Phototransformation of the fungicide tebuconazole, and its predicted fate in sunlit surface freshwaters.

The fungicide tebuconazole (TBCZ) is expected to undergo negligible direct photolysis in surface freshwaters, but it can be degraded by indirect photochemistry. TBCZ mainly reacts with hydroxyl radicals and, to a lesser extent, with the triplet states of chromophoric dissolved organic matter (3CDOM*). Indirect photochemistry is strongly affected by environmental conditions, and TBCZ lifetimes of about one week are expected in sunlit surface waters under favourable circumstances (shallow waters with low concentrations of dissolved organic carbon, DOC, during summer). In these cases, the time trend would follow pseudo-first order kinetics (mono-exponential decay). Under less favourable conditions, photoinduced degradation would span over a few or several months, and TBCZ phototransformation would depart from an exponential trend because of seasonally changing sunlight irradiance. The TBCZ phototransformation products should be less toxic than their parent compound,thus photodegradation has potential to decrease the environmental impact of TBCZ. Hydroxylation is a major TBCZ transformation route, due to either OH attack, or one-electron oxidation sensitised by 3CDOM*, followed by reaction of the oxidised transient with oxygen and water.

Ivermectin Plasma Concentration in Iberian Ibex (Capra pyrenaica) Following Oral Administration: A Pilot Study.

Sarcoptic mange is considered the main driver of demographic declines occurred in the last decades in Iberian ibex (Capra pyrenaica) populations. Mass treatment campaigns by administration of in-feed acaricides are used as a measure to mitigate the impact of mange in the affected populations. However, there are no data on ivermectin (IVM) pharmacokinetics in this wild caprine, and the treatment through medicated feed is not endorsed by evidence on its effectiveness. The aim of this study is to determine the pharmacokinetic profile of IVM in plasma samples of ibexes after the experimental oral administration of IVM, using high performance liquid chromatography (HPLC) with automated solid phase extraction and fluorescence detection. A dose of 500 µg of IVM per body weight was orally administered in a feed bolus to nine healthy adult ibexes (seven males and two females). Blood samples were collected by jugular venipuncture into heparin-coated tubes at day 1, 2, 3, 4, 7, 10, 15, and 45 post-administration (dpa). The highest plasma concentration of IVM (Cmax = 3.4 ng/ml) was detected 24 h after the oral administration (T1), followed by a rapid decrease during the first week post-administration. Our results reveal that plasma IVM concentration drops drastically within 5 days of ingestion, questioning the effectiveness of a single in-feed dose of this drug to control sarcoptic mange. To the best of our knowledge, this is the first study on plasma availability of oral IVM in ibexes and in any wild ungulate species.

A preliminary study on the treatment of human blood soiled stubs, in presence of GSR particles.

In the investigation of gunshot deaths, Bloodstains Pattern Analysis (BPA) and, in particular, backspatter patterns found on the body of the suspect/victim and on the surfaces close to the entrance wound of the bullet can provide investigators with important indications on the dynamics of the events. Backspatter patterns have, however, morphological characteristics common to other bloodstains of different origin, so, in order to positively identify them, a possible solution is represented by their sampling, using an aluminum stub for electron microscopy, for the detection of gunshot residues (GSR) present. The latter, however, if present below the small blood crusts, could be difficult to detect during analysis by Scanning Electron Microscopy/Energy Dispersive X-ray microanalysis (SEM/EDX). In this preliminary study we propose the treatment of the stub surface with a solution based on sodium hypochlorite and calcium chloride, in order to remove/reduce the blood crusts present on the stub surface.

From gaseous HCN to nucleobases at the cosmic silicate dust surface: an experimental insight into the onset of prebiotic chemistry in space.

