PFAS Compounds vs. Legionella -- Which is the bigger threat?

Posted on October 2, 2018 by Kenneth Gray

 

Recently, Per- and Poly-Fluoroalkyl Substance (PFAS) compounds have been dominating the national environmental news.  U.S. E.P.A. has named them as a priority for action.  In the several areas where the substances are found in groundwater, PFAS compounds dominate the local headlines.  The levels of detection and possible concern are extremely low, and the chemicals are almost ubiquitous in the environment, having been used for decades.  As manufactured chemicals, they suffer the usual popular and misguided presumption that they must therefore be bad, and there are manufacturers, industrial users, and water suppliers that have been the targets of anger and lawsuits. 

EPA’s national drinking water monitoring program for “unregulated contaminants” captured PFAS compounds several years ago, and significantly more testing is being undertaken. The former “emerging contaminants” have emerged with a vengeance.  https://bit.ly/2xnGi89  EPA soon will be providing additional guidance on risk levels for some PFAS compounds, and has recently committed to consider a national drinking water standard, among other possible regulatory actions.

Legionella pneumophila (Legionella) is a common bacteria that is found in nature, but can proliferate in certain human environments including hot water systems, shower heads and sinks, cooling towers, and hot tubs, among others, despite central treatment of drinking water.  Legionnaires Disease (LD) can and does kill, especially attacking those with weaker immune systems.  It is the most significant waterborne disease (about 60% of the outbreaks causing disease, and it is the only one causing death).  Data indicate that the disease is significantly on the rise around the country (only partly due to increased detection).   Where LD is discovered and results in illness and deaths, the disease has gotten significant press.  However, U.S. E.P.A. hasn’t yet called for national monitoring for Legionella, and there is no EPA-approved test method.  Although central treatment for bacteria and viruses is addressed in part by public water system disinfection, post-treatment testing and proliferation of Legionella hasn’t been formally addressed.

Scientists would agree that there are risks from PFAS compounds, but the toxicology is still developing and the most robust epidemiological data available do not indicate some of the risks suggested by some animal studies.  There is no such debate on Legionella – it is documented as a serious human health threat and has caused many deaths. The U.S.C.D.C. has indicated 90% of LD cases could have been prevented with better water safety management. While PFAS compounds can be tricky to test for and drinking water levels are being set in lower and lower parts per trillion, Legionella is easy and inexpensive to test for, and accurate, easy and cost-effective methods already exist.

Despite all this, PFAS compounds get more attention from media and regulators, and employ more laboratories and plaintiffs’ lawyers.  Like some current and former drinking water officials I know, I fear we are not focusing on the bigger health threat. 

Your thoughts? Let the informed debate begin.