Comment by Gnarl

@nuvious Apparently, it ain't that simple. If you lump together all brain tumour types, you won't see much happening, but once you split the stats into tumour types an interesting picture emerges. The incidence of glioblastoma's increases at pretty much the same rate as more benign types decrease in incidence. What to make of that? Well, something ubiquitous in the environment seems to be "upgrading" benign tumours into aggressive malign tumours. UK scientists did some work on this, here: https://www.hindawi.com/journals/jeph/2018/7910754/