Radioactive element radium-226 is responsible for radiation hotspots in Tokyo, not the Fukushima Daiichi reactor, according to experts.

Local officials, on Thursday, reported that although the Setagaya ward is actually very near the Fukushima reactor, radiation levels (which saw a spike recently) were caused by bottles of radium-226 stored in a wooden house in Tsurumaki 5-chrome.

As published in the official blog of Setagaya Ward Mayor Nobuto Hosaka, the investigating team with the resident's permission entered the house and found one spot with high radiation level. We The investigating team, according to the official blog of Mayor Nobuto Hosaka, of the Setagaya ward, entered the building (with the resident's permission) and found one spot with particularly high levels and later confirmed that the radiation appeared to be coming from what seemed to be bottles inside a cardboard box underneath the floor.

According to experts, residents of the house - a 90-year-old lady and her daughter - were exposed to the radiation levels approximately 30 times above permissible limits. The residents, however, are clueless about how the bottles containing radium got under the floors of their house.

Radium-226 is silver-white colored alkaline-earth metal that contains natural radioactive energy. High-level and long-term exposure to this can result in serious health complications and even death, according to researchers.

Radiation was not only found in Setagaya but also Yokohama and Funabashi (south and north of Tokyo, respectively), where researchers detected very high levels of radiation.

In a report released on Friday, the International Atomic Energy Agency (IAEA), after evaluating Japan's remediation-related strategies, plans and works, including contamination mapping of the areas located near to Fukushima Daiichi, urged Japan to tackle the present radioactive contamination condition in a more focused and practical way. The Mission Team consisted of 12 international experts.

The team has provided a comprehensive picture of the present situation and has advised Japan to initiate future full-scale remediation activities.