Dietary consumption of contaminated vegetables may contribute to polycyclic aromatic hydrocarbon (PAH) exposure in humans; however, this exposure pathway has not been examined thoroughly. This study aims to characterize the concentrations of PAHs in six types of vegetables grown near industrial facilities in Shanghai, China. We analyzed 16 individual PAHs on the US EPA priority list, and the total concentration in vegetables ranged from 65.7 to 458.0 ng g−1 in the following order: leafy vegetables (romaine lettuce, Chinese cabbage and Shanghai green cabbage) > stem vegetables (lettuce) > seed and pod vegetables (broad bean) > rhizome vegetables (daikon). Vegetable species, wind direction, and local anthropogenic emissions were determinants of PAH concentrations in the edible part of the vegetable. Using isomer ratios and principal component analysis, PAHs in the vegetables were determined to be mainly from coal and wood combustion. The sources of PAHs in the six types of vegetables varied. Daily ingestion of PAHs due to dietary consumption of these vegetables ranged from 0.71 to 14.06 ng d−1 kg−1, with contributions from Chinese cabbage > broad bean > romaine > Shanghai green cabbage > lettuce > daikon. The daily intake doses adjusted by body weight in children were higher than those in teenagers and adults. Moreover, in adults, higher concentrations of PAHs were found in females than in males. For individuals of different age and gender, the incremental lifetime cancer risks (ILCRs) from consuming these six vegetables ranged from 4.47 × 10−7 to 6.39 × 10−5. Most were higher than the acceptable risk level of 1 × 10−6. Our findings demonstrate that planting vegetables near industrial facilities may pose potential cancer risks to those who consume the vegetables.

Phytoremediation coupled with agro-production is considered a sustainable strategy for remediation of trace element contaminated fields without interrupting crop production. In this study hyperaccumulator Sedum alfredii was intercropped with a leguminous plant fava bean (Vicia fava) in cadmium (Cd) and lead (Pb) co-contaminated field to evaluate the effects of intercropping on growth performance and accumulations of trace elements in plants with plant growth promoting endophyte (PGPE) consortium application. The results showed, compared with monoculture, intercropping coupled with inoculation application promoted biomass as well as Cd and Pb concentrations in individual parts of both plants, thus increasing the removal efficiencies of trace elements (4.49-folds for Cd and 5.41-folds for Pb). Meanwhile, this superposition biofortification measure maintained normal yield and nutrient content, and limited the concentration of Cd and Pb within the permissible limit (<0.2 mg kg⁻¹ FW) in fava bean during the grain production. These results demonstrated a feasible technical system for phytoremediation coupled with agro-production in slightly or moderately Cd and Pb co-contaminated field, and also provided useful information for further investigation of interaction mechanisms between intercropping and PGPEs inoculation.

Fluorine (F) is widely distributed in soils and is not an essential element for the normal growth of a plant, but in higher concentrations, it is toxic. However, the environmental toxicity of F in soils is still controversial. A pot experiment of broad bean and maize under the exposure to F was performed to elucidate F phytotoxicity and the response of the microbial community in soils. Six different levels (0, 200, 400, 600, 800, and 1000 mg kg–¹) of sodium fluoride were spiked into the soil. The results revealed that the height of stem and root decreased with increasing concentration of F. Germination rate and fresh weight showed no difference in different treatments. At the treatment of 1000 mg kg⁻¹ F, the degradation rates of pigments were 30.6%, 42.9%, and 35.7% for chlorophyll a, chlorophyll b, and total chlorophylls compared with control, respectively. All treatments showed a higher level of F accumulation in root than that in stem and leaf, and stem had a minimum F accumulation. Proteobacteria was the dominant species in bacteria and the relative abundance of Proteobacteria declined significantly with F exposure. Moreover, the number of microbial species both in bacteria and fungus was reduced for the increase of F. In general, our results revealed that high concentrations of F inhibited the growth of broad bean and maize but without visual symptom. The effect of fluorine on broad bean and maize is clarified in the present study which is instructive for agricultural safety.

