http://nseej.com/رسائل/-137775/ Effectively-ventilated homes in dry climates include few dust mites. Homes with a relative humidity that consistently rises above 50 p.c can comprise greater than a hundred dust mites per gram of dust. To scale back mud mite numbers, a relative humidity of less than 50 % have to be maintained for several weeks. Sat, 31 May 2014 11:52:01 UTC en