Harving H, Korsgaard J, Dahl R
Department of Respiratory Diseases, Aarhus University Hospital, Denmark.
Allergy. 1994 Oct;49(9):713-8. doi: 10.1111/j.1398-9995.1994.tb02092.x.
Exposure to house-dust mites (Dermatophagoides spp.) was investigated in 30 asthmatic patients before and after moving to homes with mechanical ventilation systems. Median house-dust mite concentration was 110 mites per gram of mattress dust at the initial investigation and 20 mites per gram at the first follow-up after a mean of 4.7 months in the new homes. This was lower (P < 0.05) than counts in a control group of 23 asthmatic patients that had unchanged counts. At a second follow-up, after 15.0 months, mite counts in the study group were further reduced (P < 0.01) from initial values. Among 16 patients, with initial mite counts above the recommended threshold limit value (TLV) of 100 mites per gram of dust, the mite counts fell, in most cases, below this TLV. Air-exchange rates increased (P < 0.001) from a median value of 0.40 air changes per hour (ach) to 1.52 ach at the second follow-up investigation. Furthermore, a reduction (P < 0.01) was found in indoor absolute air humidity, with a median value of 5.6 g of water/kg. No such changes were found in the control group. The present study indicates that reduction of air humidity through an increased supply of fresh air may significantly diminish and, in some cases, even eliminate house-dust mites in homes.
在30名哮喘患者搬入配备机械通风系统的房屋前后，对其接触屋尘螨（尘螨属）的情况进行了调查。在初始调查时，每克床垫灰尘中的屋尘螨浓度中位数为110只螨，在新家平均居住4.7个月后的首次随访中为每克20只螨。这低于23名哮喘患者对照组的计数，且差异有统计学意义（P<0.05），该对照组的计数没有变化。在15.0个月后的第二次随访中，研究组的螨计数较初始值进一步降低（P<0.01）。在16名初始螨计数高于每克灰尘100只螨的推荐阈值（TLV）的患者中，大多数情况下螨计数降至该TLV以下。空气交换率从每小时0.40次换气（ach）的中位数增加到第二次随访调查时的1.52 ach（P<0.001）。此外，室内绝对空气湿度降低（P<0.01），中位数为5.6克水/千克。对照组未发现此类变化。本研究表明，通过增加新鲜空气供应来降低空气湿度，可能会显著减少，甚至在某些情况下消除家庭中的屋尘螨。
