In response to concerns about the radioactivity released by the Fukushima Daiichi nuclear disaster in 2011, and to remedy what he described as "confusing" reporting on radiation levels in the media, Munroe created a radiation chart of comparative radiation exposure levels. The chart was rapidly adopted by print and online journalists in several countries, including being linked to by online writers for "The Guardian", and "The New York Times". As a result of requests for permission to reprint the chart and to translate it into Japanese, Munroe placed it in the public domain, but requested that his non-expert status should be clearly stated in any reprinting.