There are 3 studies that match your criteria.
Criteria: Freq Range=0 - 300 Hz (Static, ELF),Study Type=Epidemiology,Study Subtype=Case Control Cancer Study,Status=Ongoing

Details - Project ID 303
Lab	Japan
Study Design	50-60 Hz (ELF) epidemiology feasibility study in Japan
Summary	(ongoing)
Citation
Details - Project ID 1689
Lab	Sao de Publica, Brazil
Study Design	Power line (ELF) exposure exposure and correlations with childhood leukemia in Brazil
Summary
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Details - Project ID 1805
Lab	Imperial College, London, UK
Study Design	50 Hz powerline exposure in the UK and case control evaluation of associations with various cancers
Summary
Citation