The study looked at mercury levels in soil and rice plants in Korea to ensure food safety. They found that the mercury levels in the soil were below contamination thresholds. The mercury levels in the polished rice were also below criteria set by other countries. The study showed that most of the mercury uptake in rice plants was in the rice straw, with less in the polished rice. Overall, the study concluded that mercury contamination in polished rice in Korea is not a major concern.