More often than not, E. coli outbreaks in lettuce, spinach, and other leafy greens are sourced back to a field-grown operation in Arizona or California; two regions that, combined, grow 98% (!) of the lettuces consumed in the U.S. Inherently, these fields are susceptible to the risks of contamination from animals pooping in a field (probably while munching on some salad), polluted irrigation water (also probably caused by animals – dead or defecating), and poorly enforced sanitation practices.
Even if just one lettuce plant is contaminated, the chance that other lettuces get contaminated is very high. Not only are the lettuces comingled into a single box or container in the field, but they then follow a long and diluted chain of custody route from the farm to the packing shed, off to regional distribution centers, and then trucked to grocery stores and markets, all before it ever lands on your dinner plate (and that was a condensed version). And in the case of packaged lettuce, like your favorite Caesars mix, those lettuces may have originated from 5 or more farms. That’s a hard bread crumb (or crouton) trail for the FDA to follow.
Enter Controlled Environment Agriculture, or CEA. This method of farming shelters crops from the outdoors by growing plants in greenhouses or buildings. The simplest term used – and almost lost to history – is “protected agriculture,” a term that is most appropriate in the discussion of food safety. By farming inside buildings – regardless of whether it’s made of glass, plastic, or concrete – the risk of animal contamination is all but eliminated. Risk of water pollution also practically evaporates to nothing; as typical hydroponic irrigation systems are built with filters and purification systems to remove any potential contaminants before water is delivered to the plants. Water is also delivered directly to the roots, rather than sprayed or flooded over a field; so even if the water was contaminated, it wouldn’t get on the parts we eat.
As for the chain of custody concerns, they practically disappear with CEA-grown crops. Most, if not all, of produce grown indoors is marketed under a single, specific brand, with little to no comingling of produce sourced from different locations. In fact, that would be a pretty challenging feat, considering the hyper-local market many of these farms serve. Not only do indoor and greenhouse growers brand their product, they also label where it’s grown to appeal to their local market. Indeed, during this most recent E. coli outbreak, indoor farms and greenhouses were the first lettuce producers crossed off the FDA’s list of possible offenders.
The current conversation around indoor food production is often overshadowed by the debate over energy use and whether or not it justifies the reduction in carbon footprint by eliminating long food miles. But the recent E. coli outbreak in Romaine lettuce has highlighted an often overlooked potential benefit of growing indoors: improved food safety. As consumers continue to eat more fresh produce, food safety is going to become a greater factor in their purchasing choices. And until deer or raccoons can figure out how to open doors or cut through plastic, greenhouses and vertical farms will stand as a reliable source of safe and healthy fresh produce.