Effect of fluoride content in drinking water in Tricity on its concentration in urine of pre‐school children

Fluorides were analysed in drinking water and in urine of pre‐school children from different districts of Tricity (Gdańsk, Gdynia and Sopot). Concentration of fluorides in urine was found to depend on their content in drinking water. The two years (1997–98) study was made for 15 preschool children populations; each numbering in 10–20 individuals. The fluorides were determined by flouroselective electrode potentiometry.     

Simulation of Reflected and Scattered Laser Radiation for Designing Laser Shields

This paper presents a computer simulation of reflected and scattered laser radiation for calculating the angle of laser shields performed with the Laser Shield Solver computer program. The authors describe a method of calculating the shield angle for laser shields which protect workers against reflected and scattered laser radiation and which are made from different materials. The main assumptions of the program, which calculates and simulates reflected laser radiation from any material and which can be used for designing shield angles, are presented. Calculations are compared with measurements of reflected laser radiation. The results for one type of laser and different materials which interacted with a laser beam showed that the Laser Shield Solver was an appropriate tool for designing laser shields and its simulations of reflected laser radiation distribution have practical use.     

Efficiency of Filtering Materials Used in Respiratory Protective Devices Against Nanoparticles

The basic aim of this research was to establish the efficiency of filtering materials widely used in respiratory protection devices with particular interest in their porosity, degree of electric and changeable process parameters, such as the flow rate of the test nanoaerosol and the size range of nanoparticles. Tests were carried out with an NaCl solid aerosol of 3.2 × 10⁵ particles/cm³ for the range of particle size of 7–270 nm, at aerosol flow rate of 1800, 2700, 3600, 4500 and 5400 L/h. The tests showed that electrospun nonwovens were the most effective filtering materials for nanoparticles over 20 nm. Melt-blown electret nonwovens with lower porosity than electrospun nonwovens had higher values of penetration of 1%–4%. Those materials provided very efficient protection against nanoparticles of certain sizes only.     

Ecotoxicity evaluation of selected sulfonamides

Sulfonamides (SAs) are a group of antibiotic drugs widely used in veterinary medicine. The contamination of the environment by these pharmaceuticals has raised concern in recent years. However, knowledge of their (eco)toxicity is still very basic and is restricted to just a few of these substances. Even though their toxicological analysis has been thoroughly performed and ecotoxicological data are available in the literature, a systematic analysis of their ecotoxicological potential has yet to be carried out. To fill this gap, 12 different SAs were chosen for detailed analysis with the focus on different bacteria as well as non-target organisms (algae and plants). A flexible (eco)toxicological test battery was used, including enzymes (acetylcholinesterase and glutathione reductase), luminescent marine bacteria (Vibrio fischeri), soil bacteria (Arthrobacter globiformis), limnic unicellular green algae (Scenedesmus vacuolatus) and duckweed (Lemna minor), in order to take into account both the aquatic and terrestrial compartments of the environment, as well as different trophic levels. It was found that SAs are not only toxic towards green algae (EC₅₀ = 1.54-32.25 mg L⁻¹) but have even stronger adverse effect on duckweed (EC₅₀ = 0.02-4.89 mg L⁻¹) than atrazine - herbicide (EC₅₀ = 2.59 mg L⁻¹).     

The effect of alkyl chain length on the degradation of alkylimidazolium- and pyridinium-type ionic liquids in a Fenton-like system

