It seems 2018 was the year of lettuce recalls . E. coli outbreaks rocked grocery store shelves, salad joints and refrigerators in the spring and then again in the fall .

Lettuce romaine calm , the pun nerds announced. Marked safe from romaine lettuce , joked the Facebook memes. If you really think the media is fake news, now is your chance to prove it: eat all the lettuce, laughed folks on Twitter .

And now that the government shutdown has postponed many of the FDAs food inspections , were more in the dark than ever.

In the grand scheme of foodborne illness outbreaks, why is lettuce the dirtiest vegetable? Well, it isnt it just seemed like that this past year.

We dont know if lettuce really is more susceptible to food safety issues than other products, said Paula Rivadeneira, an assistant professor and extension specialist in food safety and wildlife at the University of Arizona Cooperative Extension in Yuma, Arizona.

Yuma grows 90 percent of the lettuce eaten in the United States during winter and was singled out as where the lettuce in the spring 2018 recall had come from. (Falls recall was from California .) It was the Yuma lettuce industrys first foodborne illness outbreak, in part because of the hard work people like Rivadeneira put into protecting our food supplies. In fact, she told HuffPost, We dont know if lettuce really is more susceptible to food safety issues than other products or if we are just getting better at detecting it.

Recalls and food safety alerts come out in industry news almost daily, Rivadeneira explained, but most dont surface to the wider public. They run the whole gamut of fresh produce, meat and dairy.

There will never be zero risk when it comes to food that is grown naturally, she explained. These products are grown outside in the open air with open water sources and nature all around. This is true of plenty of other vegetables, too, but the nature of lettuce consumption brings it a lot of media attention: Not only is it eaten raw but its eaten very often.

The farmers do what they can, even testing for pathogens before harvest. But, with the way our food system works, a lot of people have to touch the produce before it gets to your kitchen: It gets washed, processed, bagged, transported, handled and moved in and out of a number of locations. There are a lot of places along that chain where contamination could happen, she admitted.

Lettuce, of course, seems significant, in part because of how much we eat lettuce is a $1.5 billion industry and the U.S. produced more than 7.6 billion pounds in 2017. But it also affects us because we eat it raw, so there often isnt an opportunity to cook out the pathogens.