The Food Control Office at Man Kam To is Hong Kong's first line of defence against any pestilence brewing across the Chinese border. Each day, about 400 trucks come to the station's loading docks, where dozens of health inspectors swarm over the 1,000 tons of vegetables, fresh milk and live chickens headed for the city's wholesale markets. Tests are conducted and tons of contaminated produce destroyed, all part of Hong Kong's struggle to stem the flow of tainted foods to its markets.