Background, aim, and scope  Ionic liquids are regarded as essentially “green” chemicals because of their insignificant vapor pressure and, hence, are a good alternative to the emissions of toxic conventional volatile solvents. Not only because of their attractive industrial applications, but also due to their very high stability, ionic liquids could soon become persistent contaminants of technological wastewaters and, moreover, break through into natural waters following classical treatment systems. The removal of harmful organic pollutants has forced the development of new methodologies known as advanced oxidation processes (AOPs). Among them, the Fenton and Fenton-like reactions are usually modified by the use of a higher hydrogen peroxide concentration and through different catalysts. The aim of this study was to assess the effect of hydrogen peroxide concentration on degradation rates in a Fenton-like system of alkylimidazolium ionic liquids with alkyl chains of varying length and 3-methyl-N-butylpyridinium chloride. Materials and methods  The ionic liquids were oxidized in dilute aqueous solution in the presence of two different concentrations of hydrogen peroxide. All reactions were performed in the dark to prevent photoreduction of Fe(III). The concentrations of ionic liquids during the process were monitored with high-performance liquid chromatography. Preliminary degradation pathways were studied with the aid of ¹H NMR. Results  Degradation of ionic liquids in this system was quite effective. Increasing the H₂O₂ concentration from 100 to 400 mM improved ionic liquid degradation from 57–84% to 87–100% after 60 min reaction time. Resistance to degradation was weaker, the shorter the alkyl chain. Discussion  The compound omimCl was more resistant to oxidation then other compounds, which suggests that the oxidation rates of imidazolium ionic liquids by OH· are structure-dependent and are correlated with the n-alkyl chain length substituted at the N-1-position. The level of degradation was dependent on the type of head group. Replacing the imidazolium head group with pyridinium increased resistance to degradation. Nonetheless, lengthening the alkyl chain from four to eight carbons lowered the rate of ionic liquid degradation to a greater extent than changing the head group from imidazolium to pyridinium. 1H-NMR spectra show, in the first stage of degradation, that it is likely that radical attack is nonspecific, with any one of the carbon atoms in the ring and the n-alkyl chain being susceptible to attack. Conclusions  The proposed method has proven to be an efficient and reliable method for the degradation of imidazolium ionic liquids by a Fenton-like reagent deteriorated with lengthening n-alkyl substituents and by replacing the imidazolium head group with pyridinium. The enhanced resistance of 1-butyl-3-methylpyridinium chloride when the resistance of imidazolium ionic liquids decreases with increasing H₂O₂ concentration is probably indicative of a change in the degradation mechanism in a vigorous Fenton-like system. H-NMR spectra showed, in the first stage of degradation, that radical attack is nonspecific, with any one of the carbon atoms in the ring and the n-alkyl chain being susceptible to attack. Recommendations and perspectives  Since ionic liquids are now one of the most promising alternative chemicals of the future, the degradation and waste management studies should be integrated into a general development research of these chemicals. In the case of imidazolium and pyridinium ionic liquids that are known to be resistant to bio- or thermal degradation, studies in the field of AOPs should assist the future structural design as well as tailor the technological process of these chemicals     

Ionic liquids as lubricants or lubrication additives: An ecotoxicity and biodegradability assessment

This paper reports on the (eco)toxicity and biodegradability of ionic liquids considered for application as lubricants or lubrication additives. Ammonium- and pyrrolidinium-based cations combined with methylsulphate, methylsulphonate and/or (CF₃SO₂)₂N⁻ anions were investigated in tests to determine their aquatic toxicity using water fleas Daphnia magna, green algae Selenastrum capricornutum and marine bacteria (Vibrio fischeri). Additional test systems with an isolated enzyme (acetylcholinesterase) and isolated leukaemia cells from rats (IPC-81) were used to assess the biological activity of the ionic liquids. These compounds generally exhibit low acute toxicity and biological activity. Their biodegradability was screened according to OECD test procedures 301 B and 301 F. For choline and methoxy-choline ionic liquids ready biodegradability was observed within 5 or 10 d, respectively. Some of the compounds selected have a considerable potential to contribute to the development of more sustainable products and processes.     

Detection and identification of baculovirus pesticides by multitemperature single-strand conformational polymorphism

The method of single-strand conformational polymorphism (SSCP) was modified in our laboratories for the characterization of baculoviruses, insect viruses with great potential for use as bioinsecticides in biological protection programs. A series of primers were synthesized after the comparison of the polyhedrin gene sequences of over 20 baculoviruses. Polyhedrin is a highly conserved protein which is responsible for the persistence of the virus in the environment. Universal primers were designed which could be used in polymerase chain reactions (PCR) containing genomic DNA from an array of nucleopolyhedrosis viruses (NPVs) including these which are used as biopesticides against important pests of forests and crops, such as Anticarsia gemmatalis, Spodoptera frugiperda, Lymantria dispar, Lymantria monacha and many others. PCR products were denatured and subjected to single-strand DNA electrophoresis at variable temperatures (MSSCP) where, after silver staining, they gave ssDNA band patterns characteristic for each baculovirus species. This technique can be potentially applied to detect baculoviruses in insects collected in the field, as well as to plant tissues and the excrements or bodies of predators without need for sequencing the PCR products. Sometimes MSSCP can be used not only for species determination but also as an indication of genomic variability which can be related to infectivity.     

Mixing-controlled biodegradation in a toluene plume--results from two-dimensional laboratory experiments

Various abiotic and biotic processes such as sorption, dilution, and degradation are known to affect the fate of organic contaminants, such as petroleum hydrocarbons in saturated porous media. Reactive transport modeling of such plumes indicates that the biodegradation of organic pollutants is, in many cases, controlled by mixing and therefore occurs locally at the plume's fringes, where electron donors and electron-acceptors mix. Herein, we aim to test whether this hypothesis can be verified by experimental results obtained from aerobic and anaerobic degradation experiments in two-dimensional sediment microcosms. Toluene was selected as a model compound for oxidizable contaminants. The two-dimensional microcosm was filled with quartz sand and operated under controlled flow conditions simulating a contaminant plume in otherwise uncontaminated groundwater. Aerobic degradation of toluene by Pseudomonas putida mt-2 reduced a continuous 8.7 mg L(-1) toluene concentration by 35% over a transport distance of 78 cm in 15.5 h. In comparison, under similar conditions Aromatoleum aromaticum strain EbN1 degraded 98% of the toluene infiltrated using nitrate (68.5+/-6.2 mg L(-1)) as electron acceptor. A major part of the biodegradation activity was located at the plume fringes and the slope of the electron-acceptor gradient was steeper during periods of active biodegradation. The distribution of toluene and the significant overlap of nitrate at the plume's fringe indicate that biokinetic and/or microscale transport processes may constitute additional limiting factors. Experimental data is corroborated with results from a reactive transport model using double Monod kinetics. The outcome of the study shows that in order to simulate degradation in contaminant plumes, detailed data sets are required to test the applicability of models. These will have to deal with the incorporation of existing parameters coding for substrate conversion kinetics and microbial growth.     

