The Food Control Office at Man Kam To is Hong Kong's first line of defence against any pestilence brewing across the border between China's newest special administrative region and Guangdong province. Each day, about 400 trucks roar up to the station's loading docks, where dozens of health inspectors swarm over the 900 tonnes of vegetables, fresh milk and live chickens headed for the city's wholesale markets. Tests are conducted and tonnes of contaminated produce destroyed all part of Hong Kong's struggle to stem the flow of tainted foods to its markets.