Probability of misclassifying biological elements in surface waters

Measurement uncertainties are inherent to assessment of biological indices of water bodies. The effect of these uncertainties on the probability of misclassification of ecological status is the subject of this paper. Four Monte-Carlo (M-C) models were applied to simulate the occurrence of random errors in the measurements of metrics corresponding to four biological elements of surface waters: macrophytes, phytoplankton, phytobenthos, and benthic macroinvertebrates. Long series of error-prone measurement values of these metrics, generated by M-C models, were used to identify cases in which values of any of the four biological indices lay outside of the “true” water body class, i.e., outside the class assigned from the actual physical measurements. Fraction of such cases in the M-C generated series was used to estimate the probability of misclassification. The method is particularly useful for estimating the probability of misclassification of the ecological status of surface water bodies in the case of short sequences of measurements of biological indices. The results of the Monte-Carlo simulations show a relatively high sensitivity of this probability to measurement errors of the river macrophyte index (MIR) and high robustness to measurement errors of the benthic macroinvertebrate index (MMI). The proposed method of using Monte-Carlo models to estimate the probability of misclassification has significant potential for assessing the uncertainty of water body status reported to the EC by the EU member countries according to WFD. The method can be readily applied also in risk assessment of water management decisions before adopting the status dependent corrective actions.     

Behavior of fluopyram and tebuconazole and some selected pesticides in ripe apples and consumer exposure assessment in the applied crop protection framework

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.     

Characterization of PM10 and PM2.5 and associated heavy metals at the crossroads and urban background site in Zabrze, Upper Silesia, Poland, during the smog episodes

The concentrations of seven heavy metals (Cd, Cr, Cu, Fe, Mn, Ni, and Pb) associated with PM10 and PM2.5 at the crossroads and the background sites have been studied in Zabrze, Poland, during smog episodes. Although the background level was unusually elevated due to both high particulate emission from the industrial and municipal sources and smog favorable meteorological conditions, significant increase of the concentration of PM2.5 and PM10 as well as associated heavy metals in the roadside air compared to the urban background has been documented. The average daily difference between the roadside and corresponding urban background aerosol concentration was equal to 39.5 μg m^???3 for PM10 and 41.2 μg m^???3 for PM2.5. The highest levels of the studied metals in Zabrze appeared for iron carried by PM10 particles: 1,706 (background) and 28,557 ng m^???3 (crossroads). The lowest concentration level (in PM10) has been found for cadmium: 7 and 77 ng m^???3 in the background and crossroads site, respectively. Also the concentrations of heavy metals carried by the fine particles (PM2.5) were very high in Zabrze during the smog episodes. Concentrations of all studied metals associated with PM10 increased at the roadside compared to the background about ten times (one order) while metals contained in PM2.5 showed two to three times elevated concentrations (except Fe—five times and Cr—no increase).     

Influence of formulation on mobility of metazachlor in soil

The mobility of metazachlor [2-chloro-N-(pyrazol-1-ylmethyl)acet-2′,6′-xylidide] in sand soil and loamy sand soil was studied in a soil column under laboratory conditions. Commercial metazachlor formulation (Metazachlor 500 suspension concentrate (SC)) and metazachlor immobilized in alginate matrix were used for leaching experiment. The initial concentration of metazachlor in soil for both formulations was 2.0 mg mL^?1. After application of herbicide, the columns were irrigated with 100, 40, and 3.7 mm of water. After 1 h, when addition of water was completed, soils were sampled in 5-cm segments and were used for the analysis of residues. The use of alginate controlled release (CR) formulation reduced the vertical mobility of metazachlor into soil layer in comparison with the formulation SC.