A simple and automated sample preparation system for subsequent halogens determination: Combustion followed by pyrohydrolysis.

A simple and automated system based on combustion followed by a pyrohydrolysis reaction was proposed for further halogens determination. This system was applied for digestion of soils containing high (90%) and also low (10%) organic matter content for further halogens determination. The following parameters were evaluated: sample mass, use of microcrystalline cellulose and heating time. For analytes absorption, a diluted alkaline solution (6 mL of 25 mmol L-1 NH4OH) was used in all experiments. Up to 400 mg of soil with high organic matter content and 100 mg of soil with low organic matter content (mixed with 400 mg of cellulose) could be completely digested using the proposed system. Quantitative results for all halogens were obtained using less than 12 min of sample preparation step (about 1.8 min for sample combustion and 10 min for pyrohydrolysis). The accuracy was evaluated using a certified reference material of coal and spiked samples. No statistical difference was observed between the certified values and results obtained by the proposed method. Additionally, the recoveries obtained using spiked samples were in the range of 98-103% with relative standard deviation values lower than 5%. The limits of quantification obtained for F, Cl, Br and I for soil with high (400 mg of soil) and low (100 mg of soil) organic matter were in the range of 0.01-2 µg g-1 and 0.07-59 µg g-1, respectively. The proposed system was considered as a simple and suitable alternative for soils digestion for further halogens determination by ion chromatography and inductively coupled plasma mass spectrometry techniques.

Could hypoxia acclimation cause morphological changes and protect against Mn-induced oxidative injuries in silver catfish (Rhamdia quelen) even after reoxygenation?

Exposure to hypoxia has shown beneficial adjustments in different species, including silver catfish (Rhamdia quelen), especially in situations of aquatic contamination with pollutants such as manganese (Mn). Considering that hypoxia is seasonal in the natural aquatic environment, we decided to assess whether these adaptive mechanisms could be maintained when reoxygenation is established. Silver catfish acclimated to moderate hypoxia (∼3 mg L-1, 41% O2 saturation) for 10 days and subsequently exposed to Mn (∼8.1 mg L-1) for additional 10 days displayed lower (47%) Mn accumulation in the gills, and it was maintained (62.6%) after reoxygenation, in comparison to normoxia. Oxidative status in the gills allowed us to observe increased reactive species (RS) generation and protein carbonyl (PC) level together with decreased mitochondrial viability induced by Mn under normoxia. Inversely, while hypoxia per se was beneficial on RS generation and PC level, this acclimation was able to minimize Mn toxicity, as observed by the minor increase of RS generation and the minor reduction of mitochondrial viability, together with decreased PC level. Interestingly, after reoxygenation, part of the protective influences observed during hypoxia against Mn toxicity were maintained, as observed through a lower level of PC and higher mitochondrial viability in relation to the group exposed to Mn under normoxia. Only groups exposed to Mn under hypoxia showed increased activity of both catalase (CAT) and Na+/K+-ATPase in the gills, but, while CAT activity remained increased after reoxygenation, Na+/K+-ATPase activity was decreased by Mn, regardless of the oxygen level. Based on these outcomes, it is possible to propose that environment events of moderate hypoxia are able to generate rearrangements in the gills of silver catfish exposed to Mn, whose influence persists after water reoxygenation. These responses may be related to the adaptive development, reducing Mn toxicity to silver catfish. Moderate hypoxia generates rearrangements in the gills of Silver catfish, exerting beneficial and persistent protection against Mn toxicity.

Estimation of RF energy absorbed in the brain from mobile phones in the Interphone Study.

OBJECTIVES: The objective of this study was to develop an estimate of a radio frequency (RF) dose as the amount of mobile phone RF energy absorbed at the location of a brain tumour, for use in the Interphone Epidemiological Study. METHODS: We systematically evaluated and quantified all the main parameters thought to influence the amount of specific RF energy absorbed in the brain from mobile telephone use. For this, we identified the likely important determinants of RF specific energy absorption rate during protocol and questionnaire design, we collected information from study subjects, network operators and laboratories involved in specific energy absorption rate measurements and we studied potential modifiers of phone output through the use of software-modified phones. Data collected were analysed to assess the relative importance of the different factors, leading to the development of an algorithm to evaluate the total cumulative specific RF energy (in joules per kilogram), or dose, absorbed at a particular location in the brain. This algorithm was applied to Interphone Study subjects in five countries. RESULTS: The main determinants of total cumulative specific RF energy from mobile phones were communication system and frequency band, location in the brain and amount and duration of mobile phone use. Though there was substantial agreement between categorisation of subjects by cumulative specific RF energy and cumulative call time, misclassification was non-negligible, particularly at higher frequency bands. Factors such as adaptive power control (except in Code Division Multiple Access networks), discontinuous transmission and conditions of phone use were found to have a relatively minor influence on total cumulative specific RF energy. CONCLUSIONS: While amount and duration of use are important determinants of RF dose in the brain, their impact can be substantially modified by communication system, frequency band and location in the brain. It is important to take these into account in analyses of risk of brain tumours from RF exposure from mobile phones.

