A lot, I'd hazard the vast majority, of these things are pseudoscience at best (remember "microwaves will give you cancer"?). Does "challenging established views" means presenting hypotheses with empirical evidence or claiming that EMF is from Hell?

>It's a book that challenges some established views.

this doesnt answer the question because you can challenge established views scientifically (i.e., using data and evidence and testing, etc.) or unscientifically by screaming vaccines cause autism or whatever nonsense directly in the face of (and contrary to) data, evidence, and testing.