Syndromic surveillance of air pollution incidents across international borders

Abstract

ObjectiveTo assess the impact on human health observed in associationwith periods of poor air quality which extended across internationalborders, affecting both London (UK) and Paris (France).In particular to quantify increased levels of emergency department(ED) attendances for asthma and wheeze/ difficulty breathing, andhow different age groups were affected. Here, using ED syndromicsurveillance from England and France, we aimed to identify anddescribe the acute impact of periods of particularly poor air qualityduring 2014 on human health in both London and Paris.IntroductionThe impact of poor air quality (AQ) on human health is a globalissue, with periods of poor AQ known to occur in multiple locations,across different countries at, or around the same time.The Public Health England (PHE) Emergency DepartmentSyndromic Surveillance System (EDSSS) is a public health legacyof the London 2012 Olympic and Paralympic Games, monitoringanonymised daily attendance data in near real-time from a sentinelnetwork of up to 38 EDs across England and Northern Ireland during2014.The Organisation de la Surveillance COordonnée des URgences(OSCOUR®) is a similar ED system coordinated by Santé publiqueFrance and has been running in France since 2004, establishedfollowing a major heatwave in 2003 to improve real-time publichealth surveillance capabilities. This truly national network includedaround 540 EDs in 2014.MethodsPeriods of poor AQ during 2014 in both London and Paris, whichwere likely to have an acute impact on human health were identifiedfrom the daily particulate monitoring data made available by themonitoring authorities in each location.1,2Daily ED syndromic surveillance data for selected health indicators(asthma, difficulty breathing type attendances and myocardialischaemia (MI)) were gathered from EDSSS and OSCOUR®forLondon and Paris respectively.The standard method used for the daily statistical analysis ofEDSSS(RAMMIE method),3was also applied to OSCOUR®and usedto identify days where the numbers of attendances reported in boththe EDSSS and OSCOUR®systems were statistically significantlydifferent to the historical data, based on the previous 2 years.ResultsDistinct differences were identified between the impact observedon different age groups, with increased asthma ED attendances forchildren during/ following some AQ events, though a greater impactwas observed in adults around other AQ events.Increases in ED attendances for asthma were identified at severalpoints where no AQ events were reported, both short lived spikesduring the summer period in particular and a more sustained increasetowards the start of autumn.ConclusionsDespite EDSSS and OSCOUR®having been developed in differentcountries, at different times and resulting from different drivers, bothsystems use very similar syndromic indicators to identify asthma,difficulty breathing and MI attendances. Using these systems theshort term impacts of multiple AQ events which crossed internationalboundaries were successfully identified and investigated by Englishand French public health authorities.Periods of poor AQ are not the only events that can affect asthmatype attendances as identified here, thunderstorm activity and thebeginning of a new academic year also coincided with increasedattendances in both London and Paris.Harmonisation of surveillance methods across differentinternational jurisdictions is possible and there is the potential forfuture cross border surveillance and harmonisation of methodsbetween countries to improve international health surveillance andearly warning of potential public health threats affecting multiplecountries.