Desert dust outbreaks and respiratory morbidity in Athens, Greece

Stavroula-Myrto Trianti,Evangelia Samoli,Anna Karakatsani,Klea Katsouyanni,Sophia Rodopoulou,Spyros A Papiris

doi:10.1186/s12940-017-0281-x

Stavroula-Myrto Trianti, Evangelia Samoli + Show 4 more

Open Access

https://doi.org/10.1186/s12940-017-0281-x

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Abstract

BackgroundAmbient particulate matter (PM) has an adverse effect on respiratory morbidity. Desert dust outbreaks contribute to increased PM levels but the toxicity of desert dust mixed with anthropogenic pollutants needs clarification.MethodsWe identified 132 days with desert dust episodes and 177 matched days by day of the week, season, temperature and humidity between 2001 and 2006 in Athens, Greece. We collected data on regulated pollutants and daily emergency outpatient visits and admissions for respiratory causes. We applied Poisson regression models adjusting for confounding effects of seasonality, meteorology, holidays and influenza epidemics. We evaluated the sensitivity of our results to co-pollutant exposures and effect modification by age and sex.ResultsA 10 μg/m3 increase in PM10 concentration was associated with 1.95% (95% confidence interval (CI): 0.02%, 3.91%) increase in respiratory emergency room visits. No significant interaction with desert dust episodes was observed. Compared with non-dust days, there was a 47% (95% CI: 29%, 68%) increase in visits in dust days not adjusting for PM10. Desert dust days were associated with higher numbers of emergency room visits for asthma, chronic obstructive pulmonary disease and respiratory infections with increases of 38%, 57% and 60%, respectively (p < 0.001 for all comparisons). Analyses of respiratory hospital admissions provided similar results. PM10 effects decreased when adjusting for desert dust days and were further confounded by co-pollutants.ConclusionsDesert dust episode days are associated with higher respiratory emergency room visits and hospital admissions. This effect is insufficiently explained by increased PM10 levels.

Highlights

Ambient particulate matter (PM) has an adverse effect on respiratory morbidity
To further clarify the potential toxicity of desert dust mixed with anthropogenic pollutants, we investigated the effect of desert dust events on respiratory morbidity in the Southern Mediterranean metropolitan region of Athens, Greece
We focused on the effect of desert dust outbreaks and on the potential modifying effect on PM10 effects on respiratory morbidity

Summary

Introduction

Ambient particulate matter (PM) has an adverse effect on respiratory morbidity. Desert dust outbreaks contribute to increased PM levels but the toxicity of desert dust mixed with anthropogenic pollutants needs clarification. Transportation of desert dust, originating mainly from Sahara, is common in Europe, especially in the Mediterranean countries, resulting to increased concentrations of ambient particles with a median aerodynamic diameter < 10 μm (PM10) [1,2,3,4]. Recent evidence has shown that desert dust outbreaks alter particle size distribution as well as their chemical composition [9,10,11,12]. This effect depends on several factors such as the dust origin as well as the transportation route until the dust reaches the particular destination. From the limited number of studies carried out to establish the health effects due to the desert dust source, there are conflicting results [15]

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