03/05/2014 11:23 am ET Updated Mar 05, 2014

Lab Animal Disposal System Raises Eyebrows In Hawaii

Steven Taylor via Getty Images

Plenty of attention is given to the treatment of live laboratory animals, but how about dead ones?

The University of Hawaii is raising a few eyebrows after a local news station reported that hundreds of pounds of dead lab mice are cooked, liquified and then dumped into the city of Honolulu's sewage system each year.

The process is relatively standard (and USDA approved) and great pains are taken to ensure its safety, but the imagery and -- for lack of a better word -- creepiness of it has the Aloha state in a bit of a tizzy.

The dead rodents, many of which have been infected with cancers or diseases like dengue fever or the West Nile virus, are put through a lengthy, neutralizing process. They are first frozen, then sterilized with chemicals, and then put in a tissue digester system (imagine a huge pressure cooker) for six hours, which turns the tissue into a "soupy liquid." From there, the liquid is dumped into the sewers.

To the lay person, this is a disgusting and disturbing thought and perhaps the beginning of a bad horror movie. Won't the pathogens and viruses lead to a public health risk? Can't we just cremate them?

Tissue digester systems, it turns out, are a safer, more environmentally friendly and a much cheaper option than incinerators. Designed specifically to neutralize pathogens, they use a combination of high heat (482 degrees Fahrenheit), pressure and a water solution of alkali metal hydroxides to break down tissue cells (including infectious microorganisms) into peptides, amino acids, sugars and soaps. According to Talia Ogliore, a University of Hawaii spokeswoman, the system "breaks down and destroys both the RNA and DNA of viruses."

As a bonus, since the systems are fully contained, nothing is released into the atmosphere and the resulting sludge, while pretty gross to imagine, is sterile even before it is processed again at the city's wastewater treatment facility.

In other words, the "soupy liquid" of infected research mice is one of the least hazardous materials we put into the sewer system every day.



Animals In The News