In recent years, researches on the impact of nanometals on the state of soil ecosystems, including silicon, which is known to have a positive effect on plants under stressful conditions, have become relevant. The aim of this study was to assess the biological effects of nanoparticles (NP) of SiO₂ on the plant Solanum tuberosum. Testing of biological activity of NP SiO₂ on potato tubers was carried out on the example of five concentrations of metal increasing exponentially (0.03, 0.09, 0.18, 0.21, and 0.36 g/kg of potatoes) and control (without processing of NP SiO₂). We have shown that on the 21st day of the experiment after tuber treatment, the average mass of tuber in concentrations 0.18 and 0.21 g/kg of NP SiO₂ increased by 6.6% and 2.2%, respectively; stimulation of root length by 27.8–21.0%, the length of sprouts increased to 55.3%, and at a concentration of 0.36 g/kg on the 14th and 45th days, there was a maximum accumulation of Si in different parts of the plants. Analysis of chlorophyll content in the sprouts Solanum tuberosum showed that concentrations of nanoform SiO₂ 0.03–0.21 g/kg chlorophyll were higher than control by 48.8% and content of carotenoids by 29.7%. According to the results of field studies, the maximum mass of potato stems and tubers was observed at concentrations of 0.09 g/kg and 0.18 g/kg NP SiO₂, which confirmed the absence of toxic properties of NP SiO₂. The absence of the toxic effect of the investigated range of concentrations of NP SiO₂ from 0.03 to 0.36 g/kg was also confirmed by electrophoretic mobility of plant DNA molecules after incubation with silicon nanoparticles in vitro.

Although growing vegetables in urban gardens has several benefits, some questions in relation with the safety of foods remain when the self-production is carried out on highly contaminated garden soils. To better assess the local population’s exposure to Cd and Pb induced by the past activities of a lead smelter, a participatory program was initiated in 115 private kitchen gardens located in northern France to assist gardeners in understanding their soil environment. The challenge included contributing to the database of urban garden soils with the collection of a large number of samples: 1525 crops grouped into 12 types (leaf, fruiting, root, stem and bulbous vegetables, tubers, cabbages, leguminous plants, celeriac, fresh herbs, fruits, and berries), 708 topsoils, and 52 samples of self-produced compost. The main results were as follows: (i) topsoils were strongly contaminated by Cd and Pb compared to regional reference values; (ii) great variability in physicochemical parameters and metal concentrations in topsoils; (iii) the highest concentrations of Cd and Pb for celeriac and fresh herbs and the lowest for fruits and fruiting vegetables; (iv) a high percentage of vegetables that did not comply with the European foodstuff legislation; and (v) most self-produced compost samples were strongly contaminated. This study aimed to raise awareness and generate functional recommendations to reduce human exposure and to provide useful data that could be considered in other environmental contexts.

Two field trials were carried out in two successive agricultural seasons to study the possibility of using silicon (Si) and Moringa seed extract (MSE) for reducing heavy metal contamination resulting from phosphate fertilizers addition to potato tubers. A randomized complete block design experiment was performed using three replicates. Various sources of phosphate fertilizers as ordinary super phosphate and rock phosphate were added at rate of 100 kg P ha⁻¹ prior sowing. Silicon was added as potassium silicate (20% SiO₂) at rate of 6 L ha⁻¹, and MSE was also added at rate of 150 L ha⁻¹ in three equal doses with the 2nd, 4th, and 6th irrigations during the last 10 min of drip irrigation. Results indicated that the addition of phosphate fertilizers increased fresh tuber yield, dry weight yield, NPK uptake, catalase, peroxidase, superoxide dismutase, and glutathione reductase of potato either alone or combined with silicon and MSE. The accumulation rate of Cu, Cd, and Ni in potato was higher with the single addition of rock phosphate fertilizer compared with single addition of super phosphate fertilizer. The highest reduction (P < 0.05) in heavy metal accumulation in potato leaves and tubers as well as soil was found with MSE treatment plus super phosphate fertilizer. It is recommended to add MSE at a rate of 150 L ha⁻¹ along with fertilizing the potato crop with ordinary super phosphate fertilizer.

