Uptake and accumulation of di-n-butyl phthalate in six leafy vegetables under hydroponic conditions

Unveiling the absorption, translocation, and metabolism of penthiopyrad in pakchoi under hydroponic and soil-cultivated conditions

The efficient use of pesticides has long been a topic of public concern, necessitating a thorough understanding of their movement in plants. This study investigates the translocation and distribution of penthiopyrad in pakchoi plants cultivated both in hydroponic and soil-cultivated conditions. Results indicate that penthiopyrad predominantly accumulates in the roots, with concentrations of 11.3-53.9 mg/kg following root application, and in the leaves, with concentrations of 2.0-17.1 mg/kg following foliar application. The bioconcentration factor exceeded 1, with values ranging from 1.2 to 23.9 for root application and 6.4 to 164.0 for foliar application, indicating a significant role in the absorption and accumulation processes. The translocation factor data, which were <1, suggest limited the translocations within pakchoi plants. The limitation may be attributed to the hydrophobic properties of penthiopyrad (log Kow = 3.86), as evidenced by its predominant distribution in the subcellular solid fractions of pakchoi tissues, accounting for 93.1% to 99.5% of the total proportion. Six metabolites (753-A-OH, M12, 754-T-DO, M11, PCA, and PAM) were identified in this study as being formed during this process. These findings provide valuable insights into the absorption, translocation, and metabolism of penthiopyrad in pakchoi.

Personal care products in soil-plant and hydroponic systems: Uptake, translocation, and accumulation

Personal care products (PCPs) are organic compounds that are incorporated in several daily life products, such as shampoos, lotions, perfumes, cleaning products, air fresheners, etc. Due to their massive and continuous use and because they are not routinely monitored in the environment, these compounds are considered emerging contaminants. In fact, residues of PCPs are being discharged into the sewage system, reaching wastewater treatment plants (WWTPs), where most of these compounds are not completely degraded, being partially released into the environment via the final effluents and/or accumulating in the sewage sludges. Environmental sustainability is nowadays one of the main pillars of society and the application of circular economy models, promoting the waste valorisation, is increasingly encouraged. Therefore, irrigation with reclaimed wastewater or soil fertilization with sewage sludge/biosolids are interesting solutions. However, these practices raise concerns due to the potential risks associated to the presence of hazardous compounds, including PCPs. When applied to agricultural soils, PCPs present in these matrices can contaminate the soil or be taken up by crops. Crops can therefore become a route of exposure for humans and pose a risk to public health. However, the extent to which PCPs are taken up and bioaccumulated in crops is highly dependent on the physicochemical properties of the compounds, environmental variables, and the plant species. This issue has attracted the attention of scientists in recent years and the number of publications on this topic has rapidly increased, but a systematic review of these studies is lacking. Therefore, the present paper reviews the uptake, accumulation, and translocation of different classes of PCPs (biocides, parabens, synthetic musks, phthalates, UV-filters) following application of sewage sludge or reclaimed water under field and greenhouse conditions, but also in hydroponic systems. The factors influencing the uptake mechanism in plants were also discussed.

Qualitative and quantitative detection of aflatoxins B1 in maize kernels with fluorescence hyperspectral imaging based on the combination method of boosting and stacking

The most widespread, toxic, and harmful toxin is aflatoxins B1 (AFB1). The fluorescence hyperspectral imaging (HSI) system was employed for AFB1 detection in this study. This study developed the under sampling stacking (USS) algorithm for imbalanced data. The results indicated that the USS method combined with ANOVA for featured wavelength achieved the best performance with the accuracy of 0.98 for 20 or 50 μg /kg threshold using endosperm side spectra. As for the quantitative analysis, a specified function was used to compress AFB1 content, and the combination of boosting and stacking was used for regression. The support vector regression (SVR)-Boosting, Adaptive Boosting (AdaBoost), and extremely randomized trees (Extra-Trees)-Boosting were used as the base learner, while the K nearest neighbors (KNN) algorithm was used as the meta learner could obtain the best results, with the correlation coefficient of prediction (R_p) was 0.86. These results provided the basis for developing AFB1 detection and estimation technologies.

LDPE and biodegradable PLA-PBAT plastics differentially affect plant-soil nitrogen partitioning and dynamics in a Hordeum vulgare mesocosm

Micro and macroplastics are emerging contaminants in agricultural settings, yet their impact on nitrogen (N) cycling and partitioning in plant-soil-microbial systems is poorly understood. In this mesocosm-scale study, spring barley (Hordeum vulgare L.) was exposed to macro or microplastic produced from low density polyethylene (LDPE) or biodegradable plastic at concentrations equivalent to 1, 10 and 20 years of plastic mulch film use. Partitioning of ¹⁵N-labelled fertiliser into plant biomass, soil and leachate yielded a partial mass balance. Soil N partitioning was probed via compound-specific ¹⁵N-stable isotope analyses of soil microbial protein. Concentration-dependent decreases in plant ¹⁵N uptake occurred with increased leached nitrogen for LDPE microplastic. Assimilation into soil microbial protein was higher for biodegradable plastics, which we associate with early-stage biodegradable plastic degradation. Partitioning of ¹⁵N into inorganic soil N pools was affected by LDPE size, with lower assimilation into the microbial protein pool. While microplastics and macroplastics altered soil N cycling, the limited impacts on plant health indicated the threshold for negative effects was not reached at agriculturally relevant concentrations. This study highlights the difference between conventional and biodegradable plastics, and emphasises that the interplay of micro and macroplastics on soil N cycling must be considered in future studies.

