Factorio Forums

Too much carbonoxide for plants means: a lot of. The concentration must be high to perturb cellular respiration.
Also concentration of nitric acid must me high or very long to kill the plants. And don't be silly: its impossible to create the acid rain only around the factory. The atmosphere is constantly moving and mixing masses of air.

I think that pollution in Factorio is created from various poisonous dusts: of raw ores, toxic heavy metals, plastic byproducts, alkali ashes, etc. It sediments around the factory and kills everything. Spawners absorb ashes actively, so it creates for them the biggest impact.

You say it like this game is pollution simulator.

I hope that there will be ways to adjust the sensitivity of the environment, or even for each individual trees.