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

Rigorous risk assessments for those exposed to pesticides are carried out to satisfy crop protection regulatory requirements. Non-dietary risk assessments involve estimating the amount of residue which can be transferred from plant foliage to the skin or clothes, known as dislodgeable foliar residues (DFRs). DFR data are less available than crop residue data as studies are costly and limited by seasonality. European regulatory authorities are reticent to allow extrapolation of study data to different scenarios as the contributory factors have hitherto been poorly identified. This study is the first to use a new laboratory DFR method to investigate how one such factor, pesticide formulation, may affect DFR on a variety of crops. The study used the active substance difenoconazole as both an emulsifiable concentrate (EC 10%) and a wettable powder (WP 10%) with and without adjuvants (Tween 20 and organophosphate tris(2-ethylhexyl)phosphate TEHP) on tomato, French bean and oilseed rape. A comparable DFR% was retained from the WP and EC formulation on most crops except for tomato, where lower DFR% was retained in the case of WP (39 ± 4.7%) compared to EC (60 ± 1.2%). No significant effect of adjuvant addition was observed for either formulation except when mixing TEHP (0.1% w/v) to the EC 10% on French bean, resulting in 8% DFR reduction compared to the EC formulation alone. This research demonstrates the value of a unique DFR laboratory technique in investigating the importance of the formulation and in-tank adjuvants as factors that affect DFR.

The contamination of soil with residual amounts of pesticides remains an urgent challenge for human community. The most efficient approach to address this challenge is the direct microbial degradation of a pesticide in agricultural lands. To this end, the selected microorganisms, which quickly and completely utilize pesticides, are employed. In the present work, two herbicides belonging to different classes of chemical compounds, that is, imazamox and chlorsulfuron were used. The screening of promising microorganisms was carried out among different strains of bacteria and fungi in a liquid mineral medium containing a pesticide as the only source of carbon. It was found that the most active microorganisms were capable of utilizing up to 90% of the active substance for a short time. The dynamics of pesticides degradation indicated that the maximum destruction of the studied substances occurred during the first two weeks of cultivation. Further, the rate of degradation dramatically dropped or stopped at all. An increase in the concentration of pesticides in the cultivation medium almost completely suppressed their degradation. It is interesting that the bacteria were more suitable for the degradation of imazamox, while the fungi rendered the destruction of chlorsulfuron.

The objective of this study was to evaluate the dissipation kinetics of deltamethrin, emamectin benzoate, and hexythiazox in grapes. The QuEChERS method was employed and validated for the precise determination of these three pesticides using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Excellent linearity was observed with regression coefficients exceeding 0.998. Notably, the limits of quantification (LOQ) were significantly lower than the maximum residue limits (MRLs) established for grapes by the European Union. The QuEChERS method l recovered 93.23% of the pesticides with an acceptable RSD of 5.35% (n = 180), demonstrating its suitability for quantifying them in grapes. Half-lives of deltamethrin, emamectin benzoate, and hexythiazox in grapes were 2.62-2.68 days, 8.15-7.30 days, and 3.24-4.01 days, respectively, for both single and double doses. Residues of all pesticides fell below the MRLs by the preharvest interval. This suggests that their application can be considered safe for grapes, ensuring both pest control and consumer safety.

Picoxystrobin is a systemic fungicide widely used on potato, citrus fruit, and Dendrobium officinale. To provide information for the risk assessment of potato, citrus, and Dendrobium officinale, field experiments combined with QuEChERS and HPLC-MS/MS were performed to detect picoxystrobin. Picoxystrobin had good linearity (R² > 0.99), the average recovery rate was 75 - 102%, and the relative standard deviation was 1 - 11%. Picoxystrobin was utilized as the test agent in field experiments, and samples were evaluated and analyzed at various times after the final application utilizing random sampling. The results showed that picoxystrobin residuals in potato and citrus (orange meat) were ˂ 0.01 mg kg^-1, whereas those in citrus whole fruit, D. officinale (fresh), and D. officinale (dried) were < 0.05 - 0.084, 0.16 - 3.82, and 0.34 - 9.05 mg kg^-1, respectively. Based on these results, both the acute risk quotient (2.77%) and chronic risk quotient (8.7%) were ˂100%, and the dietary risk assessment indicated that the intake of picoxystrobin residues in potato, citrus fruit, and D. officinale did not pose a health risk. This study can guide the reasonable use of picoxystrobin in potato, citrus fruit, and D. officinale.

