[HerrBlucher]

Both my parents smoked like chimneys all through my childhood and the childhood of my 4 siblings. My mother likely smoked while she breastfed us. The car was always filled with smoke too. We grew up in smoggy southern california when it was at its worst in the 1960’s. We are all in our 60’s now and none of us have had any lung issues whatsoever. We had several pets and none of them had any lung issues either or died of cancer of any type.

[EinNYC]

Both my parents smoked like chimneys all through my childhood and I got asthma for the rest of my life as a result. My father died of lung cancer. Smoking undoubtedly exacerbated my mother's heart issues and may well have accelerated her Alzheimers. Don't even begin to blather to me that secondhand smoke is harmless.

And, I think it's cruel to subject pets, with them being captive in your environment, to secondhand smoke. It can't in any way be good for them if it downright doesn't give them cancer or respiratory problems.