["An Italian Court recognizes the occupational origin of a trigeminal neuroma in a mobile telephone user: a case-study of the complex relationships between science and laws"]. / Una Corte italiana riconosce l'origine professionale di un neurinoma del trigemino in un utilizzatore di telefoni mobili: un esempio concreto dei complessi rapporti tra scienza e diritto.

BACKGROUND: Scientific knowledge is essential for the resolution of disputes in law and administrative applications (such as toxic tort litigation and workers' compensation) and provides essential input for public policy decisions. There are no socially agreed-upon rules for the application of this knowledge except in the law. On a practical level, the legal system lacks the ability to assess the validity of scientific knowledge that can be used as evidence and therefore relies heavily on expert opinion. A key issue is how to ensure that professionals in any field provide judges with sound advice, based on relevant and reliable scientific evidence. The search for solutions to this problem seems particularly urgent in Italy, a country where a number of unprecedented verdicts of guilt have been pronounced in trials involving personal injuries from exposure to electromagnetic fields. OBJECTIVES AND METHODS: An Italian Court has recently recognized the occupational origin of a trigeminal neuroma in a mobile telephone user, and ordered the Italian Workers' Compensation Authority (INAIL) to award the applicant compensation for a high degree (80%) of permanent disability. We describe and discuss the salient aspects of this sentence as a case-study in the framework of the use (and misuse) of scientific evidence in toxic-tort litigations. RESULTS: Based on the motivations of the verdict, it appears that the judge relied on seriously flawed expert testimonies. The "experts" who served in this particular trial were clearly inexperienced in forensic epidemiology in general, as well as in the topic at hand. Selective overviews of scientific evidence concerning cancer risks from mobile phone use were provided, along with misleading interpretations of findings from relevant epidemiologic studies (including the dismissal of the Interphone study results on the grounds of purported bias resulting from industry funding). The necessary requirements to proceed to causal inferences at individual level were not taken into account and inappropriate methods to derive estimates of personal risk were used. CONCLUSIONS: A comprehensive strategy to improve the quality of expert witness testimonies in legal proceedings and promote just and equitable verdicts is urgently needed in Italy. Contrary to other countries, such as the United States or the United Kingdom, legal standards for expert testimony, such as preliminary assessment of scientific evidence admissibility and qualification requirements for professionals acting as experts in the courtroom, are lacking in our country. In this and similar contexts, recommendations issued by professional associations (including EBEA and BEMS) could play a role of paramount importance. As examples, we refer to the guidelines recently endorsed by the UK General Medical Council and the American Academy of Pediatrics.

Determinants of mobile phone output power in a multinational study: implications for exposure assessment.

OBJECTIVES: The output power of a mobile phone is directly related to its radiofrequency (RF) electromagnetic field strength, and may theoretically vary substantially in different networks and phone use circumstances due to power control technologies. To improve indices of RF exposure for epidemiological studies, we assessed determinants of mobile phone output power in a multinational study. METHODS: More than 500 volunteers in 12 countries used Global System for Mobile communications software-modified phones (GSM SMPs) for approximately 1 month each. The SMPs recorded date, time, and duration of each call, and the frequency band and output power at fixed sampling intervals throughout each call. Questionnaires provided information on the typical circumstances of an individual's phone use. Linear regression models were used to analyse the influence of possible explanatory variables on the average output power and the percentage call time at maximum power for each call. RESULTS: Measurements of over 60,000 phone calls showed that the average output power was approximately 50% of the maximum, and that output power varied by a factor of up to 2 to 3 between study centres and network operators. Maximum power was used during a considerable proportion of call time (39% on average). Output power decreased with increasing call duration, but showed little variation in relation to reported frequency of use while in a moving vehicle or inside buildings. Higher output powers for rural compared with urban use of the SMP were observed principally in Sweden where the study covered very sparsely populated areas. CONCLUSIONS: Average power levels are substantially higher than the minimum levels theoretically achievable in GSM networks. Exposure indices could be improved by accounting for average power levels of different telecommunications systems. There appears to be little value in gathering information on circumstances of phone use other than use in very sparsely populated regions.

