Legislative aspects of pesticide regulations

Abstract

This paper reviews the development of pesticides as an agricultural and health tool and discusses the national and international implications of pesticide regulation. The need for scientific input to the legislative and regulative processes is explained. Appropriate legislation and regulatory structures are presented. Finally, the need for international cooperation in the use and control of pesticides is analyzed.     

Trace element content in tea brewed in traditional metallic and stainless steel teapots

The migration of metals in tea brewed in metallic teapots was investigated. The teapots were obtained from North Africa stores in Brussels in 2005–2006 and in 2011. Chinese gunpowder green tea, the most commonly used tea in the Moroccan community, was used to prepare the tea. Tea brewed in metallic teapots was compared to tea brewed in a glass vessel in order to evaluate the contribution of the tea and the teapots to the metal concentrations in the brewed tea. Tea samples were also collected in Moroccan households and in tearooms in Brussels. The elements As, Cd, Pb, Sn, Mn, Fe, Cr, Co, Ni, Cr, Cu, Zn, and Al were analyzed by high-resolution sector field inductively coupled mass spectrometry. The relationship between the metal composition of the alloy of the teapot and the metal concentration in tea was also investigated. Migration of Pb and to a lesser amount Ni, Cu, and Zn was observed in brass teapots and migration of Cd from a number of stainless steel teapots was observed. The soldering connecting the sprout to the teapot was shown to be an important source of Pb to the tea. High levels of Mn and Al were also observed in the brewed tea and these elements where shown to originate from the tea itself. Metal exposure from tea drinking was calculated for different tea consumption levels and different metal concentration levels and compared to toxicological reference values.     

Characterization of phosphogypsum wastes associated with phosphoric acid and fertilizers production

The present work is directed to characterize the phosphogypsum (PG) wastes associated with phosphoric acid produced by the wet process in industrial facility for the production of fertilizers and chemicals in Egypt. The PG waste samples were characterized in terms of spectroscopic analysis (X-ray diffraction, X-ray fluorescence, IR spectra) and radiometric analysis (γ- and α-measurements). The γ-ray measurements showed that the average activity concentrations are 140 ± 12.6, 459 ± 36.7, 323 ± 28.4, 8.3 ± 0.76 and 64.3 ± 4.1 Bq/kg for U-238, Ra-226, Pb-210, Th-232 and K-40, respectively. The α-particle measurements of uranium isotopes showed that the average activity concentrations of U-238, U-235 and U-234 were 153 ± 9.8, 7 ± 0.38, 152 ± 10.4 Bq/kg, respectively. The average radiochemical recovery (%) of the destructive α-particle measurements is ∼70% with a resolution (FWHM) of ∼30 keV. Activity ratios of U-238/Ra-226 and U-238/Pb-210 were less than unity (i.e., <1) and equal to 0.31 ± 0.02 and 0.47 ± 0.16, respectively. The isotopic ratios of U-238/U-235 and U-238/U-234 (in PG and PR samples) were close to the normal values of ∼21.7 and ∼1, respectively and are not affected by the wet processing of phosphate rock (PR). The obtained results of PG waste samples were compared with phosphate rock (PR) samples. The radiation hazard indices are namely, radium activity index (Ra-Eq > 370 Bq/kg), total absorbed gamma dose rate (D_γr > 5 nGy/h) and radon emanation fraction (Rn-EF > 20%). Uncertainty of the sample counting was 95% confidence level of σ. The results indicated the necessity to find suitable routes to decrease and/or redistribute the radionuclide of environmental interest (i.e., Ra-226) in PG wastes, consequently to reduce its radiation impacts in the surrounding environment.     

Effect of initial sulfide concentration on sulfide and phenol oxidation under denitrifying conditions

The objective of this work was to evaluate the effect of the initial sulfide concentration on the kinetics and metabolism of phenol and sulfide in batch bioassays using nitrate as electron acceptor. Complete oxidation of sulfide (20 mg L(-1) of S(2-)) and phenol (19.6 mg L(-1)) was linked to nitrate reduction when nitrate was supplemented at stoichiometric concentrations. At 32 mg L(-1) of sulfide, oxidation of sulfide and phenol by the organo-lithoautotrophic microbial culture was sequential; first sulfide was rapidly oxidized to elemental sulfur and afterwards to sulfate; phenol oxidation started once sulfate production reached a maximum. When the initial sulfide concentration was increased from 20 to 26 and finally to 32 mg L(-1), sulfide oxidation was inhibited. In contrast phenol consumption by the denitrifying culture was not affected. These results indicated that sulfide affected strongly the sulfide oxidation rate and nitrate reduction.     

