Metal concentrations (As, Cd, Pb, Cr, Ba, Co, Ni, Cu, and Zn) in conventional and organic produce were assessed, specifically, five most-consumed vegetables from the US including potato, lettuce, tomato, carrot and onion. They were from four representative supermarkets in a college town in Florida. All vegetables contained detectable metals, while As, Cd, Pb, Cr, and Ba are toxic metals, Co, Ni, Cu, and Zn are nutrients for humans. The mean concentrations of As, Cd, Pb, Cr and Ba in five vegetables were 7.86, 9.17, 12.1, 44.8 and 410 μg/kg for organic produce, slightly lower than conventional produce at 7.29, 15.3, 17.9, 46.3 and 423 μg/kg. The mean concentrations of Co, Ni, Cu, and Zn in five vegetables were 3.86, 58.5, 632, and 2528 μg/kg for organic produce, comparable to conventional produce at 5.94, 68.2, 577, and 2354 μg/kg. For toxic metals, the order followed tomato < lettuce < onion < carrot < potato, with root vegetables being the highest. All metals in vegetables were lower than the allowable concentrations by FAO/WHO. Health risks associated with vegetable consumption based on daily intake and non-carcinogenic risk based on hazard quotient were lower than allowable limits. For the five most-consumed vegetables in the US, metal contents in conventional produce were slightly greater than organic produce, especially for Cd and Pb.

Cadmium (Cd) is a non-essential trace element that accumulates in agricultural soils through the application of Cd-rich phosphate fertiliser. Vegetables can accumulate Cd to concentrations that sometimes exceed food safety standards. We investigated the potential of low-cost soil amendments to reduce Cd uptake by spinach (Spinacia oleracea L.), lettuce (Lactuca sativa L.) and onion (Allium cepa L.). Batch sorption experiments revealed the relative sorption of Cd by biosolids, charcoal, lignite, sawdust, two types of compost, bentonite and zeolite. Lignite and compost had the greatest ability to sorb Cd and were subsequently selected for pot trials, which elucidated their effect on Cd uptake by onions, spinach and lettuce in two market garden soils with native Cd concentrations of 1.45 mg/kg and 0.47 mg/kg. The addition of 2.5% (dry w/w) municipal compost reduced the Cd concentration in onions, spinach and lettuce by up to 60% in both soils. The addition of lignite gave variable results, which depended on the soil type and rate of addition. This Cd immobilisation was offset by soil acidification caused by the lignite. The results indicate that municipal compost is a low-cost soil conditioner that is effective in reducing plant Cd uptake.

Although ozone is well-documented to reduce crop yields in the densely populated Indo-Gangetic Plain, there is little knowledge of its effects in other parts of south Asia. We surveyed crops close to the city of Peshawar, in north-west Pakistan, for visible injury, linking this to passive measurements of ozone concentrations. Foliar injury was found on potato, onion and cotton when mean monthly ozone concentrations exceeded 45 ppb. The symptoms on onion were reproduced in ozone fumigation experiments, which also showed that daytime ozone concentrations of 60 ppb significantly reduce the growth of a major Pakistani onion variety. Aphid infestation on spinach was also reduced at these elevated ozone concentrations. The ozone concentrations measured in April–May in Peshawar, and used in the fumigation experiment, are comparable to those that have been modelled to occur over many parts of south Asia, where ozone may be a significant threat to sensitive crops.

This manuscript describes the reuse of biowaste for the biosynthesis of silver nanoparticles (AgNPs) and their applications. In particular, we hypothesized that the phytochemicals in the onion peels could act as reductant for silver nanoparticles syntheses. AgNO₃ solution (1 mmol) was added dropwise to an aqueous solution of onion peel extract in 3:7 ratio. The reaction mixture was subjected to heating at 90 °C for about 30 min. During the synthesis of the AgNPs, the change of the colour of solution was observed. The AgNPs solution was centrifuged to obtain the two layers, which consists of clear solution and solid layers at 12000 rpm for 30 min. The precipitate was filtered and was re-dispersed in deionised water (25 mL). The solution was centrifuged again to obtain the purified AgNPs. Subsequently, this solution was freeze dried for 48 h to afford the powdered AgNPs. In this work, the structure of the AgNPs were synthesized in spherical shape, with an average size of 12.5 nm observed in the Transmission electron microscopy (TEM) analysis. For catalytic application, the synthesized AgNPs could be applied as green catalyst to promote Knoevenagel and Hantzsch reactions. In most cases, the desired products were obtained in satisfactory yields. In addition, the AgNPs were found to be recyclable for the subsequent reactions. After five successive runs, the average isolated yields for both transformations were recorded to be 91% (Knoevenagel condensation) and 94% (Hantzsch reaction), which indicated that the existing AgNPs could apply as green catalyst in the field of organic synthesis. Furthermore, the AgNPs also showed satisfactory result in antioxidant activity. The current results indicate that the AgNPs can act as alternative antioxidant agent and green catalyst in mediating organic transformations.