A 700 MHz 1H-NMR study reveals apoptosis-like behavior in human K562 erythroleukemic cells exposed to a 50 Hz sinusoidal magnetic field.

PURPOSE: To study cell damage and possible apoptosis in K562 human erythroleukemic cells exposed for 2 h to an extremely low frequency (ELF) 50 Hz sinusoidal magnetic field with a magnetic induction of either 1 or 5 mT using high resolution proton nuclear magnetic resonance (1H-NMR) spectroscopy. MATERIALS AND METHODS: One-dimensional 1H-NMR spectra were obtained on whole K562 cells and perchloric acid extracts of these cells. In addition, two-dimensional 1H-NMR spectra were also acquired. Cell damage was examined by lactate dehydrogenase release and changes in cell growth were monitored by growth curve analyses, bromodeoxyuridine incorporation and Ki67 antigen localization. Cell death (necrosis and apoptosis) were also studied by using the chromatin dye Hoechst 33258. RESULTS: The variations in numerous metabolites observed with 1H-NMR reveal apoptosis-like behavior in response of K562 cells to ELF fields. CONCLUSION: 1H-NMR can be extremely useful in studying the effects of ELF fields on cells. In particular, the variations in metabolites which suggest apoptosis-like behavior occur when the cells are not identifiable as apoptotic by more traditional techniques.

Output power levels from mobile phones in different geographical areas; implications for exposure assessment.

BACKGROUND: The power level used by the mobile phone is one of the most important factors determining the intensity of the radiofrequency exposure during a call. Mobile phone calls made in areas where base stations are densely situated (normally urban areas) should theoretically on average use lower output power levels than mobile phone calls made in areas with larger distances between base stations (rural areas). AIMS: To analyse the distribution of power levels from mobile phones in four geographical areas with different population densities. METHODS: The output power for all mobile phone calls managed by the GSM operator Telia Mobile was recorded during one week in four defined areas (rural, small urban, suburban, and city area) in Sweden. The recording included output power for the 900 MHz and the 1800 MHz frequency band. RESULTS: In the rural area, the highest power level was used about 50% of the time, while the lowest power was used only 3% of the time. The corresponding numbers for the city area were approximately 25% and 22%. The output power distribution in all defined urban areas was similar. CONCLUSION: In rural areas where base stations are sparse, the output power level used by mobile phones are on average considerably higher than in more densely populated areas. A quantitative assessment of individual exposure to radiofrequency fields is important for epidemiological studies of possible health effects for many reasons. Degree of urbanisation may be an important parameter to consider in the assessment of radiofrequency exposure from mobile phone use.

Occurrence of Podosphaera xanthii Race 2 on Cucumis melo in Brazil.

Powdery mildew is an important disease of melons (Cucumis melo L.) cultivated in greenhouses in Brazil. Currently, there are 5 races of Podosphaera xanthii (formerly known as Sphaerotheca fuliginea) and 2 races of Golovinomyces cichoracearum (formerly known as Erysiphe cichoracearum) described on melons worldwide, but only race 1 of P. xanthii has been reported in Brazil (1). However, typical whitish powdery fungal growth was observed on an experimental hybrid yellow melon resistant to race 1 of P. xanthii during the summer of 2000 in a greenhouse in Bragança Paulista, State of São Paulo. Conidia collected from diseased leaves were spread onto 0.5% water agar medium and maintained at 22°C for 24 h with 12 h of light and 12 h of darkness. Most of the germinated conidia displayed fibrosin inclusion bodies when observed in a solution of 3% potassium hydroxide (KOH), and approximately 1 of 50 also displayed forked germ tubes. These features allowed us to identify P. xanthii as the causal agent. Conidia raised on the susceptible yellow melon 'Amarelo CAC' were used to inoculate cotyledons of the differential melon lines (2) 'Hale's Best Jumbo' (susceptible to races 1, 2, and 3 of P. xanthii), 'PMR-45' (resistant to race 1 and susceptible to races 2 and 3), and 'PMR-6' (resistant to races 1 and 2 and susceptible to race 3). Inoculations were performed on 10 plants of each differential line and replicated four times. The presence or absence of symptoms was evaluated 18 days after inoculation. 'Hale's Best Jumbo' and 'PMR-45' were rated as susceptible while 'PMR-6' was rated as resistant, thus indicating the presence of race 2 of P. xanthii in Brazil. During field surveys from 2001 to 2003, this race was found on squash (Cucurbita moschata), summer squash (C. pepo), and melons in São Paulo. References: (1) F. J. B. Reifschneider et al. Plant Dis. 69:1069, 1985. (2) C. E. Thomas et al. Cucurbit Genet. Coop. 7:126, 1984.

