Potent white heroin from Afghanistan is pouring into the California illicit-drug market, supplanting weaker brown heroin from Mexico and raising fears of increased addiction and overdose problems, the Los Angeles Times reported Dec. 26.

"The rise of heroin from Afghanistan is our biggest rising threat in the fight against narcotics," said Jim Amormino, a spokesperson for the Orange County sheriff's office. "We are seeing more seizures and more overdoses."

A U.S. Drug Enforcement Administration (DEA) report said that the presence of Afghan heroin has risen rapidly in the U.S. market, rising from 7 percent in 2001 to 14 percent in 2004. Poppy production in Afghanistan has also skyrocketed since the U.S. overthrew the Taliban regime in 2001. The DEA said that Afghan heroin is the purest in the world.

In spite of these statistics, however, a DEA spokesperson insisted in an e-mail that, "We are not seeing a nationwide spike in Afghanistan-based heroin."

California addiction experts are warning local addicts to cut back on the amount of heroin they use to avoid overdosing on the potent Afghan heroin. "I tell people, 'If you're using it, only use half or three-quarters of what you used to,' because of the higher potency," said Orlando Ward, director of public affairs at Los Angeles' Midnight Mission.

Afghanistan provided about half of the heroin in the U.S. in the mid-1980s, but its share dropped in the 1990s as more of the drug was produced in Asia and the Taliban cracked down on poppy production in Afghanistan. Today, the Afghan opium crop is worth an estimated $2.3 billion, and more U.S.-bound heroin is being seized on flights from India, a major transshipment point for drugs smuggled out of Afghanistan.

The "China white" heroin produced in Afghanistan is pure enough that it can be snorted or smoked, making it more appealing to young and novice users, experts say.