Two pieces in the NYTimes today on the same scientific research.
Briefly the Amish in Indiana have small dairy farms with barns near the house, the Hutterites have larger farms with bigger barns away from the housing quarters. First exams of children from the two groups found significant differences in asthma, and in the underlying biology (too complex for me to summarize). Experiments with dust from the two applied to mice reproduced the same differences in biology.
It's part of a recent theory--children today suffer because their environments are too sterile, while early exposure to a more varied environment can reduce asthma--but significant in that the experiment identifies the chain of biologic events at issue: which dust from which source.
Soon we may see the Amish making more by selling dust from their farms than by selling milk. :-)
I also found the cultural differences between Hutterites and Amish interesting.