A study by Tohoku University says  homes are traps for radiation contamination.

Radiation expert, Hiroko Yoshida, led the study. Since September they’ve monitored radiation exposure levels of 125 people in 31 households in southern Miyagi Prefecture.

They concluded that decontaminating the inside of houses would be the most effective way to reduce radiation exposure, because the interiors of houses accumulate radiation contamination.

Yoshida is urging local governments to start radiation decontamination in homes rather than in public buildings, since most people, especially children (who’re most vulnerable to radiation), spend more time at home.