Much of this increase can be attributed to increased enforcement efforts in Thailand, disruption of the trafficking organizations in Burma, and China's limited drug interdiction resources. Improved transportation and communication links, a goal of China's economic development, facilitate the movement of narcotics as well as legitimate goods. Furthermore, China's political decentralization over the past 17 years has helped trafficking organizations increase their influence, as local governments may be less responsive to central law enforcement directives. Burma is the source of an estimated 90 percent of the heroin transiting China. Most of the illicit drugs shipped through China are transported across the border via vehicles and pedestrians.
Authorities believe that most drugs are then moved within China by motor vehicle.
Officials recognize that rail and air transport of drugs could become significant problems in the future, but state that these methods are still uncommon. There is little evidence of domestic production of heroin in China, but PRC officials say about 10 percent of the opium seized in China is produced locally. The PRC is a major chemical producer and exporter, and drug traffickers' attempts to acquire precursor chemicals are a growing problem for Chinese law enforcement officials. Although Chinese authorities have uncovered few cases of money laundering, the problem could increase along with a rise in drug trafficking and other illegal activity. Most drug addicts are 18-35 year old males.