Sumitomo Osaka Cement Co will resume production at a Tochigi Prefecture factory that had been suspended due to radioactive contamination of cement-making materials. The plant in the city of Sano was shut down after radioactive cesium released from the crippled Fukushima Daiichi nuclear power facility was found in sewage sludge used to make cement. After testing cement produced and shipped after the earthquake disaster, the product was determined safe based on standards drawn up by the Land Ministry, according to the firm. Sumitomo Osaka Cement has decided not to use sludge from sewage treatment plants in Fukushima Prefecture for the time being. The ministry issued a notice to the governor of Fukushima regarding radiation detected in sludge from the prefecture’s multiple sewage treatment plants. Sludge that contains more than 1,00,000 becquerels of radioactive substances per kilogram must be sealed in containers and stored, but it can be used for cement production and other purposes if the contamination is not significant, the ministry said.