Our study evaluated 163 individuals, being 74 soybean farmers, occupationally exposed to pesticides, and 89 individuals from Goias municipalities, Central Brazil, with similar conditions to the exposed group, comprising the control group. Of the 74 soybean farmers, 43 exposed directly to pesticides and 31 exposed indirectly. The exposed group consisted of individuals aged 19 to 63 years, 21 women and 53 men, and the control group had ages ranging from 18 to 64 years, being 36 women and 53 men. 18.9% of the exposed group were poisoned by pesticides, and the most common symptoms were headache and gastrointestinal problems. The genotype frequencies of the rs2031920 (T>C) polymorphism in the CYP2E1 gene present significant differences between the exposed and control groups (p = 0.02), showing that 24.3% of the exposed group were heterozygotes against 6.7% in the control group. For the OGG1 gene, two SNPs, rs1052133 (G>C) and rs293795 (T>C), were evaluated and the genotype frequencies were not statistically different between the exposed and control groups. The DNA damage was distinct (p < 0.05) in the three analyzed comet parameters (tail length, Olive tail moment, %DNA) between groups. However, there was no influence of age and alcohol consumption between the groups associated with the polymorphisms in the CYP2E1 and OGG1 genes and DNA damage. We also did not find altered hematological and biochemical parameters in the exposed group. Thus, this pioneering study at Goias State carried out an overview of the health of soybean farmers. We evaluated classic laboratory exams, associated with exposure markers (comet assay) and susceptibility markers (genetic polymorphisms), emphasizing the need to expand the Brazilian health assessment protocol. We found, in soybean farmers, increased DNA damage and a higher number of heterozygotes in CYP2E1 gene, compared with the control group, despite the lack of association with age, educational level, smoking, drinking habits, and genetic polymorphisms.

The biomixture composition and the presence of a grass layer in a biobed bioremediation system can improve the performance of these systems to minimize pesticide point-source contamination. In this study, a novel biomixture composed with organic wastes from vineyards and wine industries (vermicompost of winery wastes and vine shoots) and top soil (W) was elaborated. The impact of three pesticides, commonly used in vineyards, on its microbial activity and on the development of turfgrass was determined in a short-term experiment. Moreover, the dissipation of the assayed pesticides was evaluated to stablish their distribution patterns between the turfgrass and the biomixture. For comparison, the original biomixture composed with top soil, peat, and straw (P) was also studied. After 15 days of pesticide application, the development of the turfgrass in both biomixtures was similar. However, the oxidoreductases (dehydrogenase and ortho-diphenol oxidase) and the hydrolytic (FDA and β-glucosidase) enzyme activities were greater in W-biomixture than in P-biomixture. The dissipation of metalaxyl and imidacloprid recorded in the W-biomixtures was significantly greater than in the P-biomixtures. The pesticide dissipation in W-biomixtures followed the same order of their octanol water partition coefficients. Except for tebuconazole, the lower biological activity in the P-biomixture would explain the limited pesticide dissipation. In the grassed biomixtures, most (> 83%) of the non-dissipated imidacloprid and tebuconazole remained in the biomixtures, while metalaxyl was rapidly translocated to the aerial part of the turfgrass. Our results show the potential capability of the novel biomixture as an alternative to the original one in a biobed.

The objective was to evaluate removal efficacy of agrichemicals from water using a small-scale granular activated carbon (GAC) system. The GAC system consisted of a series of three 1.9- to 4.1-L filter canisters filled with 8 × 30 US mesh (595 to 2380 μm) bituminous coal GAC. In experiment 1, 11 agrichemicals (acephate, bifenthrin, chlorpyrifos, flurprimidol, glyphosate, hydrogen peroxide + peracetic acid, imidacloprid, paclobutrazol, didecyldimethylammonium chloride (DDAC), triclopyr, and uniconazole) used in greenhouse and nursery production were exposed to 0, 12, or 64 s of GAC contact time. Chemical concentrations were prepared at a 1:10 dilution of a recommended label rate for ornamental crops to represent a possible residual concentration found in recaptured irrigation or surface water. In experiment 2, three other chemicals [iron ethylene diamine-N,N′-bis(hydroxy phenyl acetic acid) (iron-EDDHA, a chelated iron fertilizer), soracid blue dye (a fertilizer dye), and sodium hypochlorite (a sanitizing agent)] were also tested with 0, 12, 38, or 64 s of GAC contact time. Agrichemical concentration was reduced with 12 s of GAC contact time compared with the 0 s for all chemicals tested, and in most cases was further increased at 64-s contact time. Chemicals reduced below their minimum detection limits with 64 s GAC included acephate, flurprimidol, paclobutrazol, uniconazole, peracetic acid, DDAC, and chlorine (free and total). Percent reduction for other chemicals with 64 s GAC was 72.2% for bifenthrin, 89% chlorphyrifos, 85.3% imidacloprid, 99% glyphosate, 99.4% triclopyr, 99.3% hydrogen peroxide, 47.6% iron-EDDHA, and 94.6% soracid blue dye. Iron-EDDHA and soracid blue dye could be used as indicator chemicals for onsite monitoring of GAC filter efficacy. Results indicate that GAC filtration can remove a wide range of agrichemical contaminants commonly used in greenhouse and nursery production, although the required contact time in commercial production is expected to be greater than in this research study.

