There is no clear consensus on this question.  According to a 2016 report by the Health Physics Society, “…there are no known health risks that have been conclusively demonstrated to be caused by living near high-voltage power lines. But science is unable to prove a negative, including whether low-level EMFs are completely risk free. Most scientists believe that exposure to the low-level EMFs near power lines is safe, but some scientists continue research to look for possible health risks associated with these fields. If there are any risks such as cancer associated with living near power lines, then it is clear that those risks are small.” https://hps.org/hpspublications/articles/powerlines.html

However, in the Bioinitiative Report, compiled by an international group of scientists, researchers, and public health policy professionals on the biological effects of EMFs (electromagnetic fields), the content and implications of approximately 1800 new studies are summarized, and the conclusion drawn is that there is “scientific evidence of risk from chronic exposure to low-intensity electromagnetic fields”, such as emanate from transmission lines. www.bioinitiative.org/report/wp-content/…/sec01_2012_summary_for_public.pdf

Furthermore, there is strong concern among dairy farmers that stray voltage from high-voltage power lines causes increases in somatic cell counts, greater nervousness in cows, reduced milk production, and a higher incidence of clinical mastitis. https://puc.sd.gov/commission/dockets/electric/2013/EL13-028/guidelines.pdf