The presence of heavy metals in food is a threat to human health. Exposure to heavy metals as a result of consumption of contaminated vegetables, as well as their toxicity, is a serious problem. Different branches of industry and the road traffic have a significant impact on environmental pollution with heavy metals. Municipal and industrial sewage also is an important source of those substances. Furthermore, the mineral content of vegetables depends on factors such as the natural content of trace elements in the environment, their levels in mineral fertilizers, and fertilizer doses. In the soil, a natural source of these metals is bedrock. In soils used for agricultural purposes, some quantities of metals are introduced together with fertilizers, both organic and mineral. Additionally, another sources of the metals are plant protection products. Heavy metal dynamics in the soil and their uptake by plants are influenced by soil properties, which play a key role in the bioavailability of these metals. Metal mobility and assimilation are also influenced by the addition of organic and inorganic matter. A significant body of evidence also suggest that the age of the soil plays an important role in modulation of metal bioavailability to plants. Apart from being influenced by the soil-related factors, absorption of metals differs in different types of plants. A significant variation in metal concentrations was also found depending on their location in plant tissues, on plant species, or even on varieties of the same species.

We examined the susceptibility of the worker honeybee Apis mellifera L. to pyrethroids. Bees were intoxicated by selected synthetic pyrethroids (active substances: beta-cyfl uthrin, deltamethrin, alphacypermethrin, lambda-cyhalothrin, esfenvalerate, and bifenthrin) and 72 hours after intoxication the number of surviving insects was determined. It was observed that the susceptibility of the honeybee to pyrethroids (expressed herein as the survival rate) was changing in diurnal rhythm, ranging from 100% (for a majority of substances in both seasons) to 11.1±0.37% (deltamethrin) and 11.1±0.73% (esfenvalerate) in spring, and 11.1±0.73% (esfenvalerate) and 4.6±0.17% (bifenthrin) in summer. The lowest susceptibility of bees to pyrethroids occurred during the night, when the honeybees were characterized by reduced motility and did not fl y out for foraging, whereas the highest susceptibility was observed during the day, a natural time for seeking food. Along with diurnal changes in the susceptibility described above, differences dependent on the seasons in which the intoxication took place were also observed. Insects intoxicated in summer were less susceptible to pyrethroids than those intoxicated in spring.

The supervised field trials were conducted in a commercial apple orchard in 2016. The trials were an attempt to determine a model for dissipation and toxicological evaluation of fluopyram, tebuconazole, captan, tetrahydrophthalimide (THPI), pirimicarb, spirodiclofen, and boscalid residues detected in fruit of Red Jonaprince, Lobo, and Gala varieties immediately before harvest. The analysis also covered amounts of pesticides still present in remnants of calyx in Lobo and Gala varieties immediately before harvest. Laboratory samples of ripe apples were collected within 14 days of the treatment. Levels of pesticide residues detected in the samples changed at a constant exponential rate, and the residue levels found in ripe apples of Red Jonaprince, Gala, and Lobo varieties immediately before harvest were below maximum residue levels (MRL). Overall, captan residues in remnants of calyx were at a level of 22.3% for the Gala variety and 9.3% for the Lobo variety. Likewise, the long-term daily intake of the detected substances by a Polish adult consumer was low, ranging from 0.02% ADI for pirimicarb to 0.72% ADI for captan.

The study concerned dissipation of metazachlor and clomazone, herbicides widely used in rapeseed (Brassica napus L. subsp. napus) protection, applied to the clay soil under field and laboratory conditions. Furthermore, the uptake of these pesticide from soil by rapeseed plants was investigated under field conditions. An additional aim of this work was to modify the QuEChERS method for the determination of metazachlor and clomazone in the plant material. Analytical procedures for metazachlor and clomazone qualification and quantification in rapeseed plants and soil were developed, using gas chromatography with an micro electron capture detector (GC-μECD) and a mass detector (GC-MS/MS QqQ) as confirmation. Dissipation kinetics of herbicide residues in soil were described as first-order equations. The analytical performance was very satisfactory and confirmed that the methods meet the requirements of the European Commission. In the conducted field experiments it was found that dissipation of clomazone and metazachlor in clay soil follows first-order kinetics (R 2 between 0.964 and 0.978), and half-lives were 9.5 days and 10.2 days for clomazone and metazachlor, respectively. Under laboratory conditions, dissipation of clomazone and metazachlor in soil also follows first-order kinetics (R 2 between 0.937 and 0.938), and half-lives were 8.8 days and 5.7 days for clomazone and metazachlor, respectively. Residues of both herbicides in rape plants 22 days after application of herbicides were below the maximum residue levels for Brassica plants. Metazachlor and clomazone dissipate very fast in clay soil and their uptake by rape plants is very low.

