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

Effective weed management is essential for maximizing sugarcane productivity, with pre-emergence herbicides representing a fundamental strategy for controlling weed infestations. The study evaluates the efficacy of flumioxazin, alone and combined with other herbicides, for weed control in sugarcane. A greenhouse experiments assessed control of various weed species: Rottboellia cochinchinensis, Urochloa decumbens, Digitaria horizontalis, Merremia aegyptia, Merremia cissoides, and Ipomoea triloba. The completely randomized 9 × 5 factorial design with four replications with nine herbicide treatments and five sowing intervals, applied in pots containing a dystrophic Red Latosol. Evaluations included percentage control at 35 d after application (DAA) and reduction in dry mass. Results showed flumioxazin alone had variable efficacy, with high initial effectiveness but significant decline over time. In contrast, combinations such as flumioxazin + metribuzin and flumioxazin + diclosulam maintained high efficacy (>90%) throughout all periods. Flumioxazin + isoxaflutole was initially effective but diminished after 20 DAA. Combinations with herbicides of similar half-lives, like metribuzin, suggested synergistic effects, while pairings with longer half-life herbicides, like imazapic, complemented flumioxazin's action. Mixtures of flumioxazin with other herbicides effectively reduced weed dry mass, highlighting the advantage of herbicide combinations for sustained and efficient weed management in sugarcane cultivation. This study emphasizes the importance of herbicide combinations in overcoming management challenges and selecting appropriate herbicides for diverse field conditions.

Pesticide dislodgeable foliar residues (DFR) and their dissipation half-time (DT₅₀) after application are important parameters for exposure and risk assessment from intended reentry activities or unintended dermal contact with treated crops. To understand the impact of agronomic factors on residue level a statistical based evaluation was conducted using ten DFR studies, with pyrimethanil applied in Scala^® to strawberries, raspberries, peppers, apples, and grapes, 30 trials in total. Influences on initial DFR (DFR0) and DT₅₀ were investigated by multivariate linear regression analysis. The application rate and the crop itself indicate a potential influence on DFR0 when related to ground area applied which is not notable for three dimensional crops regardless of indoor/outdoor cultivation, when related to leaf wall area (LWA). DFR0 values for pyrimethanil do not depend on the number of applications as the range of DT₅₀ values determined for pyrimethanil is consistently small (0.3-2.3 days). All DT₅₀ are significantly lower than the European default (30 days). The noted difference in DT50 of peppers to strawberries is likely attributable to indoor cultivation. A proposal is made how to refine the exposure assessment of pyrimethanil making use of the available DFR0 and DT₅₀ data for other crop types.

Phenanthrene is classified as a priority environmental pollutant because of its impact on the environment and on human health as a mutagenic and carcinogenic agent. The aim of this study was isolated and identified new bacteria with the capability to degrade phenanthrene from Reynosa, Mexico. Achromobacter insolitus, Bacillus cereus, and Microbacterium thalassium had high tolerant to phenanthrene (250 mg L^-1). Biodegradation experiments in liquid culture evidenced that Bacillus cereus strain Sneb1168 degraded 48.58% of phenanthrene at 500 mg L^-1 after 32 days. Remarkably, in the soil system, B. cereus degraded 72.9% of phenanthrene at 250 mg kg^-1 dw. These results highlight the potential of B. cereus strain Sneb1168 to be used as an agent for the remotion of phenanthrene from contaminated soils.

A method for estimation of residues of spirotetramat, tetraniliprole and their metabolites in tomato was validated using QuEChERs extraction with acetonitrile followed by estimation with liquid chromatography-tandem mass spectrometry with coefficient of determination (R²) ≥ 0.99. The untreated samples of tomato and soil fortified with tetraniliprole, spirotetramat and their metabolites at three levels of 0.01, 0.05 and 0.1 µg g^-1, gave a recovery in the range of 72-91% with relative standard deviation, RSD ≤ 8.0%. Combination product (Tetraniliprole 120 g L^-1 + Spirotetramat 240 g L^-1 SC) was applied thrice at 375 and 469 g a. i. ha^-1 dosages at 7 d interval in tomato, from fruit setting stage. Half-life of total tetraniliprole at lower and higher doses was 5.65 and 7.46 d, while that for spirotetramat in tomato were 2.16 and 2.17 d. The waiting periods calculated were 4.72 and 11.97 d for total tetraniliprole and 1.11 and 1.24 d for spirotetramat in tomato. The risk assessment of the residues revealed that the combination product applied at lower and higher doses in tomato did not pose any risk to humans, even when consumed on the same day of application and hence can be safely recommended for management of pest complex in tomato under Indian conditions.