HCN in the gas form is considered as a primary nitrogen source for the synthesis of prebiotic molecules in extraterrestrial environments. Nevertheless, the research mainly focused on the reactivity of HCN and its derivatives in aqueous systems, often using external high-energy supply in the form of cosmic rays or high energy photons. Very few studies have been devoted to the chemistry of HCN in the gas phase or at the gas/solid interphase, although they represent the more common scenarios in the outer space. In this paper we report about the reactivity of highly pure HCN in the 150-300 K range at the surface of amorphous and crystalline Mg2SiO4 (forsterite olivine), i.e. of solids among the constituents of the core of cosmic dust particles, comets, and meteorites. Amorphous silica and MgO were also studied as model representatives of Mg2SiO4 structural building blocks. IR spectroscopic results and the HR-MS analysis of the reaction products revealed Mg2+O2- acid/base pairs at the surface of Mg2SiO4 and MgO to be key in promoting the formation of HCN oligomers along with imidazole and purine compounds, already under very mild temperature and HCN pressure conditions, i.e. in the absence of external energetic triggers. Products include adenine nucleobase, a result which supports the hypothesis that prebiotic molecular building blocks can be easily formed through surface catalytic processes in the absence of high-energy supply.

Evaluation of Fenton and modified Fenton oxidation coupled with membrane distillation for produced water treatment: Benefits, challenges, and effluent toxicity.

Membrane distillation is a promising technology to desalinate hypersaline produced waters. However, the organic content can foul and wet the membrane, while some fractions may pass into the distillate and impair its quality. In this study, the applicability of the traditional Fenton process was investigated and preliminarily optimized as a pre-treatment of a synthetic hypersaline produced water for the following step of membrane distillation. The Fenton process was also compared to a modified Fenton system, whereby safe iron ligands, i.e., ethylenediamine-N,N'-disuccinate and citrate, were used to overcome practical limitations of the traditional reaction. The oxidation pre-treatments achieved up to 55% removal of the dissolved organic carbon and almost complete degradation of the low molecular weight toxic organic contaminants. The pre-treatment steps did not improve the productivity of the membrane distillation process, but they allowed for obtaining a final effluent with significantly higher quality in terms of organic content and reduced Vibrio fischeri inhibition, with half maximal effective concentration (EC50) values up to 25 times those measured for the raw produced water. The addition of iron ligands during the oxidation step simplified the process, but resulted in an effluent of slightly lower quality in terms of toxicity compared to the use of traditional Fenton.

Enzyme Immunoassay for Measuring Aflatoxin B1 in Legal Cannabis.

The diffusion of the legalization of cannabis for recreational, medicinal and nutraceutical uses requires the development of adequate analytical methods to assure the safety and security of such products. In particular, aflatoxins are considered to pose a major risk for the health of cannabis consumers. Among analytical methods that allows for adequate monitoring of food safety, immunoassays play a major role thanks to their cost-effectiveness, high-throughput capacity, simplicity and limited requirement for equipment and skilled operators. Therefore, a rapid and sensitive enzyme immunoassay has been adapted to measure the most hazardous aflatoxin B1 in cannabis products. The assay was acceptably accurate (recovery rate: 78-136%), reproducible (intra- and inter-assay means coefficients of variation 11.8% and 13.8%, respectively), and sensitive (limit of detection and range of quantification: 0.35 ng mL-1 and 0.4-2 ng mL-1, respectively corresponding to 7 ng g-1 and 8-40 ng g-1 ng g-1 in the plant) and provided results which agreed with a HPLC-MS/MS method for the direct analysis of aflatoxin B1 in cannabis inflorescence and leaves. In addition, the carcinogenic aflatoxin B1 was detected in 50% of the cannabis products analyzed (14 samples collected from small retails) at levels exceeding those admitted by the European Union in commodities intended for direct human consumption, thus envisaging the need for effective surveillance of aflatoxin contamination in legal cannabis.

Natural iron ligands promote a metal-based oxidation mechanism for the Fenton reaction in water environments.

