The proposed research will estimate the attributable fraction (AF) for childhood leukemia (CL) from exposures to power frequency magnetic fields(MFs) using novel methods for exposure assessment. CL is the most common childhood cancer and a significant factor in childhood morbidity and mortality, accounting for about 2400 deaths annually in the United States. There was a cumulative increase of 20% in the rate of incidence of CL over the period 1973-1991 (Landrigan, 1995). Data on exposure and risk--rather than summary risk estimates--will be taken from almost all available epidemiologic studies on this topic. The resulting AF estimates and underlying epidemiologic methods will contribute directly to development of hazard assessment models for the potential influence of EMFs on CL. In pilot work, epidemiologic data from several studies on EMFs and CL have been acquired, put into a database, and verified to reproduce published risk estimates. The proposed advances in epidemiologic research methodology and exposure assessment require these specific aims: 1) compilation of a larger database on CL and MF exposures from existing epidemiologic studies; 2) creation of a MF-based exposure score for standardized exposure assessments; 3) estimation of the total exposed population; 4) incorporation of a dose-response model; 5) estimation of AF from the database (unlike meta-analyses which use summary data); 6) conduct sensitivity analyses to identify critical assumptions and needs for better data. Because major steps have already been taken towards these goals, it will be possible to complete this work within funding available from a R03 grant. Follow-on work could apply the method to other diseases of children and adults potentially caused by EMF exposure.
| Greenland, S; Sheppard, A R; Kaune, W T et al. (2000) A pooled analysis of magnetic fields, wire codes, and childhood leukemia. Childhood Leukemia-EMF Study Group. Epidemiology 11:624-34 |
