U.S. food imports from China have more than tripled in value since 2001, according to a new report from the USDA’s Economic Research Service. Addressing safety risks associated with these imports is difficult, the report notes, because of the vast array of products from China, the country’s weak enforcement of food-safety standards, its heavy use of agricultural chemicals and its considerable environmental pollution. FDA refusals of food shipments from China suggest recurring problems with “filth,” unsafe additives, labeling (typically introduced in food processing and handling), and veterinary drug residues in fish and shellfish (introduced at the farm). Chinese authorities try to control food-export safety by certifying exporters and the farms that supply them. However, monitoring such a wide range of products for the different hazards that can arise at varying points in the supply chain is a difficult challenge for Chinese and U.S. officials.