Exhaled NO and ventilation, indoor allergens, fungal contamination and particles in homes at winter time in Wuzhou, South China

Guihong Cai, Dan Norbäck. Dept. of Medical Science, Uppsala University, Uppsala, Sweden

Author address: 

Dept. of Medical Science, Uppsala University, Uppsala, Sweden


There is little data on indoor pollutants in homes in south China and exhaled NO in Asians. Methods: Totally 40 homes with 130 subjects (12-65 y) were arbitrary selected in Wuzhou, a small city in South China. We monitored exhaled Nitric Oxide (NO) with NIOX-MINO, and collected dust by vacuum cleaning, swabbing of door frames, and in Petri dishes. Fungal DNA was analysed by quantitative PCR. Results: Median CO2 was 508 ppm in the bedroom, 394 ppm in the living room, 8% had levels above 1000 ppm. Median PM 10 was 356 µg/m3 and ultra-fine particles (UFP) 26218 pt/cc in the living room. Outdoor median PM 10 was 321 µg/m3 and UFP 48126 pt/cc. Median indoor NO2 was 45 µg/m3. Median formaldehyde was 6 µg/m3 and acetaldehyde 7 µg/m3. In swab samples (in CE/m2), the median levels of total fungal DNA was 3.14*108, Aspergillus/Penicillium (Asp/Pen) DNA 9.46*107, A. Versicolor DNA 2.55*105, Streptomyces DNA 1.43*103, respectively. In Petri dish samples (in CE/m2/day), the median levels for total fungal DNA was 1.06*108, Asp/Pen DNA 3.04*107, A. Versicolor DNA 1.02*105, Streptomyces DNA 57, respectively. Median cat and dog allergens in bedroom dust was 160 and 183 ng/g dust, respectively. The number of smokers was associated with ultra-fine particle levels (P=0.047). Median exhaled NO level was 11 ppb (IQR 8-16); only six had NO above 25 ppb. Conclusion: The homes were well ventilated with low levels of pet allergens, formaldehyde and acetaldehyde, but high levels of fungal DNA, PM 10, UFP, and NO2. Exhaled NO was lower than in western countries. The low levels of exhaled NO, despite high pollution levels, may indicate a genetic difference or other protective factors.

abstract No: 


Full conference title: 

20th European Respiratory Society conference
    • ERS 20th (2010)