The levels of oestrogen in water? For many years now the levels of female hormones in the water supply has been steadily building up, due to the use of hormonal contraception, which cannot be filtered out of the waste water, as well as agricultural practices which contaminate water due to run off from fields into the water supply. This has been affecting marine life for a long time, so it stands to reason that it’s also affecting humans.
I’m sure there’s other factors too, there seems to be a disproportionate number of SEN teens confused about their gender, so maybe it’s a feeling of not belonging for them which leads them to think that they must have been born in the wrong body and that’s why they don’t fit in. But is it possible that there is a rise in genuine confusion in males feeling like females due to the female hormones they’re ingesting every day?
Disclaimer - I’m not a scientist so happy to be corrected!