Perception of risks from electromagnetic fields: lessons for the future.

Technologies based on extremely highfrequency electromagnetic fields, inparticular in the terahertz region, arequite recent and new to the public. While anumber of advantages have been shown,especially in the biomedical area,biological effects and possible healthimplications have not been fullyinvestigated. The experience gained withelectromagnetic fields of lowerfrequencies, from ELF to microwaves,suggests that innovating technologies maycreate concern, or even fear, among thepublic for hypothetical health risks.Social research has shown that worries arerelated to the perception of risks by thepublic more than to their actual existence.Risk perception depends on several factors,many of which are relevant forelectromagnetic fields. They include lackof familiarity with the agent, difficultyin understanding interaction mechanisms,and uncertainty in scientific knowledge.Lessons learnt from the past lead torecommend that specific research onbiological effects of terahertz radiationbe started from the very beginning of thedevelopment of technological applicationsand that a continuous and effectivedialogue be established between thescientific community and the public.

Mortality of plastic-ware workers exposed to radiofrequencies.

The mortality experience of a cohort of Italian plastic-ware workers exposed to radiofrequency (RF)-electromagnetic fields generated by dielectric heat sealers was investigated. Follow-up extended from 1962 to 1992. The standardised mortality ratio (SMR) analysis was restricted to 481 women workers, representing 78% of the total person-years at risk. Mortality from malignant neoplasms was slightly elevated, and increased risks of leukemia and accidents were detected. The all-cancer SMR was higher among women employed in the sealing department, where exposure to RF occurred, than in the whole cohort. This study raises interest in a possible association between exposure to RF radiation and cancer risk. However, the study power was very small, and the possible confounding effects of exposure to solvents and vinyl chloride monomer (VCM) could not be ruled out. The hypothesis of an increased risk of cancer after radiofrequency exposure should be further explored by means of analytical studies characterised by adequate power and more accurate exposure assessment.

[The health risks of exposure to electromagnetic fields in work environments]. / Rischi per la salute da esposizione a campi elettromagnetici in ambienti di lavoro.

In the last few years the debate on possible health risks of electromagnetic fields has focused on specific sources, namely power lines and, more recently, base stations for cellular telephones. This has drastically diverted the attention of the research and prevention community towards residential exposures. On the other hand, the increasing number of technological process exploiting or generating electromagnetic fields requires greater attention to exposures at the workplace. The scope of research in this area is vast because of different emission characteristics of the sources, different interaction mechanisms at various frequencies, and different effects that have been identified or hypothesized. The paper presents an overview of health problems involved in exposure to electromagnetic fields at the workplace. Different frequency ranges and related sources are considered separately. In particular, the different levels of knowledge are noted and areas requiring further research are identified.

Human natural killer cytotoxic activity is not affected by in vitro exposure to 50-Hz sinusoidal magnetic fields.

Epidemiological studies have suggested, but not demonstrated, a role of exposure to 50/60-Hz magnetic fields in increasing cancer risk in man (workers and the general population). A possible target of magnetic fields is the immune system. In particular, it is known that an important defence against cancer is represented by natural killer (NK) cells capable of killing cancer cell targets. To test this hypothesis, human NK cells, stimulated or not with phytohaemagglutinin or interleukin 2, were exposed to 50-Hz sinusoidal magnetic fields before or during the cytotoxicity test, and then mixed with a variety of target cancer cell lines (Daudi, Raji, U937, H14, IGROV, SW626, K562, HL60). The experiments were performed in two laboratories (Rome and Modena) by means of two different exposure systems. The results of both laboratories suggest that 50-Hz sinusoidal magnetic fields with flux densities up to 10 mT do not affect the cytotoxic activity of human NK cells.

[Laparoscopic cholecystectomy: evaluation of intraoperative complications with respect to 2 different kinds of anesthesia]. / Colecistectomia laparoscopica: stima di alcune complicanze perioperatorie in rapporto a due differenti metodiche di anestesia.