This study provides the evidence for oxytetracycline (OTC) uptake by earthworm and horsebean after removing extractable OTC in cinnamon soil using water (T₁), 0.1 mol/L CaCl₂ (T₂), and 0.1 mol/L Na₂EDTA-McIlvaine (T₃), respectively. The control was the soil without removing any extractable OTC. During horsebean exposure, the transformation from non-extractable to extractable fractions in soils depended mainly on the alternation of wetting and drying. Two organisms increased significantly OTC concentrations of McIlvaine-fraction in soils in comparison to the absence of organisms. The removal promoted the accumulation concentration and the bioaccumulation factor (BAF) of OTC in two organisms as the order: T₃ > T₂/T₁ > the control. And the promotion was stronger for horsebean than ones for earthworm. OTC accumulation in earthworm was mainly from the digestion absorption due to limited soil extractable OTC (0–0.976 mg/kg). OTC uptake by horsebean was directly through root uptake; therefore, the removal of soil extractable fractions decreased significantly OTC accumulation in root. However, the removal promoted OTC accumulation in shoot and OTC translocation from root to shoot, especially with the highest transfer factor (TF) in T₃ reaching up to 31.7. Maybe, in T₃, this was caused by the combined effect of root as the effective transport passageway of OTC and less loss of soil extractable OTC released during 28-day exposure. These present results demonstrated the high ecological risk of remained OTC in cinnamon soil after removing all extractable fractions due to its high accumulation in soil organisms and the strong transformation from soil non-extractable to extractable fraction under certain cultivation conditions such as alternation of wetting and drying.

Phytoremediation is an important solution to soil pollution management. The goal of this study is to determine the biosorption ability of the two selected fungi (Aspergillus niger and Penicillium chrysosporium) under heavy metal stress on faba bean plants. The fungal strains produced phytohormones, siderophore, ACC deaminase, and secondary metabolites. The biosorption capacity of A. niger and P. chrysosporium was 0.09 and 0.06 mg g⁻¹ and 0.5 and 0.4 mg g⁻¹ in media containing Cd and Pb, respectively. Fourier transform infrared spectroscopy of the fungal cell wall show primary functional groups like hydroxyl, amide, carboxyl, phosphoryl, sulfhydryl, and nitro. Therefore, A. niger and P. chrysosporium were inoculated to soils, and then the faba bean seeds were sown. After 21 days of sowing, the plants were irrigated with water to severe as control, with 100 mg L⁻¹ of Cd and 200 mg L⁻¹ of Pb. The results show that Cd and Pb caused a significant reduction in morphological characteristics, auxin, gibberellins, photosynthetic pigments, minerals content, and antioxidant enzymes as compared to control plants but caused a substantial boost in abscisic acid, ethylene, electrolyte leakage, lipid peroxidation, glutathione, proline, superoxide dismutase, secondary metabolites, and antioxidant capacity. In inoculated plants, metal-induced oxidative stress was modulated by inhibiting the transport of metal and decreased electrolyte leakage and lipid peroxidation. Finally, the inoculation of endophytic fungi contributed actively to the absorption of heavy metals and decreased their content in soil and plants. This could be utilized as an excellent technique in the fields of heavy metal–contaminated sustainable agriculture.

The DNA damage and cytotoxicity induced by CdCl₂ solutions and soils anthropogenically contaminated with heavy metals were studied using the micronucleus (MN) test. Vicia faba, a plant model widely used in liquid exposure assays, was adapted for direct exposure to a solid phase. In addition, the MN assay was adapted to a new wild plant system, the white clover (Trifolium repens). The results obtained after exposure to CdCl₂ solutions confirmed that V. faba root cells were a sensitive model and revealed that T. repens root cells were not appropriate for the detection of micronuclei (although they were highly sensitive to the cytotoxic effect of CdCl₂). Concerning the results observed after direct exposure to contaminated soils (solid-phase exposure), the MN frequency scores in V. faba root cells were increased in a statistically significant and dose-related manner compared to the control plants. Regarding T. repens root cells, this solid phase exposure confirmed that this model is not appropriate for use in the micronucleus assay.

