There are many forest fires in Mexico at the moment, which is why Mexico City is in a pollution contingency plan. The fires are concentrated in avocado-growing regions: people are illegally burning down forest to turn it into avocado monocultures, and taking advantage of a loophole in land-use laws: https://www.sinembargo.mx/16-05-2019/3581975
The article says those avocados get exported to Japan, Canada, and Europe.
So if you live there, maybe try to eat something else?
@federicomena thank you, that information is not getting a lot of play up here in Canuckistan. I'll bear it in mind.