As U.S.-grown marijuana displaces Mexican cannabis in this country, drug traffickers are sending more cheap heroin and methamphetamine into the United States, according to The Washington Post.
The amount of marijuana seized by U.S. officers along the Mexican border has decreased 37 percent since 2011.
In the past few years, American marijuana users have been choosing more potent, higher-grade varieties grown in the United States.
As the popularity of Mexican marijuana decreases, Mexican drug farmers are planting more opium poppies. The heroin these plants produce is being channeled to the U.S. communities hardest hit by prescription drug abuse, offering a cheaper alternative.
"Legalization of marijuana for recreational use has given U.S. consumers access to high-quality marijuana, with genetically improved strains, grown in greenhouses," said Raul Benitez-Manaut of Mexico's National Autonomous University. "That's why the Mexican cartels are switching to heroin and meth."
Last year, U.S. law enforcement agents seized 2,181 kilograms of heroin coming from Mexico, almost triple the amount confiscated in 2009, the article notes.
Methamphetamine seizures by U.S. Customs and Border Protection agents surged in 2014. A crackdown on meth ingredients in the United States has pushed the drug's manufacture to Mexico. The agency said there has been a 300 percent increase in meth seizures at California entry points from 2009 to 2014.
"The days of the large-scale U.S. meth labs are pretty much gone, given how much the Mexicans have taken over production south of the border and distribution into the United States," said Lawrence Payne, a spokesman for the Drug Enforcement Administration. "Their product is far superior, cheaper and more pure."
Sidney Aki of U.S. Customs and Border Protection noted, "Criminal organizations are no longer going for bulk marijuana. Hard drugs are the growing trend, and they're profitable in small amounts."