Friday, November 6, 2009

Research Log

A.TOPIC: we should remove cell phone.
B. reseach:

1. Mobile Phone Use and Risk of Acoustic Neuroma: Results of the Interphone Case-Control Study in Five North European Countries
Schoemaker, M. J. Swerdlow, A. J.
Source: British Journal of Cancer; 10/3/2005, Vol. 93 Issue 7, p842-848, 7p
There is public concern that use of mobile phones could increase the risk of brain tumours. If such an effect exists, acoustic neuroma would be of particular concern because of the proximity of the acoustic nerve to the handset. We conducted, to a shared protocol, six population-based case–control studies in four Nordic countries and the UK to assess the risk of acoustic neuroma in relation to mobile phone use. Data were collected by personal interview from 678 cases of acoustic neuroma and 3553 controls. The risk of acoustic neuroma in relation to regular mobile phone use in the pooled data set was not raised (odds ratio (OR)=0.9, 95% confidence interval (CI): 0.7–1.1). There was no association of risk with duration of use, lifetime cumulative hours of use or number of calls, for phone use overall or for analogue or digital phones separately. Risk of a tumour on the same side of the head as reported phone use was raised for use for 10 years or longer (OR=1.8, 95% CI: 1.1–3.1). The study suggests that there is no substantial risk of acoustic neuroma in the first decade after starting mobile phone use. However, an increase in risk after longer term use or after a longer lag period could not be ruled out.

2. Effect of cell phone usage on semen analysis in men attending infertility clinic: an observational study.
Authors: Agarwal, Ashok1
Source:Fertility & Sterility; Jan2008, Vol. 89 Issue 1, p124-128, 5p
Objective: To investigate the effect of cell phone use on various markers of semen quality. Design: Observational study. Setting: Infertility clinic. Patient(s): Three hundred sixty-one men undergoing infertility evaluation were divided into four groups according to their active cell phone use: group A: no use; group B: <2 h/day; group C: 2–4 h/day; and group D: >4 h/day. Intervention(s): None. Main Outcome Measure(s): Sperm parameters (volume, liquefaction time, pH, viscosity, sperm count, motility, viability, and morphology). Result(s): The comparisons of mean sperm count, motility, viability, and normal morphology among four different cell phone user groups were statistically significant. Mean sperm motility, viability, and normal morphology were significantly different in cell phone user groups within two sperm count groups. The laboratory values of the above four sperm parameters decreased in all four cell phone user groups as the duration of daily exposure to cell phones increased. Conclusion(s): Use of cell phones decrease the semen quality in men by decreasing the sperm count, motility, viability, and normal morphology. The decrease in sperm parameters was dependent on the duration of daily exposure to cell phones and independent of the initial semen quality.

3. Analysis of RF Exposure in the Head Tissues of Children and Adults
Authors: J Wiart
Physics in Medicine & Biology; Jul2008, Vol. 53 Issue 13, p3681-3695, 15p
This paper analyzes the radio frequencies (RF) exposure in the head tissues of children using a cellular handset or RF sources (a dipole and a generic handset) at 900, 1800, 2100 and 2400 MHz. Based on magnetic resonance imaging, child head models have been developed. The maximum specific absorption rate (SAR) over 10 g in the head has been analyzed in seven child and six adult heterogeneous head models. The influence of the variability in the same age class is carried out using models based on a morphing technique. The SAR over 1 g in specific tissues has also been assessed in the different types of child and adult head models. Comparisons are performed but nevertheless need to be confirmed since they have been derived from data sets of limited size. The simulations that have been performed show that the differences between the maximum SAR over 10 g estimated in the head models of the adults and the ones of the children are small compared to the standard deviations. But they indicate that the maximum SAR in 1 g of peripheral brain tissues of the child models aged between 5 and 8 years is about two times higher than in adult models. This difference is not observed for the child models of children above 8 years old: the maximum SAR in 1 g of peripheral brain tissues is about the same as the one in adult models. Such differences can be explained by the lower thicknesses of pinna, skin and skull of the younger child models.

1 comment: