Downloads
DocumentsDate added
-
A Population-Based Prospective Cohort Study of Personal Exposure to Magnetic Fields during Pregnancy
-
19.02.2006
-
De-Kun Li, Roxana Odouli, Soora Wi, Teresa Janevic, Ira Golditch, T. Dan Bracken, Russell Senior, Richard Rankin, and Richard Iriye
Abstract:
To study the effect of magnetic fields on the risk of miscarriage, we conducted a population-based prospective cohort study among pregnant women within a large health maintenance organization. All women with a positive pregnancy test at less than 10 weeks of gestation and residing in the San Francisco area were contacted for participation in the study.
We conducted in-person interviews to obtain information on risk factors for miscarriage and other potential confounders. All participants were also asked to wear a magnetic fieldmeasuring meter for 24 hours and to keep a diary of their activities. Pregnancy outcomes were obtained for all participants by searching the health maintenance organization’s databases, reviewing medical charts, and telephone follow-up. We used the Cox proportional hazard model for examining the magnetic field-miscarriage association. A total of 969 subjects were included in the final analyses. Although we did not observe an association between miscarriage risk and the average magnetic field level, miscarriage risk increased with an increasing level of maximum magnetic field exposure with a threshold around 16 milligauss (mG). The rate ratio (RR) associated with magnetic field exposure 16 mG (vs 16 mG) was 1.8 [95% confidence interval (CI) 1.2–2.7]. The risk remained elevated for levels (in tertiles) of maximum magnetic field exposure 16 mG. The association was stronger for early miscarriages ( 10 weeks of gestation) (RR 2.2, 95% CI 1.2– 4.0) and among “susceptible” women with multiple prior fetal losses or subfertility (RR 3.1, 95% CI 1.3–7.7). After excluding women who indicated that their daily activity pattern during the measurements did not represent their typical daily activity during pregnancy, the association was strengthened; RR 2.9 (95% CI 1.6 –5.3) for maximum magnetic field exposure 16 mG, RR 5.7 (95% CI 2.1–15.7) for early miscarriage, and RR 4.0 (95% CI 1.4 –11.5) among the susceptible women. Our findings provide strong prospective evidence that prenatal maximum magnetic field exposure above a certain level (possibly around 16 mG) may be associated with miscarriage risk. This observed association is unlikely to be due to uncontrolled biases or unmeasured confounders. (EPIDEMIOLOGY 2002;13:9–20)
-
Hits: 989
-
-
Control Study of Residential and Personal Magnetic Field Measures and Miscarriges
-
19.02.2006
-
Geraldine M. Lee, Raymond R. Neutra, Lilia Hristova, Michael Yost, and
Robert A. Hiatt
Abstract:
We conducted a nested case-control study (177 cases, 550 controls) to assess the relation between retrospective magnetic field measures and clinical miscarriage among members
of the northern California Kaiser Permanente medical care system. We also conducted a prospective substudy of 219 participants of the same parent cohort to determine whether 12-week and 30-week exposure assessments were similar. We evaluated wire codes, area measures, and three personal meter metrics: (1) the average difference between consecutive levels (a rate-of-change metric), (2) the maximum level, and (3) the time-weighted average. For wire codes and area measures we found little association. For the personal metrics (30 weeks after last menstrual period), we found positive associations. Each exposure was divided into quartiles, with the lowest quartile as referent. Starting with the highest quartile, adjusted odds ratios and 95% confidence intervals were 3.1 (95% CI 1.6–6.0), 2.3 (95% CI 1.2– 4.4), and 1.5 (95% CI
0.8 –3.1) for the rate-of-change metric; 2.3 (95% CI 1.2– 4.4), 1.9 (95% CI 1.0 –3.5), and 1.4 (95% CI 0.7–2.8) for the maximum value; and 1.7 (95% CI 0.9 –3.3), 1.7 (95% CI 0.9 –3.3), and 1.7 (95% CI 0.9 –3.3) for the timeweighted average. The odds ratio conveyed by being above a 24-hour time-weighted average of 2 milligauss was 1.0 (95% CI 0.5–2.1). Exposure assessment measurements at 12 weeks were poorly correlated with those taken at 30 weeks. Nonetheless, the prospective substudy results regarding miscarriage risk were consistent with the nested study results.
(EPIDEMIOLOGY 2002;13:21–31)
-
Hits: 921
-
-
Subjective symptoms, sleeping problems, and cognitive performance living near mobile basestations
-
25.06.2006
-
BACKGROUND: The erection of mobile telephone base stations in inhabited areas has raised concerns about possible health effects caused by emitted microwaves. METHODS: In a cross-sectional study of randomly selected inhabitants living in urban and rural areas for more than one year near to 10 selected base stations, 365 subjects were investigated. Several cognitive tests were performed, and wellbeing and sleep quality were assessed. Field strength of high-frequency electromagnetic fields (HF-EMF) was measured in the bedrooms of 336 households. RESULTS: Total HF-EMF and exposure related to mobile telecommunication were far below recommended levels (max. 4.1 mW/m2). Distance from antennae was 24-600 m in the rural area and 20-250 m in the urban area. Average power density was slightly higher in the rural area (0.05 mW/m2) than in the urban area (0.02 mW/m2). Despite the influence of confounding variables, including fear of adverse effects from exposure to HF-EMF from the base station, there was a significant relation of some symptoms to measured power density; this was highest for headaches. Perceptual speed increased, while accuracy decreased insignificantly with increasing exposure levels. There was no significant effect on sleep quality. CONCLUSION: Despite very low exposure to HF-EMF, effects on wellbeing and performance cannot be ruled out, as shown by recently obtained experimental results; however, mechanisms of action at these low levels are unknown.
-
Hits: 920
-
-
A Review Of The Potential Health Risk Of Radiofrequency Fields From Wireless ...
-
07.07.2006
-
A Review Of The Potential Health Risk Of Radiofrequency Fields From Wireless Telecommunication Devices
-
Hits: 878
-
-
Acute mobile phone operation affects neural function in humans
-
19.02.2006
-
Clin Neurophysiol. 2002 Oct;113(10):1623-32 Croft RJ, Chandler JS, Burgess AP, Barry RJ, Williams JD, Clarke AR. OBJECTIVES
Mobile phones (MP) are used extensively and yet little is known about the effects they may have on human physiology. There have been conflicting reports regarding the relation between MP use and the electroencephalogram (EEG). The present study suggests that this conflict may be due to methodological differences such as exposure durations, and tests whether exposure to an active MP affects EEG as a function of time.
CONCLUSIONS
Active MPs affect neural function in humans and do so as a function of exposure duration. The temporal nature of this effect may contribute to the lack of consistent results reported in the literature.
-
Hits: 819
-
|