The Fenton reaction is an effective advanced oxidation process occurring in nature and applied in engineering processes toward the degradation of harmful substances, including contaminants of emerging concern. The traditional Fenton application can be remarkably improved by using iron complexes with organic ligands, which allow for the degradation of contaminants at near-neutral pH and for the reduction of sludge production. This work discusses the mechanisms involved both in the classic Fenton process and in the presence of ligands that coordinate iron. Cyclohexane was selected as mechanistic probe, by following the formation of the relevant products, namely, cyclohexanol (A) and cyclohexanone (K). As expected, the classic Fenton process was associated with an A/K ratio of approximately 1, evidence of a dominant free radical behavior. Significantly, the presence of widely common natural and synthetic carboxyl ligands selectively produced mostly the alcoholic species in the first oxidation step. A ferryl-based mechanism was thus preferred when iron complexes were formed. Common iron ligands are here proven to direct the reaction pathway towards a selective metal-based catalysis. Such a system may be more easily engineered than a free radical-based one to safely remove hazardous contaminants from water and minimize the production of harmful intermediates.

The role of direct photolysis in the photodegradation of the herbicide bentazone in natural surface waters.

The photochemical fate of the herbicide bentazone was assessed by lab experiments and modeling tools. Experimental and modeling results showed that bentazone is mainly photodegraded by direct photolysis in natural water samples, even in the presence of dissolved organic matter (DOM) that can act as light-screening agent, photosensitizer and scavenger of reactive species. Even when it was dissolved in natural water samples containing different DOM amounts, the phototransformation kinetics of bentazone was unchanged compared to irradiation runs in ultrapure water. This finding suggests that the DOM and the other components of our samples did not affect the direct photolysis of bentazone by light-absorption competition, at least at the experimental optical path lengths, and did not induce significant indirect photodegradation by producing reactive transient species. Photochemical modeling in a lake-water photoreactivity scenario corroborated the observed experimental results, showing the predominant role of direct photolysis in the overall (direct + indirect) photodegradation of bentazone at different water depths and DOM contents. However, the model predicted a minor but non-negligible contribution of indirect photochemistry (i.e., reactions triggered by HO•, CO3•- and 3CDOM*) to the herbicide degradation. This contribution (especially by 3CDOM*) could become crucial in deep and DOM-rich water bodies. Finally, several photoproducts formed by direct photolysis and HO•-induced photodegradation were identified, which should not be particularly toxic for aquatic organisms and Vibrio fischeri bacteria.

Novel "Matrix-Corrected Calibration" study for the detection of polyunsaturated fatty acids (PUFAs) in plasma and erythrocytes by means of a gas chromatography-mass spectrometry approach optimized to follow up long-term parental patients.

An accurate and specific gas chromatography-mass spectrometry (GC-MS) method was optimized to quantify specific polyunsaturated fatty acids (PUFAs) in plasma and in erythrocyte membranes for clinical purposes. The developed and fully-validated method showed optimal linearity in addition to adequate results in terms of accuracy, intra-day and inter-day precision. By adopting the Matrix-Corrected Calibration approach on all the biological matrices tested, both the constant and the proportional errors of the developed analytical methodology were considered to assure that the method was not affected by matrix bias. Moreover, a pilot study involving patients in parental nutrition with two different compositions of the administered fat emulsion was performed. The comparison of results obtained in these patients with a group of healthy subjects (i.e. control population) showed significant differences in the collected values of PUFAs in both plasma and erythrocyte membranes, thus providing evidence that the described GC-MS method could be employed as a simple tool for fast and accurate PUFAs analysis aimed at optimizing parenteral nutrition protocols.

An experimental methodology to measure the reaction rate constants of processes sensitised by the triplet state of 4-carboxybenzophenone as a proxy of the triplet states of chromophoric dissolved organic matter, under steady-state irradiation conditions.

