TY - JOUR T1 - Highlights from this issue JF - Archives of Disease in Childhood JO - Arch Dis Child SP - ii LP - ii DO - 10.1136/archdischild-2018-315883 VL - 103 IS - 9 AU - Nick Brown Y1 - 2018/09/01 UR - http://adc.bmj.com/content/103/9/ii.abstract N2 - Progress in the reduction of asthma morbidity in high income countries has effectively stalled over the last decade. One explanation relates to individual management but environmental exposures are likely to be at least at important. The WHO and EU recommendations differ on what constitute acceptable levels of fine particulate matter (PM2.5), the main sources of which are vehicle emissions, home coal burning and power stations. The former is more stringent on PM2.5, European legislation being stricter with regard to nitrogen dioxideChappuy and colleagues ( see page 828 ) undertook an ambitious 5 year study in Paris assessing the association between PM2.5 levels and asthma exacerbations. They assessed more than 1.2 million ED visits of which 47 000 were diagnosed as asthma and examined the association with air quality using data on nitrogen dioxide, ozone and PM2.5 collected on an hourly basis from the regional meteorological laboratory and adjusted for potential climatic and RSV density. In the multivariable model (which made some assumptions on population stability and generalisability of the pollution measures) only the PM2.5 remained predictive of incidence of asthma episodes, and at a watershed level of 13 mcg/m2 below that … ER -