Hi Schorty, Optera, & WildBraas !
I've been working with Pi-C to update Bio Industries, we have a big version in the works, and I had the same idea as you when playing. Gardens in BI are just missing this feature, a pollution sensor (to, for example, turn them off when the air is clean, to avoid using extra material)
We could probably code it from scratch, but you've done most of the work so I was wondering if you'd be ok if we borrowed some pieces of code from you with credit? (I see you have a pretty loose license but I prefer asking beforehand !)
I'd create the whole graphical aspect myself.

Coded from scratch now (OK, I did borrow eradicator's elegant loop opener for event distribution), approaching the thing from an entirely different angle.

Sorry for beeing late: Just go ahead. The License states, that you can do whatever you want with my code :D
Giving credit is nice :)