Wireless phone use in childhood and adolescence and neuroepithelial brain tumours: Results from the international MOBI-Kids study

In recent decades, the possibility that use of mobile communicating devices, particularly wireless (mobile and cordless) phones, may increase brain tumour risk, has been a concern, particularly given the considerable increase in their use by young people. MOBI-Kids, a 14-country (Australia, Austria, Canada, France, Germany, Greece, India, Israel, Italy, Japan, Korea, the Netherlands, New Zealand, Spain) case-control study, was conducted to evaluate whether wireless phone use (and particularly resulting exposure to radiofrequency (RF) and extremely low frequency (ELF) electromagnetic fields (EMF)) increases risk of brain tumours in young people. Between 2010 and 2015, the study recruited 899 people with brain tumours aged 10 to 24 years old and 1,910 controls (operated for appendicitis) matched to the cases on date of diagnosis, study region and age. Participation rates were 72% for cases and 54% for controls. The mean ages of cases and controls were 16.5 and 16.6 years, respectively; 57% were males. The vast majority of study participants were wireless phones users, even in the youngest age group, and the study included substantial numbers of long-term (over 10 years) users: 22% overall, 51% in the 20-24-year-olds. Most tumours were of the neuroepithelial type (NBT; n = 671), mainly glioma. The odds ratios (OR) of NBT appeared to decrease with increasing time since start of use of wireless phones, cumulative number of calls and cumulative call time, particularly in the 15-19 years old age group. A decreasing trend in ORs was also observed with increasing estimated cumulative RF specific energy and ELF induced current density at the location of the tumour. Further analyses suggest that the large number of ORs below 1 in this study is unlikely to represent an unknown causal preventive effect of mobile phone exposure: they can be at least partially explained by differential recall by proxies and prodromal symptoms affecting phone use before diagnosis of the cases. We cannot rule out, however, residual confounding from sources we did not measure. Overall, our study provides no evidence of a causal association between wireless phone use and brain tumours in young people. However, the sources of bias summarised above prevent us from ruling out a small increased risk.

Soft x-ray measurements using photoconductive type-IIa and single-crystal chemical vapor deposited diamond detectors

Photoconductive detectors (PCDs) are routinely used alongside vacuum x-ray diodes (XRDs) to provide an alternative x-ray flux measurement at laser facilities such as HELEN at AWE Aldermaston, UK, and Omega at the Laboratory for Laser Energetics. To evaluate diamond PCDs as an alternative to XRD arrays, calibration measurements made at the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory are used to accurately calculate the x-ray flux from a laser-heated target. This is compared to a flux measurement using the Dante XRD diagnostic. Estimates indicate that the photoinduced conductivity from measurements made at Omega are too large, and calculations using the radiometric calibrations made at the NSLS agree with this hypothesis. High-purity, single-crystal, chemical vapor deposited (CVD) diamond samples are compared to natural type-IIa PCDs and show promising high resistivity effects, the corollary of which preliminary results show is a slower response time.

The Influence of Incubation Temperature on Bacterial Counts in a Meat Production System

Samples for microbial evaluation were taken from various surfaces including those on carcasses, and equipment at an abattoir, a wholesaler, and 10 different supermarkets. Samples were also taken of minced meat in retail display cabinets. These surfaces were monitored by means of a modified agar sausage technique. A total aerobic plate count (30°C for 24 - 48 h), a psychrotrophic count (5°C for 7 d), and a total aerobic plate count (25°C for 2 to 3 d) were investigated. Counts obtained at 30°C, yielded higher numbers than those acquired at 25°C. The accuracy of predicting the psychrotrophic population by means of a 25°C count, depends on the habitat and environmental conditions. To predict the spoilage population, a count at 25°C for 2 to 3 d can be a time saving and fairly accurate tool, provided that some equation is used to account for inherent differences. The conditions regarding habitat, environmental temperatures, and vectors should also be accounted for in the interpretation of results. The present work proved that to study a specific population, the quantitative study should be conducted at the revelant temperature (30°C for the total population, 7°C for a psychrotrophic population, and 37°C for a mesophilic population). Hence, to study the cold tolerant spoilage population encountered in a certain habitat (e. g. meat), it is advisable to do the quantitative survey at 7°C and further studies on the isolates made at this incubation temperature, could be done at 20 to 25°C.

A Quantitative Survey of a Meat Production Chain to Determine the Microbial Profile of the Final Product

Samples from carcasses, personnel surfaces, equipment, and minced meat, packaged and displayed in cabinets were taken at a city abattoir, a wholesaler, and 10 different supermarkets. Bacteria enumerated were 1) psychrotrophs; 2) Enterobacteriaceae ; 3) enterococci; 4) micrococci; 5) Pseudomonas spp; and 6) Brochothrix thermosphacta . The non integrated production system of abattoirs, wholesalers, and retailers yielded psychrotrophic and enterococci counts at retail which compared fairly well with those reported in literature, while the Enterobacteriaceae and micrococci counts were higher. Besides the psychrotrophs the pseudomonads were the most numerous group in the final product. Different surfaces were not sanitized with the same efficacy, while a general tendency towards lower counts at one supermarket group was monitored. The counts described 96% of the variation in the psychrotrophic count at the abattoir, while the success in using these counts in estimating the psychrotrophic count at the wholesaler and retailers was not as significant. At the abattoir the Enterobacteriaceae and psuedomonads were the biggest contributors to the psychrotrophic count, at the wholesaler the Enterobacteriaceae and micrococci counts, and at the retailers the micrococci and pseudomonads respectively. This indicates that Enterobacteriaceae might be common psychrotrophs in the meat production chain, maybe originating from the abattoir and wholesale environments.