Sven Schmiedel

Leukaemia in young children living in the vicinity of German nuclear power plants.

A case control study was conducted where cases were children younger than 5 years (diseased between 1980 and 2003) registered at the german childhood cancer registry (GCCR). Population‐based matched controls (1:3) were selected from the corresponding registrars office. Residential proximity to the nearest nuclear power plant was determined for each subject individually (with a precision of about 25 m). The report is focused on leukaemia and mainly on cases in the inner 5‐km zone around the plants. The study includes 593 leukaemia cases and 1,766 matched controls. All leukaemia combined show a statistically significant trend for 1/distance with a positive regression coefficient of 1.75 [lower 95%‐confidence limit (CL): 0.65]; for acute lymphoid leukaemia 1.63 (lower 95%‐CL: 0.39), for acute nonlymphocytic leukaemia 1.99 (lower 95%‐CL: −0.41). This indicates a negative trend for distance. Cases live closer to nuclear power plants than the randomly selected controls. A categorical analysis shows a statistically significant odds ratio of 2.19 (lower 95%‐CL: 1.51) for residential proximity within 5 km compared to residence outside this area. This result is largely attributed to cases in previous studies of the GCCR (especially in the inner zone) as there is clearly some overlap between those studies. The result was not to be expected under current radiation‐epidemiological knowledge. Considering that there is no evidence of relevant accidents and that possible confounders could not be identified, the observed positive distance trend remains unexplained.

Mobile phone base stations and adverse health effects: phase 1 of a population-based, cross-sectional study in Germany

Objective: The aim of this first phase of a cross-sectional study from Germany was to investigate whether proximity of residence to mobile phone base stations as well as risk perception is associated with health complaints. Methods: The researchers conducted a population-based, multi-phase, cross-sectional study within the context of a large panel survey regularly carried out by a private research institute in Germany. In the initial phase, reported on in this paper, 30 047 persons from a total of 51 444 who took part in the nationwide survey also answered questions on how mobile phone base stations affected their health. A list of 38 health complaints was used. A multiple linear regression model was used to identify predictors of health complaints including proximity of residence to mobile phone base stations and risk perception. Results: Of the 30 047 participants (response rate 58.6%), 18.7% of participants were concerned about adverse health effects of mobile phone base stations, while an additional 10.3% attributed their personal adverse health effects to the exposure from them. Participants who were concerned about or attributed adverse health effects to mobile phone base stations and those living in the vicinity of a mobile phone base station (500 m) reported slightly more health complaints than others. Conclusions: A substantial proportion of the German population is concerned about adverse health effects caused by exposure from mobile phone base stations. The observed slightly higher prevalence of health complaints near base stations can not however be fully explained by attributions or concerns.

Mobile phone base stations and adverse health effects: phase 2 of a cross-sectional study with measured radio frequency electromagnetic fields

Objective: The aim of the cross-sectional study was to test the hypothesis that exposure to continuous low-level radio frequency electromagnetic fields (RF-EMFs) emitted from mobile phone base stations was related to various health disturbances. Methods: For the investigation people living mainly in urban regions were selected from a nationwide study in 2006. In total, 3526 persons responded to a questionnaire (response rate 85%). For the exposure assessment a dosimeter measuring different RF-EMF frequencies was used. Participants answered a postal questionnaire on how mobile phone base stations affected their health and they gave information on sleep disturbances, headaches, health complaints and mental and physical health using standardised health questionnaires. Information on stress was also collected. Multiple linear regression models were used with health outcomes as dependent variables (n = 1326). Results: For the five health scores used, no differences in their medians were observed for exposed versus non-exposed participants. People who attributed adverse health effects to mobile phone base stations reported significantly more sleep disturbances and health complaints, but they did not report more headaches or less mental and physical health. Individuals concerned about mobile phone base stations did not have different well-being scores compared with those who were not concerned. Conclusions: In this large population-based study, measured RF-EMFs emitted from mobile phone base stations were not associated with adverse health effects.

Integrated genetic and epigenetic analysis of bladder cancer reveals an additive diagnostic value of FGFR3 mutations and hypermethylation events.

