No idea, mate.

I read this more than 20 years ago, so the "EM" part might be off, but the article revolved around the fact that there was an abnormally high number of former Washington embassy employees from certain time period that died of blood cancer. The cause was stated to be some kind of external irradiation.

Certainly there could be other pathways to cancer. We know there are lots of things that contribute to cancer other than ionizing radiation.

For example, improperly functioning immune system can lead to cancer. It could be there is a pathway using EM not well understood.