I live in central London and because of that (or maybe this is how it is everywhere?) I feel like I'm always passing smokers. People smoking in the middle of winter wonderland, on the street, outside pubs etc... I myself don't smoke, neither does my partner, and I do try to hold my breath when I walk past these people but there's only so much I can do - I can't always notice every smoker and I'm not an Olympic swimmer so can't hold my breath the entire time I walk past a pub. How much harm will this cause to eggs? Currently embryo banking.