Organochlorine pesticides (OCPs) are persistent pollutants previously used in agriculture, known for their ability to bioaccumulate and pose health risks. This study analyzed samples of roe, viscera, and muscle from Astyanax altiparanae fish collected from the Alagados reservoir in Paraná, Brazil. Samples were prepared through extraction and purification, then analyzed using gas chromatography with an electron capture detector (GC/ECD), chosen for its sensitivity in detecting OCPs. The method was validated for precision, accuracy, and detection limits. Detected OCPs included Aldrin (17.1 to 50.6 ng/g in roe), α-endosulfan (3.4 to 23.5 ng/g), p, p'-DDE (4.2 to 134.7 ng/g), Dieldrin (84.7 to 183.1 ng/g), β-endosulfan (6.0 to 51.6 ng/g), and p, p'-DDT (56.6 to 286.8 ng/g). In viscera, concentrations ranged from Aldrin (19.8 to 93.3 ng/g) to p, p'-DDT (52.3 to 89.2 ng/g). Muscle samples showed similar trends. Principal component analysis indicated a link between higher OCP concentrations and increased abdominal width of the fish. While OCP levels were below FAO and WHO limits, risk quotient calculations suggest potential health risks from consuming these fish.

The adsorption mechanism of S-Metolachlor in an aqueous solution by sawdust biochar derived from Acacia auriculiformis (SAB) was studied. SAB was manufactured at 500 °C for 4 h under oxygen-limited conditions and characterized for SEM, EDS, pHpzc, BET, and FTIR. The adsorption kinetics, isotherm, and diffusion studies of S-Metolachlor and SAB were further explored. Moreover, the effects of the solution pH were examined on the adsorption of S-Metolachlor by SAB. The BET analysis of SAB was achieved at 106.74 m².g^-1 and the solution pH did not significantly influence the S-Metolachlor adsorption. The adsorption data were fitted into a Langmuir isotherm and the PSO model. The film diffusion coefficient D_f (4.93 × 10^-11 to 8.17 × 10^-11 m².s^-1) and the particle diffusion coefficient D_p (1.68 × 10^-11 to 2.65 × 10^-11 m².s^-1) were determined and the rate-limiting step of S-Metolachlor adsorption and SAB was governed by liquid film diffusion. The S-Metolachlor adsorption process onto SAB was controlled by multiple mechanisms, including pore filling, H-bonding, hydrophobic interaction, and π-π EDA interactions. H-bonding is the main interaction for the adsorption of S-Metolachlor and SAB. Conclusively, the study illustrates that biochar produced from Acacia auriculiformis sawdust possessed effective adsorption properties for S-Metolachlor herbicide.

Biopurification system (BPS) or biobeds are low-cost system for decontamination of on-farm generated pesticide waste. A biobed contains a mixture of soil, lignocellulosic biomass and organic matter source (compost/peat) and works on the principal of retention of pesticide in high organic matter matrix and its subsequent degradation by microbes. Bioaugmentation, a green technology, is defined as the improvement of the degradative capacity of biobeds by augmenting specific microorganisms. During last 20 years, several studies have evaluated pesticide degradation in biobeds augmented with bacterial and fungal species and prominent microorganism include genus Pseudomonas, Sphingomonas, Arthrobacter, Phanerochaete, Stereum, Delftia, Trametes, Streptomyces etc. Degradation of pesticides belonging to major classes have been studied in the bioaugmented biobeds. Studies suggested that some pesticides were degraded faster in the bioaugmented biobeds subject to survival and proliferation of degrading microbe. However, no effect of bioaugmentation was observed on degradation of some pesticides and no clear reason for the same was evident. Bioaugmentation with pesticide degrading microorganisms/consortium in combination with rhizosphere-assisted biodegradation could be an optimal strategy for accelerating the degradation of pesticides in biobeds.

