20 million!

Growth of Safecast Dataset

A few days ago, Safecast reached another milestone: 20 million data points!

If you look at the  graph above, you’ll see that, starting from zero, it took us 7 months to collect the first million data points. Our first GPS-tagged data collection efforts in mid April 2011 used an Inspector/iPhone combo. By April 23 the first bGeigie was operational, and after a successful test in Tokyo that day was on the road in Fukushima the next. Three of these units, a design we now call the “bGeigie Classic,” were built. We soon were able to deploy more compact units: the bGeigie Mini (34 units) in June 2011, and the bGeigie Plus (36 units) in October 2011, right around the time we reached one million. We were able to reach 5 million data points a little over a year later, in Nov. 2012. By then several bGeigie Nano prototypes had been built and tested (the first one went to Chernobyl in August 2012), and as we got final versions into the hands of volunteers worldwide we were able to reach 10 million data points by June 2013. We’re buzzed it took us only a year to double that.

This success is entirely due of the efforts of our volunteers. There are currently about 400 Nanos out there (though we can’t really say how many of these are actually in use; we assume some are sitting unbuilt), and our API shows 567 users, 387 of whom have uploaded data. Almost 3/4 of the data has been collected by the 10 most active volunteers. We’d really like to give a big shout-out to GLC, who have bGeigies on the road in Japan constantly, and who have contributed a whopping 6 million data points. KM Aizu is another very active group of volunteers, who have uploaded 1.7 million. Of course we get a lift when we see very active volunteers like these, but it’s not a contest and all contributions are extremely welcome.


Our global coverage has steadily improved as well. Lionel Bergeret recently produced this map showing the breakdown by country. It shows that Japan accounts for approximately 75% of the data, which shouldn’t surprise anyone. The next highest percentage is from the US, with over 2 million data points, or about 13%. Our database currently includes data from 54 countries in all, including most of the countries of Europe, several in Africa, Asia, and the Middle East, and a bit from South America. We also have some good data from Antarctica

We’ve been steadily expanding our nGeigie fixed sensor network, and have several online in Japan and the US now (they’re included in our Tile Map; click on a green antenna icon and a time-based graph of recent data will be displayed). And we’ve been continuing the development of our air quality sensors (Safecast Air). We can’t stress enough how important openness has been to our success. Anyone can download our data and use it for whatever they want, no strings attached, our hardware and software designs are open-source and available for free use as well, and our iOS app is free. The bGeigie Nano kit costs money, but as this reviewer who sourced all the parts himself confirmed, it costs the same whether you buy the kit or hack it yourself.

In case anyone still has doubts, SAFECAST is in this for the long haul. The Fukushima disaster goosed everyone into action, but an increasing amount of our discussion is about long-term environmental monitoring needs, how to provide baseline coverage for as much of the globe as possible, how to communicate it all rapidly and effectively, and above all, how to get people working together on shared goals. SAFECAST has changed all of our lives, and success is a powerful motivator. But we’d still be doing it even if nobody was paying attention.


About the Author

Azby Brown

Azby Brown is Safecast's lead researcher and primary author of the Safecast Report. A widely published authority in the fields of design, architecture, and the environment, he has lived in Japan for over 30 years, and founded the KIT Future Design Institute in 2003. He joined Safecast in mid-2011, and frequently represents the group at international expert conferences.