By a combination of transient absorption spectroscopy and steady-state irradiation experiments, we investigated the transformation of phenol and furfuryl alcohol (FFA) sensitised by irradiated 4-carboxybenzophenone (CBBP). The latter is a reasonable proxy molecule to assess the reactivity of the excited triplet states of the chromophoric dissolved organic matter that occurs in natural waters. The main reactive species for the transformation of both phenol and FFA was the CBBP triplet state, despite the fact that FFA is a commonly used probe for 1O2. In the case of FFA it was possible to develop a simple kinetic model that fitted well the experimental data obtained by steady-state irradiation, in a wide range of FFA concentration values. In the case of phenol the model was made much more complex by the likely occurrence of back reactions between radical species (e.g., phenoxyl and superoxide). This problem can be tackled by considering only the experimental data at low phenol concentration, where the degradation rate increases linearly with concentration. We do not recommend the use of 1O2 scavengers/quenchers such as sodium azide to elucidate CBBP photoreaction pathways, because the azide provides misleading results by also acting as a triplet-state quencher. Based on the experimental data, we propose a methodology for the measurement of the CBBP triplet-sensitisation rate constants from steady-state irradiation experiments, allowing for a better assessment of the triplet-sensitised degradation of emerging contaminants.

Development and validation of an HPLC-MS/MS method for the detection of ketamine in Calliphora vomitoria (L.) (Diptera: Calliphoridae).

Entomotoxicology is a branch of forensic entomology that studies the detection of drugs or other toxic substances from insects developing on the decomposing tissues of a human corpse or animal carcass. Entomotoxicology also investigates the effects of these substances on insect development, survival and morphology to provide an estimation of the minimum time since death. Ketamine is a medication mainly used for starting and maintaining anesthesia. In recent years ketamine has also been used as a recreational drug, and occasionally as a sedating drug to facilitate sexual assault. In both activities, it has resulted in several deaths. Furthermore, ketamine has been also implicated in suspicious deaths of animals. The present research describes for the first time the development and validation of an analytical method suited to detect ketamine in larvae, pupae, empty puparia, and adults of Calliphora vomitoria L. (Diptera: Calliphoridae), using liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). This research also considers the effects of ketamine on the survival, developmental rate and morphology (length and width of larvae and pupae) of C. vomitoria. The larvae were reared on liver substrates homogeneously spiked with ketamine concentrations consistent with those found in humans after recreational use (300 ng/mg) or allegedly indicated as capable of causing death in either humans or animals (600 ng/mg). The results demonstrated that (a) HPLC-MS/MS method is applicable to ketamine detection in C. vomitoria immatures, not adults; (b) the presence of ketamine at either concentration in the food substrate significantly delays the developmental time to pupal and adult instar; (d) the survival of C. vomitoria is negatively affected by the presence of ketamine in the substrate; (e) the length and width of larvae and pupae exposed to either ketamine concentration were significantly larger than the control samples.

The effect of antifreeze (ethylene glycol) on the survival and the life cycle of two species of necrophagous blowflies (Diptera: Calliphoridae).

Entomotoxicology involves the analysis of the presence and the effects of toxicological substances in necrophagous insects. Results obtained by entomotoxicological studies may assist in the investigation of both the causes and the time of death of humans and animals. Ethylene glycol (EG) is easy to purchase, sweet and extremely toxic. It may be consumed accidentally or purposefully, in an attempt to cause death for suicidal or homicidal intent. Several cases report fatalities of humans and animals. The present study is the first to examine the effects of EG on the survival, developmental rate and morphology of two blowfly species, (Diptera: Calliphoridae) typically found on corpses and carcasses: Lucilia sericata (Meigen) and L. cuprina (Wiedemann). Both species were reared on substrates (beef liver) spiked with three different concentrations of EG that could cause death in either a human or cat: 1/2LD50 (T1), LD50 (T2), 2LD50 (T3), in addition to a control treatment (C) with no EG. Results of this research show that: a) both species are unable to survive if reared on a food substrate spiked with the highest concentration of EG (T3), while lower and medium concentrations (T1, T2) affect, but not prevent, the survival and the completion of the life cycle of such species; b) adults of L. sericata eclose only in C and T1, while adults of L. cuprina in both C, T1, T2; however, c) the developmental time of both species reared in T1 and T2 is statistically slower than the control; d) the body length of the immatures of both of the species reared in T1 and T2 is statistically smaller than the control.

