Residential proximity to electrical power lines of different voltage in relation to childhood leukemia was investigated through a case-control study undertaken in Greece during 1993–1994. The study comprised 117 incident cases of childhood leukemia and 202 age-, gender- and place-of-residence-matched controls. Four measures of exposure to magnetic fields were developed, using data provided by the Public Power Corporation of Greece: Voltage (V) divided by the distance (d), V/d2, V/d3 and an adaptation of the Wertheimer-Leeper code. Conditional-logistic-regression modeling was used to adjust for potential confounding influences of 18 variables. No significant trends of childhood leukemia risk with increasing exposure levels were noted, nor were there statistically significant elevations of disease risk at the higher exposure levels in each measure of exposure. These results do not support a causal link between residential proximity to electrical high-voltage wires and childhood leukemia risk, but in themselves do not refute a weak empirical association. Int. J. Cancer 73:345–348, 1997. © 1997 Wiley-Liss, Inc.

Electrical power lines and childhood leukemia: A study from Greece

The relation between exposure to electric and magnetic fields in the home, as assessed by measurements, wiring configuration, and self-reported appliance use, and risk of leukemia was investigated in a case-control study among children from birth to age 10 years in Los Angeles County, California. Cases were ascertained through a population-based tumor registry from 1980 to 1987. Controls were drawn from friends and by random digit dialing. Interviews were obtained from 232 cases and 232 controls. Available for analysis were measurements of the magnetic field in the child's bedroom over 24 hours or longer (164 cases and 144 controls), spot measurements of magnetic and electric fields (140 cases and 109 controls), and wiring configuration (219 cases and 207 controls). No clear associations between leukemia risk and measured magnetic or electric fields were seen. An association between the Denver Wertheimer-Leeper wiring configuration and childhood leukemia risk was observed (odds ratio for very high relative to very low current and underground configuration combined = 2.15, 95% confidence interval 1.08-4.28; p for trend = 0.008) and was not substantially altered by adjustment for potential confounding factors. Cases were more likely than controls to report use of several appliances that produce high electric and magnetic fields. Our results support an association between childhood leukemia risk and wiring configuration, but not direct measurements of electric and magnetic fields.

Exposure to residential electric and magnetic fields and risk of childhood leukemia. Final report

Public concern about electromagnetic fields from power systems calls for a proper evaluation of continuous exposure of the population to power frequency magnetic fields, especially those from overhead transmission lines, felt as impacting human activities and the environment. Sophisticated measuring and computing tools now available for continuous exposure evaluation may be ineffective without a sound knowledge of power system theory and of typical line loads. In this perspective, the paper firstly recalls the fundamentals of power line magnetic field calculation and shows that a proper use of historical load databases is essential for associating residential magnetic fields with load diagrams of the lines. Then, innovative heuristic formulas for ac double-circuit overhead transmission lines with independent circuits are proposed, so that line databases can be used accounting for phase-shift effects between line currents in an easier and faster way. Such formulas provide a good approximation, via one single fixed-load calculation, of the median/mean magnetic field over a reference operational period of the line (e.g., one year) and are successfully applied to an existing line, resorting to a historical load database of the line recorded from 1994 to 2001.

Evaluation of Continuous Exposure to Magnetic Field From AC Overhead Transmission Lines Via Historical Load Databases: Common Procedures and Innovative Heuristic Formulas

This paper examines the results of previous wire code research to determines the relationship with childhood cancer, wire codes and electromagnetic fields. The paper suggests that, in the original Savitz study, biases toward producing a false positive association between high wire codes and childhood cancer were created by the selection procedure.

T. Jones

Papers

EMF wire code research