My family have been healthier in the 2 1/2 years that we've lived in the UK. I'm reluctant to put that in print though. Murphy's Law we'll get typhoid now. The amazing thing is that we traveled for 5 months (trains, planes, public restrooms, friends' houses)and got not one bug, and then my kids started school here and caught colds the first week. Maybe the real reason we've been healthier is that our kids have gotten older and don't pass along quite so many germs to us anymore!
Both my kid's asthma is quite a bit better here. I told the doctorn that and he shook his head saying "Well, you've been lucky." I wondered whether it wasn't because we moved from a big city with lots of air pollution in the US, to a small town out in the country here?
That said, my husband's asthma was ok in the US and is ok here at our house, but whenever he goes to his parents he wheezes absolutely the whole time he's there. My son wheezes there too. Both have molds as a big trigger for asthma. I wondered whether it wasn't these old stone houses which store damp in the walls? My in-laws house is a lovely old cottage and they don't dehumidify. They have chronic respiratory illnesses. We bought a dehumidifyer and you can't believe the amount of moisture it pulls out of even a small closet. Also, my house doesn't smell musty.
I don't really know anything for sure. Asthma is complicated and I feel like the only way to figure out what makes it better or worse is to keep trying stuff.