Does the Abiotic Formation of Oligopeptides on TiO2 Nanoparticles Require Special Catalytic Sites? Apparently Not.

The oligomerization of non-activated amino acids catalyzed by nanostrucrured mineral oxide surfaces holds promises as a sustainable route for the industrial production of polypeptides. To analyze the influence of the surface type on the catalytic process, we performed, via a mild Chemical Vapor Deposition approach, the oligomerization of Glycine on two samples of TiO2 nanoparticles characterized by different relative amounts of defective surface terminations. Based on infrared spectroscopy and mass spectrometry data, we show herein that the formation of peptide bonds on titania nanoparticles does not require highly energetic surface terminations, but can occur also on the most abundant and thermodynamically most stable {101} facets of nanosized anatase.

Development and Validation of a Method for the Detection of α- and ß-Endosulfan (Organochlorine Insecticide) in Calliphora vomitoria (Diptera: Calliphoridae).

Entomotoxicology studies employ analytical methods and instrumentation to detect chemical substances in carrion insects feeding from the decomposing tissues. The identification of such chemicals may determine the cause of death and may be used for the estimation of the minimum time since death. To date, the main focus of entomotoxicological studies has been the detection of drugs, whereas little information concerns the effects of pesticides on blowflies. Pesticides are generally freely available and more affordable than drugs but they can also be a home hazard and an accessible candidate poison at a crime scene. A QuEChERS extraction method followed by Gas chromatography-mass spectrometry (GC-MS) analysis was developed for the detection of α- and ß-endosulfan (organochlorine insecticide and acaricide) in Calliphora vomitoria L. (Diptera: Calliphoridae) and validated. Furthermore, the effects of endosulfan on the morphology, development time and survival of the immature blowflies were investigated. Larvae were reared on liver substrates homogeneously spiked with aliquots of endosulfan corresponding to the concentrations found in body tissues of humans and animals involved in endosulfan poisoning. Results demonstrated that the combination of QuEChERS extraction and GC-MS provide an adequate methods to detect both α- and ß-endosulfan in blowfly immatures. Furthermore, the presence of α- and ß-endosulfan in the food source 1) prevented C. vomitoria immatures reaching the pupal instar and, therefore, the adult instar at high concentrations, 2) did not affect the developmental time of blowflies at low concentrations 3) affected the size of immatures only at high concentrations, resulting in significantly smaller larvae.

"One-pot" ethyl chloroformate derivatization and liquid-liquid extraction of reduced glutathione in erythrocyte and its quantitative GC-MS analysis.

A simple "one-pot" derivatization and liquid-liquid extraction (LLE) procedure was developed for GC-MS analysis of reduced glutathione (GSH) analysis in erythrocytes. The metabolite was extracted by 5% (w/v) TCA, the supernatant treated with ECF and ethanol-pyridine media, the derivative separated and detected by gas chromatography-mass spectrometry using a short non-polar capillary GC column at a high column-head pressure. Total analysis time was 11min. The process was optimized by a Design of Experiment. The method was validated showing a good linearity over the 25.4-813.4µM concentration range, providing satisfactory results in terms of intra-day and inter-day precision as well as an optimal accuracy. The new method was evaluated in a pilot study involving patients with severe protein malnutrition. Comparison of this group with a group of healthy subjects revealed significantly lower GSH concentrations in erythrocytes in the former, thus proving that the described GC-MS method could be employed for fast and simple GSH analysis in clinical studies.