Face au developpement de l'utilisation de produits de desodorisation dits "neutralisants" ou "destructeurs" des odeurs, en pulverisation dans l'atmosphere, a l'emission ou a proximite immediate d'ouvrages responsables d'odeurs, l'INERIS (Institut national de l'environnement industriel et des risques) a procede, pour le compte du ministere de l'Amenagement du Territoire et de l'Environnement et de l'ADEME (Agence de l'environnement et de la maitrise de l'energie), a une etude visant une meilleure connaissance des performances de ces produits. Deux types de produits ont ete testes, en pulverisation ou en lavage sommaire des gaz, dans des conditions reelles d'effluents industriels, et dans des conditions de laboratoire, en determinant les efficacites de traitement olfactometriques (reduction de l'odeur) et physico-chimiques (abattement des composes responsables des odeurs) au moyen d'analyses simultanees. A l'issue de ces essais, on peut conclure que les produits de traitement des odeurs, proposes actuellement sur le marche pour desodoriser l'air vicie dans l'industrie, doivent etre utilises avec une grande prudence. En effet, la plupart des produits de pulverisation peuvent apporter un reel confort olfactif par effet de masquage (remplacement d'une mauvaise odeur par une odeur "agreable"), mais il ne faut pas en attendre, a priori, un abattement significatif des polluants presents dans l'air malodorant

Excessive doses of toxic metals such as cobalt may cause detrimental hazards to exposed organisms. Six groups of onion bulbs were formed to investigate the therapeutic effects of grape seed extract (GSE) against cobalt(II) nitrate (Co(NO₃)₂) exposure in Allium cepa L. root tips. Control group was irrigated with tap water, while the latter groups were exposed to 150 mg/L GSE, 300 mg/L GSE, 5.5 ppm Co(NO₃)₂, 5.5 ppm Co(NO₃)₂ + 150 mg/L GSE and 5.5 ppm Co(NO₃)₂ + 300 mg/L GSE, respectively. Co(NO₃)₂ treatment seriously inhibited the root growth, germination and weight gain of the bulbs. Mitotic index was significantly decreased, whereas the chromosomal aberrations and micronuclei incidence exhibited a remarkable increase. In addition, Co(NO₃)₂ induced a variety of anatomical disorders in onion roots. Lipid peroxidation levels of the cellular membranes were assessed measuring the malondialdehyde content (MDA). MDA amount in Co(NO₃)₂-treated group reached the highest level among all groups. Co(NO₃)₂ treatment enhanced the activity of superoxide dismutase and catalase. The addition of GSE to Co(NO₃)₂ solution substantially suppressed the negative effects of Co(NO₃)₂ in a dose-dependent manner by strengthening the antioxidant defence system and reducing the cytotoxicity. Moreover, there was a significant recovery in growth parameters following the grape seed addition to Co(NO₃)₂. GSE had a remarkable reduction in genotoxicity when treated as a mixture with Co(NO₃)₂. Overall data obtained from this investigation proved that GSE, as a promising functional by-product, had a protective effect on Allium cepa L. against the toxic effects of Co(NO₃)₂.

The scope of this study was to investigate the uptake of chromium and nickel by onions (Allium cepa) and potatoes (Solanum tuberosum) and their impact on plant enzymes catalase (CAT, E.C. 1.11.1.6) and peroxidase (POX, E.C. 1.11.1.7). A greenhouse experiment was conducted, simulating the irrigating conditions existing in the two biggest tuber-producing regions of Greece (Asopos and Messapia). Plants were cultivated for 4 months in six irrigation lines, each one supplied by an aqueous solution, containing levels of Cr(VI) and Ni(II) ranging from 0 μg/L (control) to 1,000 μg/L. Significant statistical correlations were observed between (i) the levels of heavy metals in plants, (ii) the levels of heavy metals in plants and in irrigation water, and (iii) the levels of heavy metals and the enzymatic activities in plants. The existing EU legislation has no legal limits for Ni and Cr in food, and the nutritional implications of this study are discussed.

Insecticides stand out as the most dangerous pesticides, and many of them can cause cytotoxic and genotoxic effects in organisms. For this reason, a systematic review was performed focusing on the effect of insecticides on Allium cepa system by two ways: (1) a scientometric study to identify trends and gaps in the literature on the evaluation of insecticides to guide future research efforts and (2) a meta-analytical approach compiling the information to obtain an overall result about insecticide effect on A. cepa. It was found that there is an increasing production of articles in this research area. The H-index of our data set was 11, with an average of 13.72 citations per item. The leader country in this research area was India, followed by Turkey and Brazil. The best cited research area was “Environmental Sciences” and “Environmental Sciences and Ecology,” followed by “Cell Biology.” The most used keywords were genotoxicity, pesticides, and insecticide. The meta-analytical test showed that the number of micronuclei found in onion cells treated with insecticides is higher than that in untreated ones, and the use of pesticides reduced the mitotic index. In conclusion, it is evident the need for more studies about biotechnology, nanotechnology, and biopesticides to develop safer pesticides.