Mexican farmers are producing more opium to feed a growing heroin addiction in the United States.

According to The Associated Press, the heroin trade is booming for Mexican cartels amidst a decline in cocaine consumption and marijuana legalization in the U.S. Mexican drug traffickers are using the same distribution routes they have built for marijuana and cocaine to push heroin.

Farmers say bricks of opium are the only thing that will guarantee them a cash income.

"Almost everyone thinks the people in these mountains are bad people, and that's not true," Humberto Nava Reyna, the head of the Supreme Council of the Towns of the Filo Mayor, told the AP.

The Supreme Council promotes development projects in the mountains.

"They can't stop planting poppies as long as there is demand, and the government doesn't provide any help," Nava Reyna said.

Residents say there are no local users of heroin, except a few who would rub the paste into their gums to sooth a toothache. All of the opium production goes for export through business ran by the Sinaloa Cartel.

Mexico produces nearly half of the heroin found in the U.S. Back in 2008, Mexico provided just 39 percent of the heroin found in America. 

The Mexican government has heightened its efforts in taking over opium and poppy plantations. Between 2013 and 2014, opium seizures were up 500 percent.

"The money the government spends on aerial spraying would better be spent on long-term development projects," Nava Reyna said.

The U.S. border also heightened its efforts of stopping the flow of the drug as well. 

Even with government officials crackdown on drug trafficking, Mexican heroin has become cheaper and more powerful. Pharmaceutical opiates add to the new wave of addictions and overdoses in the U.S.

Heroin deaths in America have doubled between 2011 and 2013.