Bluetooth & microwave ovens also use the 2.4GHz band (only 801.11A uses 5GHz, and that's not licenced for Europe)), as do some model aircraft remote controls.

All, except microwave ovens, use frequency-hopping, so shouldn't block a WiFi signal to the degree that it stops working entirely. And a microwave shouldn't normally interfere unless it's either close, large, or leaky.