Environmental exposures and respiratory outcomes in children.

Asthma is a complex condition where genetic and environmental interactions occur at critical periods in development. The focus of this review was the role of environmental exposures on asthma causation. Selected studies published in 2010 and 2011 were reviewed to illustrate the challenge in relating environmental exposure(s) on asthma causation and also to focus on some exposures currently thought to be important to asthma pathogenesis. Challenges in understanding how environmental exposures may translate into asthma causation are summarised. Inhaled and ingested exposures are described, including microbial products, swimming pools, diet and antenatal tobacco exposure. A final synthesis summarises what is currently understood about childhood asthma causation and what advice might be given to parents and governments interested in reducing asthma risk.