This study examined the concentrations of seven heavy metals (Pb, Cu, Zn, Cr, Cd, Ni, and Mn) in the muscle tissue of six commonly consumed fish species (Cyprinus carpio, Labeo rohita, Wallagu attu, Hypophthalmicthys molitrix, Channa punctuate, and Puntius sophore) from the River Indus in the Mianwali district Pakistan. Samples were collected during both pre-monsoon and post-monsoon seasons to assess the potential human health risks associated with these heavy metals. The levels of metals were measured using atomic absorption spectroscopic analysis. The results showed varying concentrations of heavy metals in the fish samples (mg/kg), ranging from 10.17-2.06 for Pb, 41.83-12.54 for Cu, 417.04-41.93 for Zn, 2.06-0.46 for Cr, 0.86-0.08 for Cd, 4.33-1.43 for Ni, and 50.16-8.74 for Mn. Notably, metal concentrations were generally higher during the pre-monsoon season, with Pb consistently exceeding standard limits in the muscle tissue of all fish species. ANOVA analysis revealed significant variations in heavy metal concentrations among different fish species. While the current consumption rate poses no significant health risks, ongoing monitoring of heavy metal concentrations in fish and their environmental sources is crucial to ensure consumer safety and sustainable aquatic ecosystems.

The addition of carbon-rich materials, such as raw feedstocks (RAW) and biochars, to agricultural soils is on the rise. This activity has many advantages, such as improving fertility, increasing water retention, and sequestering carbon. However, they can also increase the sorption of residual herbicides in the soil, reducing the effectiveness of weed control. Thus, the objective of this study was to evaluate soil improvement and the sorption-desorption process of diclosulam in soil unamended and amended with RAW from olive stone and their biochars produced in two pyrolysis temperatures (300 and 500 °C). Oxisol was used in this study, unamended and amended with RAW and biochars (BC300 and BC500) in a rate of 10% (w w^-1). The sorption-desorption process was assessed by batch-equilibrium experiments and the analysis was performed using high-performance liquid chromatography (HPLC). The addition of the three materials to the soil increased the contents of pH, organic carbon, P, K, Ca, Mg, Zn, Fe, Mn, Cu, B, cation exchange capacity, base saturation and decreased H + Al. The unamended soil had K_f (Freundlich sorption coefficient) values of diclosulam sorption and desorption of 1.56 and 12.93 mg^{(1 - 1/n)} L^1/n Kg^-1, respectively. Unamended soil sorbed 30.60% and desorbed 13.40% of herbicide. Soil amended with RAW, BC300, and BC500 sorbed 31.92, 49.88, and 30.93% of diclosulam and desorbed 13.33, 11.67, and 11.16%, respectively. The addition of RAW and biochars from olive stone has the potential to change the soil fertility, but does not interfere with the bioavailability of diclosulam in weed control under field conditions, since the materials slightly influenced or did not alter the sorption-desorption of diclosulam.

Fungicides are specifically used for controlling fungal infections. Strobilurins, a class of fungicides originating from the mushroom Strobilurus tenacellus, act on the fungal mitochondrial respiratory chain, interrupting the ATP cycle and causing oxidative stress. Although strobilurins are little soluble in water, they have been detected in water samples (such as rainwater and drinking water), indoor dust, and sediments, and they can bioaccumulate in aquatic organisms. Strobilurins are usually absorbed orally and are mainly eliminated via the bile/fecal route and urine, but information about their metabolites is lacking. Strobilurins have low mammalian toxicity; however, they exert severe toxic effects on aquatic organisms. Mitochondrial dysfunction and oxidative stress are the main mechanisms related to the genotoxic damage elicited by toxic compounds, such as strobilurins. These mechanisms alter genes and cause other dysfunctions, including hormonal, cardiac, neurological, and immunological impairment. Despite limitations, we have been able to compile literature information about strobilurins. Many studies have dealt with their toxic effects, but further investigations are needed to clarify their cellular and underlying mechanisms, which will help to find ways to minimize the harmful effects of these compounds.