Impact of ambient air pollution and wheeze-associated disorders in children in Southeast Asia: a systematic review and meta-analysis.

Several systematic reviews have been conducted so far to examine the effect of air pollution on respiratory diseases, but there has not been a corresponding meta-analysis to estimate the effect sizes for wheeze-associated diseases/disorders, which is one of the leading causes of emergency department visits and hospitalizations for children worldwide. The aim of this review is to systematically evaluate the relationship between air pollution and risk of wheeze-associated disorders in children in Southeast Asia. We searched the relevant computerized databases (PubMed, EMBASE, Web of Science, Scopus and Cochrane library) for indexed publications up to July 2018. Finally, eight studies were qualified for performing a random-effect meta-analysis to compute the pooled effect sizes. The results show that each increase of 10 μg/m3 in concentrations of PM2.5, PM1 was associated with 1-2% increase in risk of wheeze-associated disorders. Positive associations were found for PM10, SO2, NO2, NOx but no association was found for CO and O3. We confirmed the strong effect of fine particulate matters on respiratory health and recommend an updated meta-analysis should be done when more studies are available.