Dissipation, uptake, translocation and accumulation of five phthalic acid esters in sediment-Zizania latifolia system

The dissipation, uptake, translocation and accumulation of phthalic acid esters (PAEs) including diallyl phthalate (DAP), diisobutyl phthalate (DIBP), dibutyl phthalate (DBP), benzyl butyl phthalate (BBP) and di-(2-ethylhexyl) phthalate (DEHP) in sediment-Zizania latifolia system were investigated by gas chromatography-flame ionization detector after a QuEChERS pretreatment method. The dissipation rates of PAEs in sediment were positively correlated with exposure time, and more than 68.12% of PAEs in sediment were decreased after 28 d even when the spiked contents were extremely high. All the five PAEs could be taken up by roots from contaminated sediment and subsequently be transported into stems and leaves. There were significant linear correlations between the sediment content and the content in each tissue. DEHP was most readily transported from sediment to roots and stems, followed by BBP, DBP, DIBP and DAP, whereas the order of transportation from roots to leaves was reversed. During 28 d of exposure, the average concentration of each PAE in stems was the highest, followed by roots, leaves and edible parts. DEHP and BBP were the major contaminants in edible parts but could not pose a risk to human health. The accumulation of PAEs in edible parts was influenced by the species and concentration of PAEs as well as the survival time and harvest time of edible parts. The differences in uptake and translocation behaviors among PAEs in plant tissues were significantly correlated to their physicochemical properties, such as alkyl chain length and octanol/water partition coefficient (logK_ow). The results reveal that Zizania latifolia is not only a kind of safe food, but also a potential plant to remediate contaminated sediment by accumulating and degrading PAEs from the habitats.

Recycling Cigarette Filters as Plant Growing Substrate in Soilless System

Two massive wastes are cigarette butts (CB) and stone wool (SW), both representing a threat to the environment. Although the cellulose acetate filters (CAF) in CB are long-term degradable, SW soilless substrates are not. Here, a soilless substrate for growing ornamental plants was manufactured with CAF and compared to commercial SW substrate. CB treatment consisted of a washing in boiling water with a dramatic reduction of pollutants in CAF. Then, cleaned filters were separated, dried, carded to fibers, and subsequently compacted into plugs. The trace pollutants in recycled CAF substrate did not negatively affect the germination of Spartium junceum L. and Lavandula angustifolia Miller seeds as well as the root development of Salvia officinalis L. and Salvia rosmarinus Schleid. stem cuttings. Plants grown in recycled CAF showed a differential species-dependent change of pigments in comparison with those in SW, without compromising their photosynthesis performance. Overall, the results demonstrated that these plants can be well established and grow in recycled CAF, as comparable to SW substrate. This study highlights a novel and promising solution in CAF recycling by turning this litter into an efficient soilless substrate for growing ornamental plants, thus limiting the use of SW and indirectly decreasing its industrial waste flow.

Tissue distribution of phthalates in celery under different cultivation patterns and associated dietary exposure

To investigate tissue distribution, spatial difference, temperature variation, and potential health risks of PAEs in vegetables, celery was used as a model plant. Celery samples were collected from open fields and greenhouses from two provinces in China over four seasons. Celery tissues were analyzed for 16 PAE compounds by gas chromatography-tandem mass spectrometry. The total content of PAEs was 89.0-1130.3 μg kg^-1 dry weight (dw) in stems and 155.0-2730.8 μg kg^-1 dw in leaves. Concentrations of PAEs in celeries showed notable spatial differences (P < 0.05), and the levels in samples from open fields were lower than those in samples from plastic greenhouses. In celeries from greenhouses, higher PAE concentrations were observed for plants grown at high temperatures than in plants grown at low temperatures. Discrepancies in tissue distribution indicated different uptake pathways of PAE contaminants. Risk assessments to humans found that both carcinogenic risks and non-carcinogenic risks of PAEs via celery consumption were at an acceptable level. Further research should consider other exposure pathways of PAEs and pay special attention to reducing PAE contents in vegetables.

Accumulation and transport patterns of six phthalic acid esters (PAEs) in two leafy vegetables under hydroponic conditions

In this study, we investigated the accumulation and transport patterns of six phthalic acid esters (PAEs) in two leafy vegetables under hydroponic conditions. The tested PAEs included dibutyl phthalate (DBP), diethyl phthalate (DEP), diallyl phthalate (DAP), diisobutyl phthalate (DIBP), dimethyl phthalate (DMP) and benzyl butyl phthalate (BBP), and the tested vegetables included Gaogengbai and Ziyoucai. The results revealed that the six PAEs were taken up by vegetables from the solution, although their accumulation and distribution varied among PAEs. The ability of concentrating PAEs into the roots followed the order of BBP > DBP > DIBP > DAP > DEP > DMP, whereas the ability of concentrating PAEs in plant shoots had the opposite order. By analysing the fractionation of the six PAEs in vegetable roots, DMP had the largest proportion in terms of apoplastic movement, while BBP had the largest proportion in terms of symplastic movement. Correlation analyses revealed that the differences among the accumulation and distribution behaviours of the six PAEs in plant tissues were not only related to their physicochemical parameters, such as alkyl chain length and the octanol/water partition coefficient (logK_ow), but also related to the proportion of apoplastic and symplastic movement in the plant roots. In addition, PAEs were more readily accumulated in the Gaogengbai roots than in the Ziyoucai roots; however, the opposite trend was observed for the shoots.