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Biological crop protection is recommended to be applied alternately or together with chemical one, to protect human health from the excessive use of toxic pesticides. Presence of microorganisms can influence the concentration of chemical pollutants in soil. The aim of this study is to estimate the influence of a commercial biological fungicide containing Trichoderma harzianum Rifai T-22 on dissipation kinetics and degradation of five herbicides belonging to different chemical classes: clomazone, fluazifop-P-butyl, metribuzin, pendimethalin, and propyzamide, in two types of soil. Results of the study revealed that T. harzianum T-22 influences pesticide degradation and dissipation kinetics of the non-persistent herbicides: clomazone, fluazifop-P-butyl, and metribuzin. In soil with a higher content of nitrogen, phosphorus, and organic matter, degradation increased by up to 24.2%, 24.8%, and 23.5% for clomazone, fluazifop-P-butyl, and metribuzin, respectively. In soil with lower organic content, degradation was on a low level, of 16.1%, 17.7%, and 16.3% for clomazone, fluazifop-P-butyl, and metribuzin, respectively. In our study, the addition of the biological preparation shortened herbicide dissipation half-lives, from 0.3 days (2.9%) for fluazifop-P-butyl, to 18.4 days (25.1%) for clomazone. During the degradation study, no significant differences were noticed for pendimethalin, belonging to persistent substances. Biological protection of crops can modify pesticide concentrations and dissipation rates. On one hand, this may result in the reduced effectiveness of herbicide treatments, while on the other, it can become a tool for achieving cleaner environment.

Field studies were conducted to evaluate the transfer of active ingredients (AIs) of plant protection products (PPPs) to beehives. They were applied in two commodity red raspberry plantations of two varieties: Laszka (experiment 1) and Seedling (experiment 2). Samples of flowers, leaves, bees, brood, and honey were examined for the presence of chlorpyrifos, cypermethrin, difenoconazole, cyprodinil, and trifloxystrobin (experiment 1) and chlorpyrifos, boscalid, pyraclostrobin, cypermethrin, difenoconazole, and azoxystrobin (experiment 2). In experiment 1, the highest levels of trifloxystrobin were observed on the surface of flowers, (0.04 μg/flower) and for difenoconazole on the inside (0.023 μg/flower). Leaves contained only trace residues of cypermethrin and cyprodinil (0.001 μg/cm2 of leaves each) and trifloxystrobin (0.01 μg/cm2 of leaves) on the surface; inside the leaves, the highest levels of trifloxystrobin were observed (0.042 μg/cm2 of leaves). In experiment 2, boscalid was found on the surface and inside the flowers and leaves (0.063 and 0.018 μg/flower and 0.057 and 0.033 μg/cm2 of leaves, respectively). In bees, brood, and honey (experiment 1), chlorpyrifos was present in the highest quantity (7.3, 1.6, and 4.7 μg/kg, respectively). Additionally, cypermethrin and trifloxystrobin were found in bees, and trifloxystrobin was present in honey. Bees, brood, and honey from plantation 2 contained all studied AIs, with the highest levels of boscalid (28.6 μg/kg of bees, 37.0 μg/kg of brood, and 33.9 μg/kg of honey, respectively). In no case did the PPP residues in honey exceed acceptable maximum residue levels (MRLs)—from a formal and legal point of view, in terms of the used plant protection products, the analysed honey was fit for human consumption.

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