Recent headlines are enough to give people pause before plunging off the diving board - Deadly Cryptosporidium Parasite Thrives in Pools; Parasite Found in Pools Could Be Fatal; Terrifying Facts to Make You Think Twice Before Swimming in Public Pools. According to the Centers for Disease Control, the number of cases of swimmer's diarrhea has doubled since 2004, due to the spread of the bacteria Cryptosporidium (1).
Before the 1970s, Cryptosporidium infections were only found in animals, and until the early 1990s Crypto was only a threat to people with severely weakened immune systems. But in 2012, over 8,000 people were sickened by Cryptosporidium (2).
So what changed? Factory farming.
The first known major outbreak of Cryptosporidium occurred in Milwaukee in 1993, when over 400,000 people were sickened and 100 killed by the parasitic infection. The Crypto was being spread through public drinking water that was contaminated with runoff from nearby dairy farms (3).
Since then, factory farms have only continued to grow. A recent Food and Water Watch report revealed that the number of dairy cows on factory farms doubled between 1997 and 2012, and the trend extends across all animal product industries (4). As the number of animals on factory farms grows, so does the amount of manure they produce.
Animals on factory farms produce enough waste in a single day to fill the Empire State Building (5). What happens to this waste? As you can see in this shocking drone footage, much of it is sprayed onto surrounding land, where it seeps into local water tables and runs off into local rivers. Studies have found that anywhere from 1/4 to 1/2 of this manure is infected with Cryptosporidium (6).
Most of the media coverage of the recent explosion in Cryptosporidium infections deals with the immediate source - swimming in pools contaminated with human fecal matter. Yet they are not asking a critical question - why is so much human fecal matter now contaminated by Cryptosporidium? As unseemly as it is, children have been relieving themselves in pools since the advent of swimming. The true source of the parasite is not people; it is factory farms.
While there have not yet been any scientific studies researching the source of the parasite in recent outbreaks, there is little doubt as to the connection between what was previously an animal-borne disease, the explosion of factory farming and water pollution, and the current spread of Cryptosporidium.