Water treatment residuals (WTRs) are by-products of the coagulation and flocculation phase of the drinking water treatment process that is employed in the vast majority of water treatment plants globally. Production of WTRs are liable to increase as clean drinking water becomes a standard resource. One of the largest disposal routes of these WTRs was via landfill, and the related disposal costs are a key driver behind the operational cost of the water treatment process. WTRs have many physical and chemical properties that lend them to potential positive reuse routes. Therefore, a large quantity of literature has been published on alternative reuse strategies. Existing or suggested alternative disposal routes for WTRs can be considered to fall within several categories: use as a pollutant and excess nutrient absorbent in soils and waters, bulk land application to agricultural soils, use in construction materials, and reuse through elemental recovery or as a wastewater coagulant. The main concerns and limitations restricting current and future beneficial uses of WTRs are discussed within. This includes those limitations linked to issues that have received much research attention such as perceived risks of undesirable phosphorous immobilisation and aluminium toxicity in soils, as well as areas that have received little coverage such as implications for terrestrial ecosystems following land application of WTRs.

Co-contamination with heavy metals and pesticides is a severe environmental problem, but little information is available regarding the simultaneous removal of these pollutants. In this study, we showed that Aspergillus sydowii strain PA F-2 isolated from soil contaminated with heavy metal and pesticides can simultaneously degrade trichlorfon (TCF) and adsorb Cd(II) from mineral salt medium. The maximum removal rates for TCF and Cd(II) were 55.52% and 57.90%, respectively, in the treatment containing 100 mg L⁻¹ TCF and 2 mg L⁻¹ Cd(II). As the initial Cd(II) concentration increased (2, 5, and 10 mg L⁻¹), the PA F-2 biomass, TCF degradation rate, and Cd(II) adsorption efficiency decreased, whereas the Cd(II) adsorption capacity by PA F-2 increased. The addition of exogenous glucose and sucrose significantly increased the PA F-2 biomass as well as the removal of TCF and Cd(II). Moreover, the TCF degradation pathway and Cd(II) adsorption mechanism were investigated by gas chromatography–mass spectrometry, scanning electron microscopy, and Fourier transform infrared spectroscopy. These results suggest that PA F-2 has potential applications in the bioremediation of TCF and Cd(II) co-contamination.

In this work, coal bottom ash, a residue generated in thermoelectric power plant, was employed as an alternative catalyst in photo-Fenton reaction for the degradation of sunset yellow dye from liquid solution under visible irradiation. The residue was characterized by techniques such as XRD, XRF, N₂ adsorption/desorption isotherms, SEM/EDS, and FT-IR. The influence of reaction parameters such as solution pH, catalyst dosage, and H₂O₂ concentration on dye removal was analyzed by a central composite rotatable design 2³. According to the characterization results, the presence of iron in the material was confirmed by analysis of chemical composition by XRF, presenting 5.5 wt% in terms of iron oxide. Through the response surface methodology, it was possible to adjust the polynomial model and determine the optimum region of dye removal. The regression model was predictive and significant, with a coefficient of determination (R²) equivalent to 91%, showing a good fit between the experimental and theoretical values. The optimum region reaching a color removal of 91% has a pH level of 2.7, catalyst dosage of 0.9 g L⁻¹, and H₂O₂ concentration of 10 mmol L⁻¹. Therefore, coal bottom ash, an abundant residue with low cost, showed to be a potential catalyst in a photo-Fenton process for the removal of organic contaminant from liquid solution.

Highly contaminated exposed legacy gold mine tailings from the late 1800s are present in many locations throughout North America and other parts of the world that experienced gold rushes at that time. Those tailing fields can pose risks to human health and the environment. Revegetation of tailing fields can reduce dust generation and other risks associated with these sites. The objective of this study was to investigate if native rapid-growing plants could be successfully germinated in mercury (Hg) and arsenic (As) contaminated legacy mine tailings, both untreated and treated with a low dose of sodium selenite (Na₂SeO₃) to promote growth and decrease bioaccumulation of contaminants. After screening many candidates, four wide-spread North American native plant species were selected, Juncus tenuis, Anaphalis margaritacea, Symphotrichum novi-belgii, and Panicum virgatum for their tolerance, presence near legacy gold mine sites, and ability to germinate rapidly in harsh conditions. Three of these species germinated and grew well in untreated tailings except for S. novi-belgii. The selenite treatment increased biomass, emergence, shoot height, and root length in J. tenuis; emergence in A. margaritacea; and root lengths in P. virgatum. This treatment also decreased shoot [Hg] and [As] in P. virgatum by 36% and 40%. Low-dose selenite treatments hold promise for supporting germination and growth of native plants in Hg- and As-contaminated tailing fields.

