A US senator has called on the government to investigate the national security impact of Chinese garlic imports, arguing that Chinese garlic is dangerous, citing unsanitary production methods using human waste, reports BBC.

China is the world’s largest exporter of fresh and chilled garlic, and the US is the main consumer.

But the trade has been contentious for years, with the US accusing China of exporting garlic at dumped prices.

Since the mid-1990s, the US has imposed high tariffs or taxes on imports from China to prevent American manufacturers from being driven out of the market.

In 2019, during the Trump administration, these tariffs were increased.

Republican Senator Rick Scott wrote to the Commerce Secretary to draw attention to the issues and to highlight “serious public health concerns about the quality and safety of garlic grown in other countries, particularly garlic grown in Communist China.”

He’s referring to practices he says have been “well documented” in online videos, food blogs and documentaries, including growing garlic in human waste.

He asked the Commerce Department to take action under a law that allows it to investigate the impact of certain imports on US security.

He states, “Food insecurity is a life emergency that poses a serious threat to our national security, public health, and economic prosperity.”

The Office of Science and Society at McGill University in Quebec, which tries to promote and explain scientific issues, says there is “no evidence” that sewage is used as a fertilizer to grow garlic in China.

“In any case, there is no problem with this,” according to an article published by the university in 2017.

“Human excrement is as effective a fertilizer as animal excrement. Spreading human sewage onto crop fields sounds unappealing, but it’s safer than you think.”