Project Details

An example of the Safecast system built to measure radiation


Aggregating environmental data in post-Fukushima Japan and beyond.

By Momoko Ito Foundation

Project URL:
Project Twitter: @safecast

Organisation URL:

  • Environment & Sustainability
  • Data
  • Geolocation
  • Physical Computing

Safecast was a small group of technologists’ response to the 2011 earthquake and tsunami that hit Japan, and the resulting radiation leaks from its nuclear reactors at Fukushima.

Public concern about the levels and geographical reach of radiation ran at fever-pitch in the immediate aftermath of the disaster. However official data from government and nuclear industry was at worst nonexistent, at best incomplete.

A very small transnational core team sprang into action: in under a week managing to mobilise their networks and resources to improvise a way to plug the information gap.

Faced with a worldwide shortage of commercial monitors the team wired together homemade Geiger counters out of readily available components. They fitted these with GPS, wifi and circuitry to output readings onto a laptop; then strapped them, with Nylon, onto a car that volunteers would drive through affected areas, logging measurements on the move in order to build a real-time picture of radiation levels, which were plotted in real-time onto maps.

This allowed the team, and members of the public, to monitor contamination across a broad area without needing a permanent network of stationary monitors. "[We] take radiation readings the way Google street view takes photos," as founder Pieter Franken describes it.

The group was funded through Kickstarter, and a few private donations, and quickly recruited hundreds of volunteers. With 800 sensors and 24m data points collected, Safecast has now published more measurements than any other organization in the field.

Joi Ito, one of Safecast's founders and head of MIT Media Lab, says 'It's an example of a global, agile network of experts self-organising to converge on a problem via the Internet to provide a rapid, open and very sophisticated response to an emergency… [data journalism] and the study of health effects is essential and [this data will] provide a strong based upon which we should continue to build."

While the non-profit's activities continue to focus on mapping in Japan, its long term vision is to put the collection and control of information in the hands of citizens worldwide: to build a radiation ‘baseline’ for the planet and to chart levels of environmental contaminants as well as radiation. 

Image - Safecast nano build event,  Sean Bonner

Last updated: 12th of May, 2014

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