Research conducted by Linus Bengtsson and fellow researchers from the Karonlinska Institute in Sweden and Columbia University in the USA revealed that mobile phone positioning data could be beneficial to monitor individual’s movements during disasters and outbreaks, as those in need can be tracked and assistance be dispatched within hours of receiving the data. The study was published in this week’s PLoS Medicine.

Because of the problems delivering essential relief assistance to the right locations and at the correct scale due to population movements following a disaster, researchers decided to conduct a geospatial investigation into the possibility of using position data from mobile phone SIMs (Subscriber Identity Modules) to estimate the magnitude and trends of population movements.

In collaboration with Digicel, Haiti’s largest mobile phone operator, the researchers retrospectively followed the positions of 1.9 million SIMs in Haiti before and after the January 2010 earthquake. They discovered their SIM estimations of population movements to be far more precise than speculated assumptions of estimates made immediately after the earthquake.

They subsequently tracked population movements via SIMs during the first few days of the cholera outbreak that followed the earthquake and found that estimates of population movements could be generated within 12 hours of receiving the data.

The findings reveal that routinely collected data of active SIM card movements in disaster-zones can provide estimates of magnitude, distribution and trends in population displacement. It furthermore proves that the method is beneficial for close to real-time monitoring of population movements during outbreaks of infectious diseases and suggests that this could be an effective approach to provide estimates of area-specific population sizes, and consequently lead to significant improvements in allocating relief supplies.

The authors recommend establishing relationships with mobile phone operators prior to emergencies as well as to implement and continue to evaluate this approach during future disasters, but state that this method may not be effective in all situations due to limited or no network coverage or damage to mobile phone towers because of the disaster. In addition, it should also be considered that some population groups, such as children or the elderly might not use mobile phones to the same extent as other groups.

Peter Gething of the University of Oxford, United Kingdom and Andrew Tatem from the University of Florida, USA, discuss the potential impact of mobile phone positioning data on disaster responses in an accompanying perspective article. Neither is involved in the study, but they point out challenges that must be addressed for developing the use of this technology approach as a disaster-response planning tool, including ways to examine cross-border population movements and the need for protocols to protect the privacy of data.

They write:

“Bengtsson and colleagues have demonstrated a valuable proof-of-concept of the use of phone data in disaster response, but substantial further work will likely be required before operational usage becomes common. While millions continue to be adversely affected by natural disasters, in an increasingly connected world where mobile phone ownership is becoming ubiquitous, these data will likely become a valuable component of the disaster response toolbox. Bengtsson and colleagues have taken the first step towards this full potential being realized.”

Written by Petra Rattue