September 15, 2012 · 0 Comments
Viruses Creep Into Public Water Supplies Through Leaky Pipes
Sept. 14, 2012 — Two new studies are making waves in the tap vs. bottled water debate.
The first study shows that the pipes that ferry drinking water from public wells to home taps may let in viruses that cause more than a million cases of stomach illness every year. It’s published in Environmental Science & Technology.
The second study, in the journal Environmental Health Perspectives, shows that when viruses surge in tap water, people have a 30% higher risk of getting nasty stomach bugs that cause vomiting and diarrhea.
The studies stem from the same government-funded research project. It’s one of the largest ever to look at illnesses tied to public water supplies.
“As an individual looking at these results, I was alarmed,” says researcher Frank Loge, PhD, an environmental engineer at the University of California at Davis.
“The drinking water that we have in the U.S. is very, very good relative to other countries, and so I don’t want people to get the impression that we have a really bad problem relative to other parts of the world,” Loge tells WebMD.
“It really made me rethink whether I want to drink bottled water vs. tap water,” he says, noting that bottled water has its own problems. For one, it comes in plastic bottles that are often sent to landfills. Some bottled water comes from municipal water sources.
But some bottled water is bottled close to its source, and doesn’t travel through leaking pipes, which may ultimately render it cleaner.
Until more is known about bottled and tap water, Loge says, the question of which one is safer is still murky.
The project compared 14 public water systems in Wisconsin. Like more than 147,000 towns in the U.S., all the communities in the study pumped their public water from underground pools called aquifers. And like many of communities that rely on groundwater, the 14 in the study didn’t disinfect the water after it left those large wells.
For the first year, eight of the communities installed powerful ultraviolet (UV) lights to clean the water as soon as it left the underground pool. The other six continued to have no disinfection.
Scientists sampled water each month from the underground pool, from an area that was just past the UV disinfection, and then from six to eight home taps. The second year, the towns swapped. The eight towns that used UV disinfection turned their systems over to the six that didn’t have them. That let scientists compare how well the UV systems worked to clean the water.
After the two years of watching the water, researchers found that no community had consistently clean or consistently contaminated water.