This. Radioiodine can cause thyroid cancer but other than that when you're looking at a cluster of rare cancers don't look at radioactivity. On the other hand

This. Radioiodine can cause thyroid cancer but other than that when you're looking at a cluster of rare cancers don't look at radioactivity. On the other hand, we have had many cancer clusters that make the most sense as if they were infectious agents. Now, cancer is obviously no infectious--but we already know HPV is responsible for a lot of cancer, including strains that produce no symptoms. It's quite reasonable to think there might be other viruses that are carcinogenic but otherwise asymptomatic and thus staying below the radar.