After feeling all smug and superior about eating vegan these last few months (meat recall here, meat recall there), wham! tomatoes are infected with Salmonella. I wasn't planning on writing a post on this topic because it's all over the place, but today, instead of more stories about who's not carrying tomatoes, and what variety is infected, I read an explanation as to why this is happening. So here is the executive summary of the article I read in New Scientist Magazine.
Bottom line, it appears our groundwater is contaminated with animal feces. The water is used to propogate the tomatoes which then act as an "incubator" for the Salmonella.
A recent census of produce outbreaks between 1996 and 2007 counted no fewer than 33 epidemics from Salmonella-contaminated fruits and vegetables. In five of them, tomatoes were the culprit. Cantaloupe melons and sprouted seeds, such as clover and alfalfa, were also common victims. Animal pathogens tend to infect only a limited range of plants.
Yikes! And yet another reason not to eat meat! (Less meat consumed = less production = less groundwater pollution.)
Scientists postulate that since fresh vegetables are increasingly packaged and shipped in centralized locations, nationwide epidemics are becoming more prevalent. Interestingly, "cleaner" produce isn't necessarily the solution either. Harmless bacteria coat tomatoes and other produce, and that could be killed off by more thorough washing. These bacteria compete against pathogens like Salmonella. One lab found that tomatoes coated with a harmless form of a bug called Enterobacter were less likely to test positive for Salmonella. Salmonella seems to like it when there's no competitor.
So, our groundwater is contaminated by animal feces, and our crops are being propagated with this polluted water. Well, if we're processing ten billion animals annually for food here in the US, that's a lot of poop to process! It certainly stands to reason that not all of that poop is being processed effectively. According to the UN Report, Livestock's Long Shadow (pages 140-142):
the most important water-borne bacterial and viral pathogens that are of primary importance to public health and veterinary public health are:
- Campylobacter SPP
- Escherichia Coli 0157:H7 (this is responsible for last year's spinach recall)
- Salmonella SPP*
- Clostridium botulinum
- Giardia lamblia
- Viral diseases (ie - foot and mouth, swine fever)
- Livestock Parasitic Diseases
- Cryptosporidium parvum
- Microsporidia SPP
- Fasciola SPP
* This is the variety of salmonella which is responsible for the current tomato recall. Salmonella spp is present in 41% of turkeys tested in California and 50% of chickens tested in Massachusetts.
The Sierra Club reports that factory farms produce 500 million tons of animal waste per year.
According to the Environmental Protection Agency, hog, chicken and cattle waste has polluted 35,000 miles of rivers in 22 states and contaminated groundwater in 17 states.
Clearly, we have a problem. If you'd like more information, Livestock's Long Shadow has in depth details on water pollution -- pages 144-162.