Meta-analysis on Hygienic Indexes in Central Air Conditioning Ventilation Systems in Public Buildings in China

Objectives To analyse the hygienic indexes in central air conditioning ventilation systems in public buildings in China.

Methods Studies about the hygienic indexes in central air conditioning ventilation systems in public buildings during 2006-2013 were searched by PubMed, CNKI, VIP, and Wanfang databases. Pooled estimates were summarized by Meta-analysis.

Results 138 eligible studies were included in this Meta-analysis, related to 22 provinces, autonomous regions and municipalities. The pooled qualified rate of PM₁₀, total bacteria count, total fungi count, and β-hemolytic streptococcus in supply air samples were 72.11%(95% CI 65.05%~78.65%), 71.41%(95% CI 66.06%~76.47%), 84.14%(95% CI 80.05%~87.84%) and 99.55%(95% CI98.97%~99.89%), respectively. The qualified rates of dust, total bacteria count, and total fungi count on the ducts surface were 81.14%(95% CI 75.30%~86.36%), 89.05%(95% CI 85.45%~92.20%), 87.26%(95% CI 83.48%~90.61%), respectively. There were no significant differences (P < 0.05) of the pooled qualified rates of almost hygienic indexes between the southern and northern areas in China, among the years from 2006 to 2013, among different public buildings of hotels, supermarkets and hospitals, and among different cities, through stratified comparison). However, the pooled qualified rate of almost hygienic indexes showed a rising trend, and the pooled qualified rate of hygienic indexes in supply air samples is lower than the pooled qualified rate of hygienic indexes on ducts surface.

Conclusions The hygienic management of central air conditioning ventilation systems in public buildings in China has obtained obvious effect, but it's still needed to supervise and monitor the hygienic indexes in air supplied outlet in central air conditioning ventilation systems.