Irrigation of crops with microcystins (MCs)-containing waters—due to cyanobacterial blooms—affects plant productivity and could be a way for these potent toxins entering the food chain. This study was performed to establish whether MC-tolerant rhizobia could benefit growth, nodulation, and nitrogen metabolism of faba bean plants irrigated with MC-containing waters. For that, three different rhizobial strains—with different sensitivity toward MCs—were used: RhOF96 (most MC-sensitive strain), RhOF125 (most MC-tolerant strain), or Vicz1.1 (reference strain). As a control, plants grown without rhizobia and fertilized by NH₄NO₃ were included in the study. MC exposure decreased roots (30–37 %) and shoots (up to 15 %) dry weights in un-inoculated plants, whereas inoculation with rhizobia protects plants toward the toxic effects of MCs. Nodulation and nitrogen content were significantly impaired by MCs, with the exception of plants inoculated with the most tolerant strain RhOF125. In order to deep into the effect of inoculation on nitrogen metabolism, the nitrogen assimilatory enzymes (glutamine synthetase (GS) and glutamate synthase (GOGAT)) were investigated: Fertilized plants showed decreased levels (15–30 %) of these enzymes, both in shoots and roots. By contrast, inoculated plants retained the levels of these enzymes in shoots and roots, as well as the levels of NADH-GOGAT activity in nodules. We conclude that the microcystin-tolerant Rhizobium protects faba bean plants and improves nitrogen assimilation when grown in the presence of MCs.

Veterinary antibiotics introduced into soil environment may change the composition and functioning of soil microbial communities and promote the spreading of antibiotic resistance. Actual risks depend on the antibiotic’s bioaccessibility and sequestration in soils, which may vary with contact time and soil properties. We elucidated changes in the horsebean plant’s bioaccessible oxytetracycline with increasing contact time in three different soils (cinnamon, red, and brown soil) and observed discrepancy in oxytetracycline dissipation using sequential extractions with H₂O-, 0.01 M CaCl₂-, and Mcllvaine- in the same three soils. The results showed lower quantities of oxytetracycline with increasing contact time over 20 days than the level in freshly contaminated soils but hugely discrepant quantities among the three tested soils. In addition, aging largely reduced dissipation of H₂O-, 0.01 M CaCl₂-, and Mcllvaine- extracted oxytetracycline in soils before planting. However, bioturbation helped increase the H₂O-, CaCl₂-, and Mcllvaine- extracted oxytetracyline from cinnamon and brown soils with aging. Lastly, correlation analysis indicated that bioaccessibility of oxytetracycline significantly correlates with the total of H₂O-, CaCl₂-, and Mcllvaine- extracted oxytetracycline (0.676**, p < 0.01) in soils, especially the H₂O- (0.789**, p < 0.01) and Mcllvaine- (0.686**, p < 0.01) extracted oxytetracycline with aging. Overall, this study provides some basic understanding of the aging effect on sequestration and bioaccessibility of veterinary antibiotics in soils.

A field trial was carried out to examine the influence of residual acidified biochar (a 3:100 (w/w) mixture of citric acid and citrus wood biochar) on soil properties, growth, water status, photosynthetic efficiency, metal accumulation, nutrition status, yield, and irrigation use efficiency (IUE) of maize grown under salty soil and metal-contaminated irrigation water. The acidified biochar (ABC) was applied to faba bean in 2016/2017 in saline soil (electrical conductivity (ECe) 7.6 dS m⁻¹) with three levels 0, 5, and 10 t ha⁻¹ with 4 replications. The results summarized that after a year of utilization, acidified biochar still significantly affected the growth and yield by improved soil properties and decreased maize uptake of sodium by transient sodium (Na⁺) binding because of its high adsorption capacity. Growth, physiology, and maize yields were influenced positively by ABC application, under metal-contaminated irrigation water. It was summarized that the utilization of ABC had a significant residual (P ≤ 0.05) effect on reducing nickle (Ni), lead (Pb), cadmium (Cd), and chromium (Cr) accumulation in maize under heavy metal–contaminated irrigation water. However, more detailed open-field experiments should be carried out to assess the long-term residual impacts of ABC for sustaining maize production under biotic stress.