Yeast fermentate (YF) products possess postbiotic properties, which potentially impact gut microbial activities. This study evaluated the effects of supplementing a commercial YF product (ProBiotein^®, PB) in commercial broiler diets on cecal microbial activity, using metabolomic analysis. Birds were supplied ad libitum a corn-soybean meal basal diet supplemented with either 0.75% sand or diets with 0.00% PB, 0.20% PB; 0.50% PB; 0.75% PB substituted for sand. Untargeted metabolomics were incorporated to evaluate similarities and dissimilarities in the cecal metabolome of broilers fed control with no YF and those fed YF diets. Untargeted metabolomics analyses revealed that the YF product had a greater influence on the cecal metabolome than the control diet. For example, profiles of fatty acid and methionine associated metabolites were different in the 0.5YF group compared with the control group. In addition, significant modulations were detected in pathways of sphingolipid, purine and arachidonic acid metabolism. These results reveal that YF products have significant effects on early broiler cecal microbial metabolism. Further research into the effects of feed amendments at different phases of the production cycle may help the poultry industry design strategies for improving bird performance and address potential food safety issues.

Imidacloprid is the most widely used neonicotinoid insecticide worldwide, but it poses serious risks to non-target soil organisms. This study evaluated the toxicity of the commercial formulation Warrant^® (700 mg a.i. kg^-1) using three bioindicators. Lactuca sativa germination, root, and shoot growth were inhibited at concentrations between 0.1 and 2 mg L^-1. All earthworms (Eisenia andrei) died after exposure to filter paper contaminated with 0.1-2 mg L^-1 of imidacloprid, and soil concentrations of 1-2 mg kg^-1 induced morphological alterations that led to mortality. Sublethal concentrations (0.2-0.8 mg a.i. kg^-1) caused avoidance behavior and histopathological damage to the body wall (0.1-0.8 mg a.i. kg^-1) and intestine (0.4-0.8 mg a.i. kg^-1). Although imidacloprid was not lethal to millipedes (Rhinocricus padbergi), it caused histopathological alterations in the midgut at 0.5-2 mg a.i. kg^-1. The extent of sublethal effects increased with imidacloprid concentration. This study emphasizes the importance of evaluating sublethal concentrations and natural soil assays to assess environmental toxicity. It also shows that soil physicochemical properties may influence imidacloprid bioavailability and, consequently, the magnitude of biological responses, underscoring the need for caution in imidacloprid applications to protect soil ecosystems.

Pesticides frequently occur as mixtures in aquatic ecosystems, yet their combined toxicological impacts remain unclear. This study provides the first comprehensive assessment of the acute toxicity of acetamiprid (ACE; 0, 2.5, 5, 10, 20, 40 mg/L) and dimethoate (DM; 0, 12.5, 25, 50, 100, 150 mg/L), both individually and in combination at varying ratios (0:0, 5:10, 10:20, 15:30, 20:40, 25:50 mg/L), in adult banded gourami (Trichogaster fasciata). The 96-h LC₅₀ values were 17.14 mg/L for ACE and 43.54 mg/L for DM when tested alone, but declined to 5.87 mg/L (ACE) and 9.00 mg/L (DM) under combined exposure, indicating enhanced toxicity. Additive index (AI) analysis revealed synergistic effects (AI > 0.25) within lethal dose ranges, causing 10-50% mortality. Behavioral abnormalities, including hyperactivity and loss of balance, were evident within hours of exposure, suggesting neurotoxic effects. Histopathological analysis revealed severe gonadal alterations (ovarian adhesion, oocyte necrosis, empty lumina, and Sertoli cell damage) along with hepatic lesions characterized by leukocyte infiltration and autolysis. This study highlights the novel synergistic toxicity of a neonicotinoid-organophosphate mixture in a non-model fish species, emphasizing the ecological risks of pesticide mixtures and the need for mechanistic investigations to protect aquatic biodiversity.

