On March 11, 2011, an 8.9 magnitude earthquake triggering a 30 ft tsunami struck the Pacific Coast of Japan. The force of the tsunami destroyed a great deal of the infrastructure along portions of the Japanese coast. The most notable damage from the tsunami has affected the Fukushima Daiichi nuclear plant. The following prefectures are in the closest proximity to the Fukushima Daiichi nuclear plant: Fukushima, Gunma Ibaraki, and Tochigi.
The Fukushima Daiichi nuclear plant houses several nuclear reactors that have posed signs of a potential threat of radiological contamination to the surrounding areas. Due to the public health concerns that are associated with radiation and nuclear contamination, FDA has increased surveillance of regulated products from Japan.
The following link outlines the FDA policy regarding Japanese food imports entering the U.S.
The import alert does not automatically keep products from entering the U.S., but does cause them to be automatically detained and tested for contamination. Additional updates are being issued by FDA as the need arises.