Epidemiologic study of residential proximity to transmission lines and childhood cancer in California: description of design, epidemiologic methods and study population.

We conducted a large epidemiologic case-control study in California to examine the association between childhood cancer risk and distance from the home address at birth to the nearest high-voltage overhead transmission line as a replication of the study of Draper et al. in the United Kingdom. We present a detailed description of the study design, methods of case ascertainment, control selection, exposure assessment and data analysis plan. A total of 5788 childhood leukemia cases and 3308 childhood central nervous system cancer cases (included for comparison) and matched controls were available for analysis. Birth and diagnosis addresses of cases and birth addresses of controls were geocoded. Distance from the home to nearby overhead transmission lines was ascertained on the basis of the electric power companies' geographic information system (GIS) databases, additional Google Earth aerial evaluation and site visits to selected residences. We evaluated distances to power lines up to 2000 m and included consideration of lower voltages (60-69 kV). Distance measures based on GIS and Google Earth evaluation showed close agreement (Pearson correlation >0.99). Our three-tiered approach to exposure assessment allowed us to achieve high specificity, which is crucial for studies of rare diseases with low exposure prevalence.

Distance to high-voltage power lines and risk of childhood leukemia--an analysis of confounding by and interaction with other potential risk factors.

We investigated whether there is an interaction between distance from residence at birth to nearest power line and domestic radon and traffic-related air pollution, respectively, in relation to childhood leukemia risk. Further, we investigated whether adjusting for potential confounders alters the association between distance to nearest power line and childhood leukemia. We included 1024 cases aged <15, diagnosed with leukemia during 1968-1991, from the Danish Cancer Registry and 2048 controls randomly selected from the Danish childhood population and individually matched by gender and year of birth. We used geographical information systems to determine the distance between residence at birth and the nearest 132-400 kV overhead power line. Concentrations of domestic radon and traffic-related air pollution (NOx at the front door) were estimated using validated models. We found a statistically significant interaction between distance to nearest power line and domestic radon regarding risk of childhood leukemia (p = 0.01) when using the median radon level as cut-off point but not when using the 75th percentile (p = 0.90). We found no evidence of an interaction between distance to nearest power line and traffic-related air pollution (p = 0.73). We found almost no change in the estimated association between distance to power line and risk of childhood leukemia when adjusting for socioeconomic status of the municipality, urbanization, maternal age, birth order, domestic radon and traffic-related air pollution. The statistically significant interaction between distance to nearest power line and domestic radon was based on few exposed cases and controls and sensitive to the choice of exposure categorization and might, therefore, be due to chance.

[French general practitioners and electromagnetic fields]. / Les médecins généralistes français face aux champs électromagnétiques.

OBJECTIVE: To assess the perception of risk of general practitioners (GPs) about electromagnetic fields (EMF), their sources of information, as well as their patients' level of concern. METHODS: Six hundred French GPs were selected according to the quotas method. They were asked to answer 24 items via an electronic questionnaire using the Computer-Assisted Web Interviewing (CAWI) method. RESULTS: The GPs know the main EMF sources: cell phone towers, cell phones, power-lines, microwave ovens and WiFi networks. Patients mostly complain or worry about the first three sources and ask their GP for information about these. GPs themselves search for information in the mainstream media rather than in the usual scientific and medical press. As a consequence, their knowledge about potential risks of EMF is deemed rather crude. DISCUSSION AND CONCLUSION: The GPs are sensitive to environmental concerns, particularly regarding EMF exposure. However, according to the results analysis, they do not have the same approach because of an obvious lack of mastery in a complex and poorly informed situation. A serious educational effort is essential and would be welcomed by practitioners, who are aware of their responsibilities in terms of counseling, diagnosis and care.

[Practical aspects of taking measurements of electromagnetic fields in the surrounding of overhead transmission lines]. / Praktyczne aspekty wykonywania pomiarów pól elektromagnetycznych w otoczeniu napowietrznych linii elektroenergetycznych.

Identification of electromagnetic fields in the vicinity of high voltage overhead transmission lines requires taking measurements and determining, on their basis, the maximum values of electric (Emax) and magnetic (Hmax) field strength, as well as the width of the area with electric field strength exceeding 1 kV/m. Measurements should be carried out in the places, where the distance between phase wires and the ground is smallest, and their results converted to conditions expected at the most disadvantageous parameters of the work of line in terms of their effect on the environment. This requires taking into consideration the maximum voltage of the transmission line, as well as the highest acceptable temperature of wires. In a single-circuit line, convertion of the measured values to expected maximum values of Emax and Hmax is not difficult, although it requires knowledge of cross-profiles in spans, in which measurements were taken. However, recounting the values of magnetic field strength produced by two-circuit lines creates a serious problem. Since in the majority of cases, the measurements in the surrounding of two-circuit lines are carried out at asymmetrical currents in both circuits, converting their results to symmetrical currents of the lines is practically impossible. Therefore, the results of the measurements of magnetic field strength carried out at the asymmetrical current of a two-circuit line cannot provide the basis for assessing the possibility of exceeding the allowable value of magnetic field intensity determined in the binding regulations. Such an assessment can only be done on the basis of the results of relevant calculations.

Bilateral sternobronchial fistula after coronary surgery--are the retained epicardial pacing wires responsible? A case report.

BACKGROUND: Temporary epicardial pacing wires are routinely used during cardiac surgery; they are dependable in controlling postoperative arrhythmias and are associated with low morbitity. CASE REPORT: We report a case of sternobronchial fistula formation induced by the existence of retained epicardial pacing wires in a patient who underwent coronary surgery ten years ago. CONCLUSION: Reported complications of retained epicardial pacing wires are unusual. We present this case in order to include it to the potential complications of the epicardial pacing wires.