Amtliche Mitteilungen ,

Pesticides in agriculture: are we sustainable yet?

Development of an oligonucleotide-based microarray for the detection of foodborne viruses Abstract Foodborne viral diseases are a major public health problem that poses significant social and economic strains. Human astrovirus (AstV), norovirus (NoV), human rotavirus (RoV), and hepatitis A virus (HAV) are frequently reported foodborne pathogens. The microarray is a molecular diagnostic method that is highly specific and widely used due to its plethora of applications in microbiology. This investigation characterized the development of concurrent diagnostic procedures for AstV, NoV, RoV, and HAV. We employed microarray techniques using specific oligonucleotide probes designed for each target virus and analyzed fluorescent signals by hybridization reaction on chips. The selected oligonucleotide probes yielded strong hybridization signals for target viruses without non-specific reactions to other viruses. The developed microarray platform represents a promising means for detection of a broad range of pathogens and, therefore, could improve the diagnosis of foodborne viruses.

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Exposure to pesticide residues during manual removal of bolting sugar beets: determination of transfer coefficients for worker risk assessment Abstract Plant protection products often leave external residues on crops. Workers can be exposed to these residues when re-entering a recently-treated crop. Therefore, task- and crop-specific transfer coefficients are used to estimate the exposure of workers during re-entry: these relate to the transfer of foliar residues to clothing or skin. In this study, we considered a re-entry task not currently covered by European risk assessments: “manual removal of bolting beets” from sugar beet crops. This task can overlap with pesticide treatment, and it involves extensive contact with crop foliage. Therefore, we conducted a worker exposure study along with a dislodgeable foliar residue study in a sugar beet crop previously treated with a fungicide. We determined residues on the clothing of workers who had manually removed bolting beets, and we propose transfer coefficients that can be used in risk assessments to estimate worker exposure during the task “manual removal of bolting beets”.

Assessing the contamination levels of dried teas and their infusions by polycyclic aromatic hydrocarbons (PAHs) Abstract The occurrence of 16 polycyclic aromatic hydrocarbons (PAHs) in 68 brands of teas, bought in Poland, was surveyed using ultrasonic extraction of dried teas and liquid–liquid extraction of infusions. The extracts were cleaned by solid phase extraction. The instrumental analysis was performed using gas chromatography coupled with mass spectrometry (GC–MS). The total content of 16 PAHs (∑16PAHs) ranged from 41.5 to 2910.2 μg/kg in dried teas and from 52.9 to 2226.0 ng/L in infusions. Benzo(a)pyrene was found from below limit of quantification to 75.7 μg/kg in dried teas and from limit of detection to 18.7 ng/L in infusions. The least contaminated samples were herbal and fruit teas, while traditional black, green, red, and white teas, i.e. teas made of Camellia sinensis, were more polluted. Positive correlations between dried traditional teas and their infusions were observed. The mean transfer rates of ∑16PAHs from dried materials into water ranged from 2.4 to 25.3%. The total toxicity of the tested teas largely corresponded to the sum of 4 PAHs (∑4PAHs) chosen by the European Food Safety Authority as indicator of PAHs in food. Estimated PAHs uptake and margin of exposure pointed to low health risks associated with drinking tea infusions.

Clothianidin residues in green bean, pepper and watermelon crops and dietary exposure evaluation based on dispersive liquid-liquid microextraction and LC–MS/MS Abstract We developed an analytical method for quantifying clothianidin residues in green bean, pepper and watermelon crops using dispersive liquid-liquid microextraction (DLLME) and liquid chromatography-tandem mass spectrometry; this method was more rapid, sensitive and simple than QuEChERS sample preparation. Method validation indicated that the recovery for clothianidin was 80.8–93.1%, intra-day and inter-day repeatability ranged from 3.32 to 6.11% and 7.77 to 14.74%, respectively, limits of detection ranged from 0.64 to 0.74 µg/kg, and limits of quantification were 2.13–2.47 µg/kg. Matrix-matched calibration was used to compensate for matrix effects. Following application of the recommended dose in field trials, clothianidin dissipation followed first-order kinetics with half-lives of 1.9, 2.07, and 1.87 days in green bean, pepper, and watermelon crops; respective waiting periods of 5.76, 6.18, and 7.87 days after application are suggested for safe consumption. This study indicates the application of clothianidin presents no significant health risk to Egyptian consumers.