Many organochlorine pesticides (OCPs) are considerably high toxic, and have bioaccumulation potential and chronic adverse impact on both wildlife and human. This study focuses on the fate and metabolic degradation, which is the potential to be more efficient, economic, and safe compared to the aforementioned conventional methods. By these positive attributes, the present work then investigates the capability of newly isolated pathogenic yeast Pichia kluyveri FM012 for biodegradation of DDT in aquatic culture. Pichia kluyveri FM012 mycelia were cultured in a mineral liquid medium consisting of the solution of DDT (40 mg/l) with some experimental conditions such as the initial pH of the culture (5–8), agitation speed (0–150 rpm), and various carbon and nitrogen sources. The highest biodegradation of DDT by Pichia kluyveri FM012 was shown in the culture with pH 5 and 150 rpm agitation. Moreover, the use of glucose and yeast offers the best performance for the degradation compared to other carbon and nitrogen sources. The highest enzyme activity during the decolorization process was dioxygenase. Fourier-transform infrared spectroscopy (FTIR), UV-Vis spectrophotometer, and GC-MS profile showed that the transformation of DDT has occurred. The present DDE and DDD as metabolites of DDT were confirmed by GCMS at a retention time of 17.8 and 16.6 min. The outcomes of this study have several important implications for future practice, for instance in providing an alternative biodegradation agent to remove some organochlorine pollutants.

17-α-Ethinyl estradiol (EE2) is a widely used drug that acts in the endocrine system and in the environment; even at low concentrations, it causes extensive damage to organisms. The most relevant factors for understanding the EE2 degradation and transport mechanisms in soil are through sorption studies. This study investigated the sorption capacity of EE2 in soil collected amidst vegetation in the region of Sorocaba, São Paulo state, Brazil. The soil samples were submitted to the evaluation of the physical-chemical parameters to characterization. The zero point of charge test (ZPC) was run using the adapted method of the 11-point model. Kinetic tests were then carried out, varying the removal times of the samples with fixed EE2 concentration, whereas, for the isotherm tests, the concentrations were varied, and the fixed contact time was maintained. The final concentrations of EE2 were quantified by high-performance liquid chromatography. Data treatments were carried out using mathematical modeling tests present in the literature. The soil presented a medium texture, being predominantly sandy, and the chemical parameters were classified as high and medium. Only the pH parameter was classified as low. The ZPC was 5.57, indicating an adsorption favorable to the EE2 that presented an average pH of 5.73. The adsorption kinetics showed that the equilibrium time for EE2 in contact with the soil is 12 h. The adsorption isotherm presented values related as favorable and adjustable to the Sips isotherm model and estimated the maximum adsorption capacity of 154.2 mgEE₂ Kgₛₒᵢₗ⁻¹, showing affinity with EE2.

Cyproconazole is a triazole fungicide used to protect a diverse range of fruits, vegetables, and grain crops. As such, it has the potential to enter aquatic environments and affect non-target organisms. The objective of this study was to assess the acute toxicity of the triazole fungicide cyproconazole to zebrafish embryos by assessing mortality, developmental defects, morphological abnormality, oxidative respiration, and locomotor activity following a 96-h exposure. Zebrafish embryos at 6-h post-fertilization (hpf) were exposed to either a solvent control (0.1% DMSO, v/v), or one dose of 10, 25, 50, 100, 250, and 500 μM cyproconazole for 96 h. Data indicated that cyproconazole exhibited low toxicity to zebrafish embryos, with a 96-h LC₅₀ value of 90.6 μM (~ 26.4 mg/L). Zebrafish embryos/larvae displayed a significant decrease in spontaneous movement, hatching rate, and heartbeats/20 s with 50, 100, and 250 μM cyproconazole exposure. Malformations (i.e., pericardial edema, yolk sac edema, tail deformation, and spine deformation) were also detected in zebrafish exposed to ≥ 50 μM cyproconazole, with significant increases in cumulative deformity rate at 48, 72, and 96 hpf. In addition, a 20–30% decrease in basal and oligomycin-induced ATP respiration was observed after 24-h exposure to 500 μM cyproconazole in embryos. To determine if cyproconazole affected locomotor activity, a dark photokinesis assay was conducted in larvae following 7-day exposure to 1, 10, and 25 μM cyproconazole in two independent trials. Activity in the dark period was decreased for zebrafish exposed to 25 μM cyproconazole in the first trial, and hypoactivity was also observed in zebrafish exposed to 1 μM cyproconazole in a second trial, suggesting that cyproconazole can affect locomotor activity. These data improve understanding of the toxicity of cyproconazole in developing zebrafish and contribute to environmental risk assessments for the triazole fungicides on aquatic organisms. We report that, based on the overall endpoints assessed, cyproconazole exhibits low risk for developing fish embryos, as many effects were observed above environmentally-relevant levels.