Humic substances, formed through the decomposition of plant and animal matter, are prevalent world-wide. These substances primarily consist of humin, humic acid (HA), and fulvic acid (FA). There is existing evidence for antifungal properties of these humic constituents. This study aimed to isolate and determine the humic materials derived from organic materials and vermicompost produced using Perionyx excavatus, and to evaluate their antifungal activity against human fungal pathogens, specifically Candida species. Characterization of the humic and FAs was conducted using various techniques, UV-Vis spectroscopy, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and x-ray diffraction (XRD). The results revealed that HA possesses a honeycomb-like structure with fragments and flakes attached to its surface, along with a lumpy and close-grained physical appearance. SEM and XRD analyses further demonstrated the presence of specific crystalline forms in all humic and FA samples. The absorption peaks observed between 250 and 500 nm were indicative of the significant nature of HA. Additionally, the study identified the presence of hydroxyls, amines, alkyl groups, alcoholic contents, and acidic functional groups. Notably, the growth of Candida species was significantly inhibited by both humic and FAs, suggesting that these natural substances could potentially reduce the reliance on chemical antifungal drugs, which often have adverse side effects. Earthworms play a crucial role in breaking down organic matter to form humic substances, as evidenced in vermicompost, vermicast, and vermiwash. Thus, humic and FAs derived from vermiproducts demonstrate potential as alternative therapies for human fungal pathogens.

Diclosulam is widely used for pre-emergent weed control in soybean crops, but information on its effectiveness against Borreria spp. (Borreria spp., syn. Spermacoce) is limited, especially considering physicochemical attributes of soils. This study evaluated diclosulam efficacy in the pre-emergence control of Borreria spinosa and Borreria verticillata in three soils. Two experiments were conducted using a 9 × 3 + 3 factorial design, with nine diclosulam doses (0.27 to 35 g a.i. ha^-1), with a treatment without herbicide and three different types of soils (Oxisol, Inceptisol, and Sandy Oxisol), with four replications. Injury level (%) was assessed at 21, 35, and 55 days after application (DAA), enabling control calculation rate (C₅₀ and C₉₀) and growth reduction doses (GR₅₀ and GR₉₀) were calculated, representing 50% and 90% of control and reduction shoot dry mass, respectively. Diclosulam effectively controlled Borreria spp. in all soils evaluated. Estimated doses for B. spinosa control, ranged from 6.36 to 23.43 g a.i. ha^-1 (C₉₀) and 0.06 to 4.80 g a.i. ha^-1 (GR₉₀). For B. verticillata, C₉₀ ranged from 0.72 to 30.86 g a.i. ha^-1 and GR₉₀ from 1.06 to 5.30 g a.i. ha^-1. Both species were sensitive to diclosulam, supporting its use for pre-emergence control of Borreria spinosa and Borreria verticillata in soils with different physicochemical attributes.

Agricultural activity can contaminate natural resources, such as soil, surface water and groundwater, depending on the interaction between herbicides and soil physicochemical properties that govern retention and transport within the soil profile. This study evaluates the adsorption, desorption and vertical transport of atrazine in Haplustoll soils under two management systems: continuous soybean monoculture (T1) and intensified rotations with grasses and oilseeds (T2) in southwestern Chaco, Argentina. Results show moderate atrazine retention, dependent on the applied concentration, with no significant differences between treatments. Desorption exhibited positive hysteresis, indicating slow herbicide release in successive stages. However, preferential flow through macropores dominated atrazine transport in both systems, evidencing low retention in the soil profile, with high recovery in leachates. Atrazine displayed a high leaching potential in both systems, particularly in soils with low organic carbon content.