Two anaesthetic managements for elective laparoscopic cholecystectomy were compared in 64 patients in order to investigate some perioperative complications: 1) bowel distension during surgery. 2) recovery from anaesthesia. 3) post-surgery incidence of emesis and pain. In addition, the quality of postoperative peristalsis as well as the time of dimissal were recorded. Group I (n = 30) was treated with NLA in N2O-O2 and Group II (n = 34) received propofol plus fentanyl in air-O2. Bowel distension, evaluated by surgeon at 15 min intervals throughout the operation was similar in both the groups as well as postoperative peristalsis recuperation. During the first 12 hours after laparoscopy no differences were found at any times of observation in the incidence or severity of emesis and pain between the two different anaesthesia patients. In subjects which were given propofol the psychomotor recovery was more rapid than after NLA, particularly during the first 6 hours after surgery. The patients were discharged between 36-48 hours following the operation independently from anaesthetic management. It is concluded that both the anaesthetic techniques provide similar intra/postoperative conditions, except the early recovery that is more rapid for the propofol patients. The overall frequency of emesis and pain was rather high in both the groups, suggesting a routine medication with analgesics and antiemetics.

[Very low frequency electric and magnetic fields and the immune system]. / Campi elettrici e magnetici a frequenze estremamente basse e sistema immunitario.

Recent residential and occupational epidemiological studies indicate a statistical association between 50-60 Hz magnetic field exposure and the risk of developing some kinds of tumors. Several experimental researches have been carried out in vitro and in vivo to verify the possibility that some cell functions may be influenced by ELF (Extremely Low Frequencies: 0-300 Hz) electric and magnetic fields. Such researchers are very important to assess if the statistical association indicated by the epidemiological studies is actually due to a cause-effect relationship between ELF electric and magnetic fields and carcinogenesis. In this review we describe the present state of the experimental research, focusing our attention on the effects of ELF fields on the immune system. We also describe some theoretical researches whose aim is to identify possible mechanisms of interaction between ELF fields and biological systems which may provide biological plausibility to the observed effects.

[Effects of betamethasone on neuromuscular blockade induced by vecuronium in continuous infusion]. / Effetti del betametasone sul blocco neuromuscolare indotto con vecuronium in infusione continua.

The aim of the study was to determine a possible interaction between a corticosteroid (betamethasone) and vecuronium, a nondepolarizing muscle relaxant. The authors studied 20 patients, ASA I-II, aged 20-54, both sexes, scheduled for abdominal surgery. Mechanomyographic and clinical evaluation by single twitch and TOF stimulation of the ulnar nerve at the wrist and measurement of the concomitant abductor pollicis muscle was applied. The onset time of vecuronium after a single bolus dose of 0.08 mg/kg, duration of action to 10% single twitch recovery, duration of continuous infusion of 0.4-0.5 micrograms/kg/min of vecuronium started at 10% single twitch recovery, and the effects of 0.1 mg/kg betamethasone administration 10 min after continuous infusion were evaluated. The recovery rate of vecuronium after stopping infusion at 10% recovery was also evaluated. Corticosteroids may interact with non-depolarizing muscle relaxants both in prejunctional and postjunctional acetylcholine receptors by several mechanisms of action.

Non-linear dependence of the dielectric properties of chick embryo myoblast membranes exposed to a sinusoidal 50 Hz magnetic field.

Primary chick embryo myoblasts can be a useful tool for studying the developmental events which accompany myoblast differentiation, particularly myoblast membrane fusion. To determine whether the electrical properties and/or fusion in these systems are affected by 50 Hz magnetic fields, chick embryo myoblast cultures were exposed to B-field intensities ranging from 1 to 10 mT. The electrical parameters of the myoblasts, i.e. membrane conductivity, membrane permittivity and the conductivity of the cell interior (cytosol) were determined by the analysis of conductivity dispersion data in the radio frequency range (10 kHz-100 MHz). Preliminary results indicate that the time of fusion (60 h) is not affected by these fields, but that the absolute values of the two membrane electrical parameters are affected. In particular, a B-field intensity-dependent decrease was observed. The maximum effect resulted after a 1 h exposure to a magnetic flux density of about 5 mT. The conductivity of the cytosol remained unchanged. These data seem to indicate that exposure to 50 Hz magnetic fields affects both static and dynamic membrane properties in primary chick embryo myoblasts.