Contact with untreated sewage is, to put it mildly, unpleasant. But there are real and significant health effects as well. To find out more, I asked Dr. Joan Rose, Microbiologist and the Homer Nowlin Chair in Water Research at Michigan State University a few questions.

Dr. Joan RoseQ: What are the most pressing or worrisome health effects related to sewage in our waters?

A: We have heard a lot about norovirus outbreaks, flus and other "emerging diseases." Most of these pathogens end up in our sewage. We are exposing ourselves to all of these bacteria, viruses and parasites, spreading diseases "downstream" when we do not pay attention to treatment. New pathogens are evolving, some of our traditional pathogens [like] "cholera" are no longer an issue, but cancer causing viruses and bacteria have become known.

Therefore sewage treatment facilities are one of the most important systems that we have in place to protect public health. No where else in the world has a country paid so much attention to sewage. This great infrastructure that has provided US citizens with clean and healthy waters is at risk.

We have more people and we should be looking at all treatment facilities, [and how often facilities have to operate past] their design capacity .... .... we have failed to provide the wastewater industry with new tools to address ... new emerging microbial contaminants. And we have failed to upgrade our treatment facilities.

Q: Do we have a good sense here in the U.S. of how many illnesses are caused by sewage pollution?

A: We do not know. We know which illnesses are spread through a "fecal-oral" route, as mentioned before these pathogens end up in sewage. How many "downstream" illnesses occur is not known. It is interesting because by characterizing what is in sewage we can take a look into our communities (who is infected? Who is excreting pathogens? Are new pathogens emerging?) But no one does that. If we are going to be investing in our sewage treatment infrastructure, why not make sure we are improving things from where we are today?

Q: There's a lot in the news about pharmaceuticals and intersex fish - what's the relationship to sewage discharges and is there cause for concern?

A: We use medicines in our daily lives to treat illnesses and keep us healthy. These are excreted into sewage and sometimes people dump old medicines down the toilet. While the concentrations in water are well below what we take in "pill" form, there is concern that low levels of some of these pharmaceuticals might affect children or other special populations who should not be exposed to some of these drugs. But finally, people may not be affected as much as the animals that we share our world and our water with. Fish in particular because they live in our waters can be affected and we could easily lose population of important fisheries. Sewage treatment can remove most of these and that is something we can invest our efforts in.