@Jd Martin had a valid point which is that if someone gets harmed on the property, they are going after the landlord.

(i.e. bedbugs, illegal substance, etc) good luck. 

It's just that some vital aspect of our character has changed that values show over substance & appearing bigger than ourselves.

Asbestos is only harmful in it's friable state, option #1 therfore to not touch if it's in good shape.

If one is paying the rent, no harm, no foul.

If you play a marginal game and say to yourself, what harm would one more do, you could keep going and going until you have a menagerie in there.

Now I'm realizing that for this whole idea to fit in line with my values I'd really like to use my investing to not only create a passive income for myself but also to contribute to making low socioeconomic urban neighborhoods better, particularly for kids who grow up in those areas, like helping them be less exposed to toxic substances and pollution, or have safer neighborhoods to play in, or more access to health/education resources. 

And if it still comes as a surprise to someone, what's the harm?

Perhaps that was a mistake in hindsight, although I was prepared to counter anyway, so maybe no harm done.

Rather, out of a feeling of responsibility to my former tenants, who I happily provided positive references for.The reality is that it does a landlord no good, and could do harm, to respond to a reference request.I have also gotten calls from landlords lobbying for a statutory and regulatory change.