Chromium, nickel, and cobalt in cosmetic matrices: an integrated bioanalytical characterization through total content, bioaccessibility, and Cr(III)/Cr(VI) speciation.

The presence of certain metals naturally contained inside raw materials (e.g., pigments) used to produce cosmetics for make-up may represent a serious concern for the final quality and safety of the product. The knowledge of the total concentration of metals is not sufficient to predict their reactivity and their toxicological profile. For these reasons, we set up a comprehensive approach to characterize the content of Co, Cr, and Ni in two raw materials for cosmetic production, a black iron oxide and a pearly pigment, and in a finished product, pearly powder eye shadow. Namely, besides the total metal concentrations, the speciation of chromium and the bioaccessibility of the three metals were assessed. Since no standard method is so far available for hexavalent chromium extraction from cosmetic samples, three approaches were compared (EPA 3060A method, IRSA 16 method, and a Na3PO4 extraction). Results show that Na3PO4 extraction is the most selective one. Cr(VI) was undetectable in black iron oxide and present at very low concentrations (about 0.3 mg/kg) in pearly pigment and in the pearly powder eye shadow samples. The extracted Cr(VI) concentrations are not related to the total Cr content in the samples. Bioaccessibility studies were performed by in vitro extractions with synthetic lacrimal fluids and sweat. Despite the wide range of metal concentrations in the samples, the amounts of bioaccessible elements were undetectable or very low (less than 0.4 mg/kg), thus suggesting that metals in the three samples are present in inert forms. Graphical abstract The possible leaching of metals from cosmetics to biological fluids. Spectroscopic and chromatographic techniques provide complementary information for an integrated bioanalytical approach to risk characterization.

Mass spectrometric fragmentation and photocatalytic transformation of nicotine and cotinine.

RATIONALE: Nicotine and cotinine are, respectively, alkaloids produced mainly by the Solanaceae plant family, especially tobacco, and its most important human metabolite. These compounds are frequently found as contaminants in wastewater or landfill samples and they could be used to evaluate pollution by tobacco use. The aim of this study is to improve the knowledge about possible transformation pathways of nicotine and cotinine. This would help the identification of degradants by using HPLC coupled with a high resolving power mass analyzer (LTQ-Orbitrap). In addition, we evaluated toxicity on bioluminescent photobacteria to indicate possible relationships between the formation of transformation products and their toxic effects. METHODS: The transformation of nicotine and cotinine and the formation of intermediate products were evaluated adopting titanium dioxide as photocatalyst. The structural identification of photocatalytic transformation products of these two alkaloids was based on LC/multistage MS experiments. High-resolution MS allowed the elemental composition of these products to be hypothesized. The evolution of toxicity as a function of the irradiation time was also studied using a bioluminescent photobacterium (Vibrio fischeri) test. RESULTS: Several products were formed and characterized using HPLC/HRMSn . The main photocatalytic pathways involving nicotine and cotinine appear to be hydroxylation, demethylation and oxidation. Nine degradants were formed from nicotine, including cotinine. Seven degradants were generated from cotinine. There is no transformation product in common between the two studied molecules. CONCLUSIONS: The study of photocatalytic degradation allowed us to partially simulate human metabolism and the environmental transformation of the bioactive alkaloid nicotine. We searched for some of the identified transformation products in river water and landfill percolate by solid-phase extraction and HPLC/HRMS and eventually their presence was confirmed. These new findings could be of interest in further metabolism and environmental pollution studies. Copyright © 2016 John Wiley & Sons, Ltd.

Assessing the phototransformation of diclofenac, clofibric acid and naproxen in surface waters: Model predictions and comparison with field data.

