Global Ramifications of Dust and Sandstorm Microbiota

Abstract

Dust and sandstorm events inject substantial quantities of foreign microorganisms into global ecosystems, with the ability to impact distant environments. The majority of these microorganisms originate from deserts and drylands where the soil is laden with highly stress-resistant microbes capable of thriving under extreme environmental conditions, and a substantial portion of them survive long journeys through the atmosphere. This large-scale transmission of highly resilient alien microbial contaminants raises concerns with regards to the invasion of sensitive and/or pristine sink environments, and to human health-concerns exacerbated by increases in the rate of desertification. Further increases in the transport of dust-associated microbiota could extend the spread of foreign microbes to new ecosystems, increase their load in present sink environments, disrupt ecosystem balance, and potentially introduce new pathogens. Our present understanding of these microorganisms, their phylogenic affiliations and functional significance, is insufficient to determine their impact. The purpose of this review is to provide an overview of available data regarding dust and sandstorm microbiota and their potential ramifications on human and ecosystem health. We conclude by discussing current gaps in dust and sandstorm microbiota research, and the need for collaborative studies involving high-resolution meta-omic approaches in conjunction with extensive ecological time-series studies to advance the field towards an improved and sufficient understanding of these invisible atmospheric travelers and their global ramifications.

Fig. 1.

—World map of drylands. Colors highlight regions with varying degrees of aridity. Major deserts (excluding Antarctica and the Arctic) are annotated. http://www.naturalearthdata.com/, last accessed July 21, 2018.

Fig. 2.

—A massive sandstorm blows off the west coast of Africa and over the Atlantic Ocean towards the Caribbean, on October 13, 2017. (A) A dust plume greater than 2,000 km in length could be seen over the Atlantic Ocean, 3 days later on October 16. (B) The dust plume was stretched over 4,000 km by day 4, October 17. The dust clouds reached the Caribbean by day 5 on October 18, covering Dominican Republic (Dom Rep) by October 19 (C), and moving towards the Bahamas (BHM) and Florida (Fla.) in the United States (USA). The natural color images were captured with the Moderate Resolution Imaging Spectroradiometer (MODIS) abroad NASA’s Satellites. Images courtesy of NASA Earthdata: https://worldview.earthdata.nasa.gov/, last accessed July 21, 2018.