Laboratory tests were performed on sandy loamy soil to establish the relations between bacterial diversity, soil enzyme activity and degradation of Amistar 250 SC, Falcon 460 EC and Gwarant 500 SC fungicides. Apart from carrying out microbiological and biochemical analyses, the residues of active substances from the tested fungicides were determined. Structural diversity of was determined based on the next-generation sequencing (NGS) method, and fungicide residues the liquid chromatography tandem-mass spectrometry (LC-MS/MS). It was found that changes in bacterial diversity occurred in the soil subject to fungicide treatment, particularly at the family and genus level. Proteobacteria, Firmicutes and Actinobacteria were prevailing in all soil samples. Bacillus occurred both in the control soil and in the soil treated with fungicides, while Pseudonocardia occurred only in the fungicide-treated soil. Of all the fungicides tested, the biggest changes in bacterial diversity were caused by Gwarant 500 SC. The preparations tested not only affected the composition of soil microbiota, but also contributed to changes in the biochemical properties of soil by inhibiting the activity of almost all tested enzymes, with the exception of alkaline phosphatase and β-glucosidase. Chlorothalinil was the fastest degraded in the soil and spiroxamine at the slowest.
The first aim of this paper was to evaluate pesticide residue levels of berry fruit samples. The second aim was to analyze health risks associated with pesticide levels. The monitoring was conducted on samples from producers in north-eastern Poland, during the time period 2005-2010. In total, 241 samples of berry fruit were analyzed using validated and accredited multi residue methods. The studies included 7 commodities (125 strawberry, 59 black currant, 25 raspberry, 23 chokeberry, 7 red currant samples and one sample of elderberry and wild strawberry), and the analysis of 128 pesticides. Residues, mainly insecticides, were found in 47.7% of samples while 40.7% of samples contained pesticide residues below MRLs and 7% above MRLs. The pesticides were found most often in red currant (100%) and black currant (63%) samples. The most frequently detected pesticides were fenazaquin and fenitrothion. Pesticide residues at levels exceeding legally binding MRLs occurred mostly in black currant samples (12 samples). Violations of the maximum residue limits (MRLs) (15 notifications) and use of a forbidden plant protection product (8 notifications) were found in twenty-three berry samples during the six-year study. For these cases, the RASFF system (rapid alert system for food and feed) procedures were initiated. The highest number of notifications was recorded in 2008 (11 notifications). Only one of the notifications was prepared for berry fruit from an integrated production system − black currant, the remaining were for conventional fruit. Among the RASFF notifications, 17 (74%) were for black currant samples.
The estimated exposure to pesticide residues detected in the analyzed berry fruit samples was shown to be very low for the general population (adults) and for the critical population of small children. Acute and chronic exposure based on residue levels did not adversely affect consumer health.