Profiles of enzymatic activity in earthworms from zinc, lead and cadmium polluted areas near Olkusz (Poland)

The aim of the study was to determine whether there are signs of adaptation of soil fauna to a gradient of heavy metal contamination. Earthworms Aporrectodea caliginosa, Lumbricus terrestris and Eisenia fetida were collected during the spring and summer of 2000 and 2001 from meadow sites situated between 2 and 32 km from the Bukowno-Olkusz complex of zinc-lead ore mines and smelters. The heavy metal content in the soil near smelters reaches 10,500 mg/kg (d.w.) for Zn, 2600 mg/kg for Pb and 81.9 mg/kg for Cd. The sites differ with respect to species composition of earthworm community, with A. caliginosa being dominant. Complete data was obtained only for A. caliginosa, since other species were not abundant at all investigated sites during the whole period of investigation. The body burdens of Zn, Pb, Cd and Cu in A. caliginosa reached 1500, 100, 220 and 10 microg/g, respectively, in the vicinity of the smelter (2-4 km), and decreased to 400, 2, 36 and 6 microg/g at the most distant site (32 km). Cadmium and lead content was significantly elevated in the whole body of L. terrestris collected at the site 2.5 km distant from the smelters when compared to more distant sites, while in E. fetida only the body burden of cadmium was elevated at the nearest site compared to the next site of transect. Activities of glutathione peroxidase (GPX; EC 1.11.1.9) against hydrogen peroxide (H2O2) or cumene hydroperoxide (cumOOH), glutathione reductase (GR; EC 1.6.4.2), glutathione S-transferase (GST; EC 2.5.1.18) and catalase (CAT; EC 1.11.1.6) were assayed in postmitochondrial supernatant obtained from whole body homogenates. Seasonal and annual variations of enzyme activity were reflected by higher GPX activity in the late summer of 2001 in comparison with the spring and summer of 2000. This may reflect severe drought in the spring and summer of 2000. The activity of both GPX isozymes, GR and GST in A. caliginosa and L. terrestris increased with increasing distance from the smelters and reached maximum at sites III and IV (4 and 8 km from the smelters, respectively) and then it decreased in the animals from site V (32 km). These may be the effects of antagonism between the enzyme inducing and enzyme inhibiting action of smelter emissions, a phenomenon known as a hormetic effect. It is postulated here that this effect is of diagnostic value for metal pollution biomonitoring.     

Meligethes aeneus pollen-feeding suppresses, and oviposition induces, Brassica napus volatiles: beetle attraction/repellence to lilac aldehydes and veratrole

Insect pollination and pollen feeding can reduce plant volatile emissions and future insect floral attraction, with oviposition having different effects. Meligethes aeneus F. (Coleoptera: Nitidulidae), is a pollen-feeding pest beetle of oilseed rape, Brassica napus L. (Brassicaceae). We measured plant VOC emission over 72 h from two types of 24 h M. aeneus exposure to B. napus: pollen feeding vs. flower bud injury and oviposition. The most abundant constitutive volatile organic compounds (VOCs), lilac aldehydes A (LA A) & B (LA B) and veratrole (VER), had 30–40 % reductions from M. aeneus pollen-feeding exposure at 24 h and 50–90 % reductions by 72 h, with greater reductions after bud injury and oviposition. Linalool (LIN), a common herbivore-induced plant volatile (HIPV), emission did not change at 24 h, but was induced six- to sevenfold 48 h after both exposure treatments. By 72 h, LIN had even greater (tenfold) induction after bud injury and oviposition, but no induction from pollen feeding. Three common HIPVs (β-caryophyllene, = βCAR (E)-β-farnesene = EβFAR, and (Z)-β-ocimene = ZβOCI) were progressively induced up to 2.5-fold 72 h after floral bud injury and oviposition. We assayed M. aeneus adult behavioral responses to LA A and B, and VER. Both M. aeneus sexes were attracted to higher concentrations than single plant constitutive emission for these VOCs, but avoided much higher doses. Progressive LA A and B, and VER, emission reductions might help plants (e.g., B. napus) to avoid future interactions with pollen-feeding pest herbivores (e.g., M. aeneus). After bud injury and oviposition, HIPV induction could help plants deter future oviposition and/or attract natural enemies to deposited eggs.