Synthesis of Polyurethane and Characterization of its Composites Based on Alfa Cellulose Fibers

Polyurethane (PU) based on polycaprolactone (PCL) and 4,4′ diphenyl methylene diisocyanate (MDI) was synthesized using a two-step method. The PU obtained was then blended with various amounts of cellulose extracted from alfa stems to prepare composite materials. The influence of cellulose on the thermal and mechanical properties of different composites was demonstrated by means of several characterization techniques such as Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), scanning electron microscopy (SEM)…     

Externalities of Fugitive Dust

It is known that fugitive dust can cause human health and environmental problems, alone or in combination with other air pollutants. These problems are referred to as ‘external costs’ that have been traditionally ignored. However, there is a growing interest towards quantifying externalities to assist policy and decision-making. With this in mind, the present study aimed at discussing the environmental regulations that deal with fugitive dust, the impact of fugitive dust on human health and global climate system, and the available methods for calculating fugitive dust externalities. The damage cost associated with human health and global environmental problems was predicted based on the environmental strategy priority model. The damage cost estimated by the model ranged from 40 to 374 EUR/kg of emitted fugitive dust with a mean value of 120 EUR/kg of emitted fugitive dust. It was also found that PM_2.5 and PM₁₀ have contributed to about 60% and 36% of the estimated damage cost, respectively. The remaining 4% was attributed to both nitrate and sulfate aerosols.     

Spatial variability of isoproturon mineralizing activity within an agricultural field: geostatistical analysis of simple physicochemical and microbiological soil parameters

We assessed the spatial variability of isoproturon mineralization in relation to that of physicochemical and biological parameters in fifty soil samples regularly collected along a sampling grid delimited across a 0.36 ha field plot (40 x 90 m). Only faint relationships were observed between isoproturon mineralization and the soil pH, microbial C biomass, and organic nitrogen. Considerable spatial variability was observed for six of the nine parameters tested (isoproturon mineralization rates, organic nitrogen, genetic structure of the microbial communities, soil pH, microbial biomass and equivalent humidity). The map of isoproturon mineralization rates distribution was similar to that of soil pH, microbial biomass, and organic nitrogen but different from those of structure of the microbial communities and equivalent humidity. Geostatistics revealed that the spatial heterogeneity in the rate of degradation of isoproturon corresponded to that of soil pH and microbial biomass.     

Dissipation of S-metolachlor in plant and soil and effect on enzymatic activities

The present study aimed at evaluating the dissipation of S-metolachlor (S-MET) at three doses in maize growing on diverse physico-chemical properties of soil. The effect of herbicide on dehydrogenase (DHA) and acid phosphatase (ACP) activity was estimated. A modified QuEChERS method using LC-MS/MS has been developed. The limit of quantification (0.001 mg kg^?1) and detection (0.0005 mg kg^?1) were very low for soil and maize samples. The mean recoveries and RSDs for the six spiked levels (0.001–0.5 mg kg^?1) were 91.3 and 5.8%. The biggest differences in concentration of S-MET in maize were observed between the 28th and 63rd days. The dissipation of S-MET in the alkaline soil was the slowest between the 2nd and 7th days, and in the acidic soil between the 5th and 11th days. DT₅₀ of S-MET calculated according to the first-order kinetics model was 11.1–14.7 days (soil) and 9.6–13.9 days (maize). The enzymatic activity of soil was higher in the acidic environment. One observed the significant positive correlation of ACP with pH of soil and contents of potassium and magnesium and negative with contents of phosphorus and organic carbon. The results indicated that at harvest time, the residues of S-MET in maize were well below the safety limit for maize. The findings of this study will foster the research on main parameters influencing the dissipation in maize ecosystems.     

Appearance of aldehydes in the surface layer of lake waters

The paper presents results concerning the changes in the content of aldehydes in samples of lake water collected near the lake surface. The study of lake waters was undertaken to explain which physicochemical parameters of the environment have the greatest influence on the level of aldehydes, which of the aldehydes are most often met in surface water and in what concentrations. We observed that formaldehyde, acetaldehyde, propanal, glyoxal, methylglyoxal and acetone were commonly present in surface water samples, while semi-volatile and poorly soluble aldehydes such as nonanal and decanal were observed seasonally. The contents of total aldehydes varied in a wide range, from 55 to 670 μg/l, and the concentration of total organic carbon varied significantly from 3 to 18 mg /l, but there was no evident correlation between them in all of samples. The total content of aldehydes did not depend on the meteorological parameters such as air temperature, UV radiation and ozone concentration; however, it was noted that the level of carbonyl concentration is related to the period of intense precipitation: in the period of very low precipitations, the highest contents of total aldehydes were determined in all of the water samples, and in the periods of intense precipitations, the content of total aldehydes was drastically smaller.