injury symptoms were assessed at 7, 15, 30, 45, 60, 75, and 90 days after application (DAA), height, diameter, number of tillers, chlorophyll A, B, and total chlorophyll at 30, 60, and 90 DAA, leaf area, shoot and root dry mass at 90 DAA. The post-emergent herbicides were considered selective. Pre-planting herbicides reduced the variables assessed at 90 DAA, observed by linear regression for diclosulam and imazapic, and exponential regression for imazapyr. Treatments with sulfentrazone caused few injury symptoms, with subsequent recovery. In addition, all the variables analyzed were equal to control, with the sulfentrazone considered selective for the IACSP95-5000 cultivar.

The objective was to evaluate the efficacy of pre-emergence herbicides mixture applied to the soil with and without dead cover crops (Sorghum bicolor) for the control of Amaranthus hybridus L. (smooth pigweed) and its selectivity in soybeans. This study was structured in split plot (2 × 6 + 2), where factor A plots (with and without dead cover) and factor B six herbicides mixture: flumioxazin + S-metolachlor (50.4 + 1,008 g a.i. ha^-1), flumioxazin + imazethapyr (60 + 127.2 g a.i. ha^-1), pyroxasulfone + sulfentrazone (137.6 + 160 g a.i. ha^-1), diuron + sulfentrazone (400 + 200 g a.i. ha^-1), metribuzin + S-metolachlor (326.4 + 1,344 g a.i. ha^-1) and sulfentrazone + imazethapyr (200 + 100 g a.i. ha^-1) and two untreated control plots. As for the results, the herbicides flumioxazin + S-metolachlor, flumioxazin + imazethapyr and pyroxasulfone + sulfentrazone showed excellent control (97-99%) and were not influenced by the plot with and without dead cover. They also showed higher yield soybeans (<2,244 kg ha^-1). All herbicides were selective to the soybeans. Overall, pre-emergence herbicides and cover crops were efficient methods for the control of A. hybridus, which farmers should use to avoid losses in yield soybeans due to weed competition.

Liquid smoke is a food additive and cresols are among its chemical constituents, potentially toxic to human health. Thus, the objective of this study was to develop a method to quantify cresols in liquid smoke. First, the liquid-liquid extraction with low temperature purification (LLE-LTP) was validated for cresols in water, as there are no cresol-free liquid smoke samples. Analyzes were performed by gas chromatography coupled to mass spectrometry in full scan mode. LLE-LTP was subsequently applied in five commercial samples of liquid smoke. Validation results showed that the proposed extraction method was selective for cresols, linear in the range of 0.5 to 35 mg L^-1, limit of quantification of 0.5 mg L^-1, recovery rate between 90% and 104% and relative standard deviation lower than 10%. The quantification of cresols in liquid smoke samples ranged from 3.0 to 38.3 mg L^-1 and the concentration of these chemical contaminants in liquid smoke remained constant for at least 21 days at 25 °C.

Pretilachlor is one of the widely used chloroacetamide herbicides in Asian countries to control weeds in the rice field. The extensive use of herbicides has caused major concern among scientists throughout the world. Therefore, it is essential to develop an efficient method for the remediation of pretilachlor and its harmful by-products from contaminated surfaces. Mycoremediation is known to play a key role in the removal of various environmental contaminants. Hence, in the present study, strain AJN2 Aspergillus ficuum was isolated from a paddy field that was in continuous exposure to pretilachlor for over a decade. The degradation studies showed that the strain was efficiently able to degrade 73% of pretilachlor in an aqueous medium within 15 days of incubation and 70% of its major metabolite PME (2-methyl-6-ethylalanine). The GC/MS profile revealed the formation of aldehyde as the end product of degradation which was confirmed through the infrared fingerprint of the degradation sample. The ligninolytic enzyme activity studies showed that the lignin peroxidase enzyme system could be responsible for the degradation of pretilachlor and its major metabolite. The results highlight that the strain AJN2 A. ficuum could be a potential strain for the bioremediation of pretilachlor from the contaminated areas.

Green tea is one of people's favorite drinks. However, pesticide residues in green tea can cause harm to the human body, and therefore, detection of pesticide residues in green tea is very important. In recent years, the detection of pesticide residues in tea has become a research hotspot. In this paper, a gas chromatography-mass spectrometry/mass spectrometry (GC-MS/MS) detection method of tolfenpyrad pesticide residues in green tea was established by using acetonitrile extractant, dispersive solid-phase extraction purification, temperature programming and application retention time lock with the database. After the sample was extracted with acetonitrile, then the sample was purified by QuEChERS extraction purification tube, afterward isomer B was used as the internal standard for the determination by multiple reaction monitoring mode (MRM) of GC-MS/MS. The results indicated that the experimental data accorded with the criterion on quality control of laboratoris(chemical testing of food), and the requirements of recovery, calibration curve, precision.This method was used to detect tolfenpyrad residues in actual green tea samples in multiple batches, and the satisfactory results were obtained.