I really am not sure of the dangers, have always been aware that there are concerns and do agree that they do not look very nice and seem to stand out. However, it would not put me off buying a house near them if I liked the house and the area and the price was right. I live not all that far from electricity pylons and also not all that far from the sewage works :) and was always amazed when the houses around me were built that those directly under the overhead power lines and close to the pylons sold just as quickly as those that were not and for the same prices. I am also close to the River Nidd and some beautiful countryside and walks. I am in an area where houses sell well but having said all of this I would still have some concerns about re-selling in the future, just maybe not enough to put me off.