A study was conducted in fluoride-affected Bankura and Purulia districts of West Bengal to assess the potential health risk from fluoride exposure among children, teenagers, and adults due to consumption of rice, pulses, and vegetables in addition to drinking water and incidental ingestion of soil by children. Higher mean fluoride contents (13–63 mg/kg dry weight) were observed in radish, carrot, onion bulb, brinjal, potato tuber, cauliflower, cabbage, coriander, and pigeon pea. The combined influence of rice, pulses, and vegetables to cumulative estimated daily intake (EDI) of fluoride for the studied population was found to be 9.5–16%. Results also showed that intake of ivy gourd, broad beans, rice, turnip, fenugreek leaves, mustard, spinach, and amaranth grown in the study area is safe at least for time being. The cumulative EDI values of fluoride (0.06–0.19 mg/kg-day) among different age group of people of the study area were evaluated to be ~10⁴ times higher than those living in the control area; the values for children (0.19 and 0.52 mg/kg-day for CTE and RME scenarios, respectively) were also greater than the “Tolerable Upper Intake Level” value of fluoride. The estimated hazard index (HI) for children (3.2 and 8.7 for CTE and RME scenarios, respectively) living in the two affected districts reveals that they are at high risk of developing dental fluorosis due to the consumption of fluoride-contaminated rice, pulses, and vegetables grown in the study area in addition to the consumption of contaminated drinking water.

A field trial was conducted through 2015 and 2016 growing seasons to study the effect of nitrogen fertilizer sources and foliar spray with molybdenum (Mo), salicylic acid (SA) and their combination on tubers yield, some chemical constituents, nutrients uptake, nitrate accumulation and nitrate reductase activity in potato tubers. N source was added at a rate of 350 kg N ha⁻¹in five equal doses as two different forms, the first is urea and the second is ammonium sulfate plus calcium nitrate equally. SA was sprayed with three rates of 0, 75 and 150 mg l⁻¹. Also, Mo as ammonium molybdate was sprayed using three rates 0, 50 and 100 mg l⁻¹Mo. Both treatments of SA and Mo were applied separately as well as with each other, at three successive times 30, 50 and 70 days after planting of potato plants. Results indicated that the addition of 350 kg N ha⁻¹ as ammonium sulfate and calcium nitrate equally caused a significant elevation (P > 0.05) in fresh weight, chlorophyll b, carotenoids, chlorophyll a, nitrate reductase activity, dry weight and NPK uptake by potato tubers compared with the same amount of nitrogen in the form of urea only. All the aforementioned characteristics were improved with increasing concentration of Mo and/or SA. The highest accumulation of nitrate was recorded under the addition of 350 kg N ha⁻¹ as urea alone. The highest average of all the aforementioned characteristics was observed at the treatment of 350 kg N ha⁻¹ as ammonium sulfate and calcium nitrate equally plus spraying with 100 mg l⁻¹Mo and 150 mg l⁻¹ SA. In contrast, this treatment gave the lowest accumulation of nitrates in potato tubers.

A sensitive and selective method was developed and validated for the determination of pyrethrin residues in turnips (turnip leaves, turnip tubers, and the whole of plant) and cultivated soil using gas chromatography coupled with mass spectrometry (GC-MS). Six major components of pyrethrins (pyrethrin I and II, cinerin I and II, and jasmolin I and II) were separated and identified. The method involving solid-phase extraction (SPE) cleanup led to satisfactory average recoveries (88.1–104%) with limits of quantification (LOQs) of 0.05 mg/kg. The dissipation and final residue of pyrethrins in six provinces (among these places, two experiments were conducted in greenhouse and other four experiments in open filed) in China were studied. The trial results suggested that the half-lives of pyrethrins in the whole of turnips and soil were 0.5–1.6 and 1.0–1.3 days, respectively, and the degradation of pyrethrins in the greenhouse was quicker than that in open fields. The final residues of pyrethrins in turnip leaves and tubers were all below the maximum residue limit (MRL) established by the EU (1.0 mg/kg). A pre-harvest interval of 2 days and MRL of 1.0 mg/kg are recommended to ensure food safety standards for pyrethrins in turnips. Long-term risk assessment and short-term risk assessment of turnip tubers were evaluated. Hazard quotient (HQ) and acute hazard index (aHI) were significantly less than 100%, indicating negligible risk for consumption of turnip tubers.