The bladder cancer genome harbors numerous oncogenic mutations and aberrantly methylated gene promoters. The aim of our study was to generate a profile of these alterations and investigate their use as biomarkers in urine sediments for noninvasive detection of bladder cancer. We systematically screened FGFR3, PIK3CA, TP53, HRAS, NRAS and KRAS for mutations and quantitatively assessed the methylation status of APC, ARF, DBC1, INK4A, RARB, RASSF1A, SFRP1, SFRP2, SFRP4, SFRP5 and WIF1 in a prospective series of tumor biopsies (N = 105) and urine samples (N = 113) from 118 bladder tumor patients. We also analyzed urine samples from 33 patients with noncancerous urinary lesions. A total of 95 oncogenic mutations and 189 hypermethylation events were detected in the 105 tumor biopsies. The total panel of markers provided a sensitivity of 93%, whereas mutation and methylation markers alone provided sensitivities of 72% and 70%, respectively. In urine samples, the sensitivity was 70% for all markers, 50% for mutation markers and 52% for methylation markers. FGFR3 mutations occurred more frequently in tumors with no methylation events than in tumors with one or more methylation events (78% vs. 33%; p < 0.0001). FGFR3 mutation in combination with three methylation markers (APC, RASSF1A and SFRP2) provided a sensitivity of 90% in tumors and 62% in urine with 100% specificity. These results suggest an inverse correlation between FGFR3 mutations and hypermethylation events, which may be used to improve noninvasive, DNA‐based detection of bladder cancer.

Childhood leukemia in relation to radio frequency electromagnetic fields in the vicinity of TV and radio broadcast transmitters.

A case-control study of radio frequency electromagnetic fields (RF-EMFs) and childhood leukemia was conducted in West Germany. The study region included municipalities near high-power radio and TV broadcast towers, including 16 amplitude-modulated and 8 frequency-modulated transmitters. Cases were aged 0-14 years, were diagnosed with leukemia between 1984 and 2003, and were registered at the German Childhood Cancer Registry. Three age-, gender-, and transmitter-area-matched controls per case were drawn randomly from population registries. The analysis included 1,959 cases and 5,848 controls. Individual exposure to RF-EMFs 1 year before diagnosis was estimated with a field strength prediction program. Considering total RF-EMFs, the odds ratio derived from conditional logistic regression analysis for all types of leukemia was 0.86 (95% confidence interval: 0.67, 1.11) when upper (>or=95%/0.701 V/m) and lower (<90%/0.504 V/m) quantiles of the RF-EMF distribution were compared. An analysis of amplitude-modulated and frequency-modulated transmitters separately did not show increased risks of leukemia. The odds ratio for all types of leukemia was 1.04 (95% confidence interval: 0.65, 1.67) among children living within 2 km of the nearest broadcast transmitter compared with those living at a distance of 10-<15 km. The data did not show any elevated risks of childhood leukemia associated with RF-EMFs.

An evaluation of exposure metrics in an epidemiologic study on radio and television broadcast transmitters and the risk of childhood leukemia

Electric field strength values calculated by wave propagation modeling were applied as an exposure metric in a case-control study conducted in Germany to investigate a possible association between radio frequency electromagnetic fields (RF-EMF) emitted from television and radio broadcast transmitters and the risk of childhood leukemia. To validate this approach it was examined at 850 measurement sites whether calculated RF-EMF are an improvement to an exposure proxy based on distance from the place of residence to a transmitter. Further, the agreement between measured and calculated RF-EMF was explored. For dichotomization at the 90% quantiles of the exposure distributions it was found that distance agreed less with measured RF-EMF (Kappa coefficient: 0.55) than did calculated RF-EMF (Kappa coefficient: 0.74). Distance was a good exposure proxy for a single transmitter only which uses the frequency bands of amplitude modulated radio, whereas it appeared to be of limited informative value in studies involving several transmitters, particularly if these are operating in different frequency bands. The analysis of the agreement between calculated RF-EMF and measured RF-EMF showed a sensitivity of 76.6% and a specificity of 97.4%, leading to an exposure misclassification that still allows one to detect a true odds ratio as low as 1.4 with a statistical power of >80% at a two-sided significance level of 5% in a study with 2,000 cases and 6,000 controls. Thus, calculated RF-EMF is confirmed to be an appropriate exposure metric in large-scale epidemiological studies on broadcast transmitters.

Statistical power of disease cluster and clustering tests for rare diseases: A simulation study of point sources

Two recent epidemiological studies on clustering of childhood leukemia showed different results on the statistical power of disease cluster and clustering tests, possibly an effect of spatial data aggregation. Eight different leukemia cluster scenarios were simulated using individual addresses of all 1,009,332 children living in Denmark in 2006. For each scenario, a number of point sources were defined with an increased risk ratio at centroid, decreasing linearly to 1.0 at the edge; aggregation levels were administrative units of Danish municipalities and squares of 5, 12.5 and 25 km(2). Six statistical methods were compared. Generally, statistical power decreased with increasing size of aggregated units. In our scenarios, statistical tests based on individual data usually had lower statistical power than the best test based on aggregated data. In conclusion, spatial aggregation does not necessarily blur a clustering effect; this depends on the nature of clustering and the aggregated units.