I finally got the type of mask I was looking for, to use on my bike when pollution is getting too bad, like today: well above 200 AQI. I tried all the other usual ones, none worked as my glasses became foggy and I could not really breathe.
This one (3M) works OK, as it has valves for incoming and outgoing air. Tested today for the first time.

So now, fully equipped with my little SUPERMAN bike – no joke, that is actually the BAT brand’s model name as I discovered a couple of weeks after buying it. It is a small and simple bike, no gears, giving me extra exercise when climbing a little or when it’s windy. I already bike fast enough like this, often passing e-bikes. But I would have preferred to ride SUPERWOMAN
Important is, it brings me around, even to Lido Hotel (twice). Rain, snow, freezing or sauna weather are normally not able to stop me.
Translation of the (Dutch) sign: “One more car less”!  (WEER EEN AUTO MINDER, from 11.11.11)
And if the crazies in DPRK start a chemical war I might be well enough prepared. The filter stops a lot of bad stuff! And it does not allow me to scold the unruly Chinese in my path.