Phototransformation is important for the fate in surface waters of the pharmaceuticals diclofenac (DIC) and naproxen (NAP) and for clofibric acid (CLO), a metabolite of the drug clofibrate. The goal of this paper is to provide an overview of the prevailing photochemical processes, which these compounds undergo in the different conditions found in freshwater environments. The modelled photochemical half-life times of NAP and DIC range from a few days to some months, depending on water conditions (chemistry and depth) and on the season. The model indicates that direct photolysis is the dominant degradation pathway of DIC and NAP in sunlit surface waters, and potentially toxic cyclic amides were detected as intermediates of DIC direct phototransformation. With modelled half-life times in the month-year range, CLO is predicted to be more photostable than DIC or NAP and to be degraded mainly by reaction with the •OH radical and with the triplet states of chromophoric dissolved organic matter (3CDOM*). The CLO intermediates arising from these processes and detected in this study (hydroquinone and 4-chlorophenol) are, respectively, a chronic toxicant to aquatic organisms and a possible carcinogen for humans. Hydroquinone is formed with only ∼5% yield upon CLO triplet-sensitised transformation, but it is highly toxic for algae and crustaceans. In contrast, the formation yield of 4-chlorophenol reaches ∼50% upon triplet sensitisation and ∼10% by ·OH reaction. The comparison of model predictions with field data from a previous study yielded a very good agreement in the case of DIC and, when using 4-carboxybenzophenone as proxy for triplet sensitisation by CDOM, a good agreement was found for CLO as well. In the case of NAP, the comparison with field data suggests that its direct photolysis quantum yield approaches or even falls below the lower range of literature values.

Development and validation of a GC-MS method for nicotine detection in Calliphora vomitoria (L.) (Diptera: Calliphoridae).

Entomotoxicology is the application of toxicological methods and analytical procedures on necrophagous insects feeding on decomposing tissues to detect drugs and other chemical components, and their mechanisms affecting insect development and morphology and modifying the methodology for estimation of minimum time since death. Nicotine is a readily available potent poison. Because of its criminal use, a gas chromatography-mass spectrometry (GC-MS) method for the detection of nicotine in Calliphora vomitoria L. (Diptera: Calliphoridae) was developed and validated. Furthermore, the effect of nicotine on the development, growth rate, and survival of this blowfly was studied. Larvae were reared on liver substrates homogeneously spiked with measured amounts of nicotine (2, 4, and 6 ng/mg) based on concentrations that are lethal to humans. The results demonstrated that (a) the GC-MS method can detect both nicotine and its metabolite cotinine in immature C. vomitoria; (b) the presence of nicotine in the aforementioned three concentrations in food substrates did not modify the developmental time of C. vomitoria; (c) during the pupation period, larvae exposed to nicotine died depending on the concentration of nicotine in the substrate; and (d) the resultant lengths of larvae and pupae exposed to 4 and 6 ng/mg concentrations of nicotine were significantly shorter than those of the control.

Urban air and tobacco smoke as conditions that increase the risk of oxidative stress and respiratory response in youth.

BACKGROUND: Air pollution and tobacco smoke can induce negative effects on the human health and often leads to the formation of oxidative stress. OBJECTIVE: The purpose of this study was to clarify the role of the urbanization degree and of passive exposure to tobacco smoke in the formation of oxidative stress. Thus, a group of non-smoking adolescents was recruited among those who live and attend school in areas with three different population densities. To each subject a spot of urine was collected to quantify 15-F2t isoprostane as a marker of oxidative stress and cotinine as a marker of passive exposure to tobacco smoke. Furthermore, respiratory functionality was also measured. RESULTS: Multiple linear regression analysis results showed a direct correlation (p<0.0001) of 15-F2t isoprostane with both the urbanization and passive smoke. Lung function parameters proved significantly lower for the subjects living in the most populous city of Torino. CONCLUSION: This remarks the negative effect that urbanization has on the respiratory conditions. Lastly, lung functionality presented a low inverse correlation with 15-F2t isoprostane, suggesting an independent mechanism than that of the urban factor.