U.S. law enforcement officials seized enough fentanyl to kill 229 million American in the six largest fentanyl busts in U.S. history combined, Fox News reports Wednesday.

Sara A. Carter produced a documentary Not in Vein in 2018 to expose the dangers the Mexican drug cartels pose with their vast fentanyl-trafficking networks.

Since then, she’s advocated for the U.S. State Department to designate the cartels “Foreign Terrorist Organizations.” Click here to watch the film.

Fentanyl is a highly-potent, synthetic opioid that’s fueled the opioid epidemic in this country. It only takes the equivalent of four grains of salt of fentanyl to kill the average adult.

Click here to read the full story on FoxNews.com.