Along the last decades, an increase in dust storm frequency and dust emission from the main arid zones of the north hemisphere have been determined. This fact is caused by high temperatures and the increase in drought periods related to climate change, as well as the increase in soil erosion due to anthropic causes. On the other hand, several adverse effects on health have been also identified, including an increase in mortality during dust storms or “haboob”, both for source regions (Figures Ia and Ib) and for further away zones but receiving mineral dust due to long-range transport processes (Figure II).
Figure Ia. A haboob engulfs Phoenix on July 5, 2011. (Photo Credit: EarthSky.org). From Haboobs: One of Arizona’s most underrated weather hazards. By Taylor Dayton, Arizona Sonora News on May 11, 2017.
Figure Ib. A haboob seen from above moving into Phoenix on Aug. 21, 2016. (Photo Credit: Tyler Herrick). Source: “Haboobs: One of Arizona’s most underrated weather hazards”. By Taylor Dayton, Arizona Sonora News on May 11, 2017.
On those countries of south Europe bordering the Mediterranean sea, African mineral dust apportions are the principal natural contribution to PM10 (Figure II) and they produce exceedances of the PM10 daily limit value for health protection in regional background and kerbside stations. Adding to this, an increase in mortality has been observed in many south European cities during events of long-range transport of African mineral dust. Notwithstanding, the reasons for this increase in mortality are not clear yet.
Figure II. Thick cloud of African mineral dust, transported from the African mainland to the Iberian Peninsula. Image acquired on 21 February 2016 by the Moderate Resolution Imaging Spectroradiometer (MODIS) on board the Aqua satellite. NASA image courtesy the LANCE/EOSDIS Rapid Response.