Unraveling the feeding dynamics of Chinese mitten crab-based ecosystems using carbon and nitrogen stable isotope techniques Abstract The Chinese mitten crab (CMC) is an economically important species that consumers prefer mainly because of its delightful taste and aroma. The taste of CMC varies depending on its environmental conditions. Consumers prefer lake-sourced crabs to pond-cultured ones, but the production of crabs in lakes is greatly discouraged because of its adverse impacts on the local ecosystem. This study investigates the dynamics of the food web structure and trophic levels (TL) of both lake and pond ecosystems to apply the knowledge of the lake-cultured system to pond-cultured production using the stable isotope ratios of C and N. Furthermore, the TL was estimated and the IsoSource model was used for diet contribution estimates. The results show that the δ13C of the crab in the pond ecosystem (− 22.6 ± 0.3‰) was more enriched than that in the lake ecosystem (− 25.7 ± 0.4‰) indicating a clear distinction (P < 0.05) which is mainly influenced by their diet. The δ15N of the crab obtained from the lake ecosystem was higher (10.6 ± 0.1‰) than that in the pond ecosystem (8.6 ± 0.2‰), which is indicative of the nutritive value of the lake-culture crabs and consumers’ preference for this type. However, 15N compositions of the lake- and pond-cultured crabs did not differ significantly (P > 0.05), suggesting a similar TL. The crabs also occupied higher TL in both ecosystems under consideration, indicating a reliance of crab on the animal matter for food. This study provides more insights for all concerned stakeholders to make an informed decision with respect to the production and consumption of CMC.

Does winter oilseed rape grown from clothianidin-coated seeds affect experimental populations of mason bees and bumblebees? A semi-field and field study Abstract Impacts of neonicotinoid-containing pesticides on pollinators have been heavily debated in recent years. While bees in the field get rarely exposed to lethal concentrations of neonicotinoids applied as seed coating, sublethal levels found in pollen and nectar may affect bee population development. We assessed a realistic and a worst-case scenario of clothianidin exposure to mason bees (Osmia bicornis) and bumblebees (Bombus terrestris) by conducting a small-scale field and semi-field experiment at sites planted with winter oilseed rape. Flight activity, mortality and population development (brood, colony strength and weight) of bumblebees and number of mason bee brood cells were assessed at three locations. We also analysed clothianidin residues in bee-collected pollen and nectar. We detected clothianidin at low concentrations in nectar and pollen; residues in pollen were higher than in nectar but did not exceed a maximum field concentration of 2.7 µg/kg for bumblebees and 4.7 µg/kg for mason bees. Exposure did not result in significant negative impacts on bumblebee colony development and potential reproductive success of mason bees in either semi-field or field setup. During exposure bumblebees in semi-field treatment tunnels were flying less actively than in control tunnels. Bumblebee colonies in treatment tunnels weighed more than control colonies at the end of the experiment. Our findings suggest that field-realistic exposure to oilseed rape grown from clothianidin-treated seeds (10 g clothianidin/kg seeds) poses little risks to mason bees, bumblebees and their population development. However, an impairment of flower visitation under a worst-case scenario may have implications for pollination services and crop production.

Magnetic dispersive solid phase microextraction technique coupled with LC–MS/MS for evaluating content versus label claims in ephedrine-free food supplements Abstract Sport supplements and weight management supplements are prime targets for adulteration. In response to concerns regarding the safety of ephedra-containing food supplements, manufacturers have marketed “ephedra-free” products. Therefore, a rapid and convenient magnetic dispersive solid phase microextraction method is proposed in order to extract ephedrine from complex food supplements. Quantification of ephedrine is accomplished by ion-spray LC–MS/MS using multiple reaction monitoring (MRM) mode. The LC–MS/MS method is validated in the range of 5–100 ng/mg. The proposed procedure is applied to the determination of ephedrine in various food supplements. Sixteen food supplements including sport and weight loss supplements are provided from two local drugstores (Tabriz, Iran). The mean content of the ephedrine, identified in five products, amounted to 1055 ng/mg. The proposed method is reliable and fast for determination of ephedrine content in food supplements.