Salem's "10-days-until-you-get-sick" water advisory wasn't settled science

The folks at City Hall who made the indefensible decision to keep Salem residents in the dark for seven days after s sample was taken that showed high levels of a cyanotoxin in the water supply are trying to claim that a "10-day window" rule permitted this. 

In a Statesman Journal story, Public Works Director Peter Fernandez said:

City officials “hung our hat” on EPA guidelines that allow for a 10-day period to make treatment adjustments to fix the water. After 10 days, the buildup of toxins becomes more serious.

So let's take a look at how the 10-day EPA guideline was developed. It sure wasn't based on settled science, not even close. An EPA document, "2015 Drinking Water Health Advisories for Two Cyanobacterial Toxins." tells the tale.


First, the document says what Health Advisory (HA) values are, which implies what they aren't: objective facts that can be taken as solid science. Note the words "non-regulatory" and "informal."

HAs are non-regulatory values that serve as informal technical guidance to assist federal, state and local officials, and managers of public or community water systems to protect public health from contaminants.

l'm going to focus on the Health Advisory values for Cylindrospermopsin, the toxin that was first observed in the Salem water supply from a sample taken on Wednesday, May 23.

As shown below, the test result showed values almost ten times higher than the Health Advisory limit for vulnerable populations (children under six, pregnant women, others with compromised immune systems) and more than double the limit for the general adult population.

Now, those Health Advisory numbers look marvelously exact: 0.7 and 3.

So let's take a look at how they were derived. A supporting EPA document, "Drinking Water Health Advisory for the Cyanobacterial Toxin Cylindrospermopsin" explains that a single 2002 study on mice is the basis for the Health Advisory values.

Regarding humans, it is known that the cyanotoxin has nasty health effects, but it isn't known what level of the toxin produces those effects. (I've boldfaced that sentence.)

The main source of information on the toxicity of cylindrospermopsin in humans is from qualitative reports of a hepatoenteritis-like illness attributed to acute or short-term consumption of drinking water containing C. raciborskii. Symptoms reported include fever, headache, vomiting, bloody diarrhea, hepatomegaly, and kidney damage with loss of water, electrolytes and protein. No reliable data are available on the exposure levels of cylindrospermopsin that induced these effects.

Thus the Health Advisory values for a 10-day window, during which supposedly no ill effects from drinking water containing cylindrospermopsin will occur, which City officials "hung their hat on" (meaning, depended on), comes from a single study of mice, not people.

 

The first EPA document I mentioned describes what adjustments to the mice results were made so as to apply them to humans.

A 10-fold "uncertainty factor" was applied because mice are different from people. Another 10-fold uncertainty factor was applied because humans differ from other humans in how they react to toxins. And a 3-fold uncertainty factor was applied because of database deficiencies.

Combined, that resulted in a total uncertainty factor of 300 (10 times 10 times 3).

Remember: the values of .7 and 3 that resulted by applying that uncertainty factor derived from a single mouse study to humans is just a guideline. The EPA stressed that it is simply informal technical guidance for people such as City of Salem officials needing to decide whether to issue a public alert after high cylindrospermopsin levels were found in a water supply.

Obviously those values are neither solid science, nor settled science.

The uncertainty factors clearly are guesstimates. Are mice really exactly 10 times different from people? Are people really exactly 10 times different from other people? And most worrisome, is what is not known about cylindrospermopsin really three times greater than what is now known?

What if "database deficiencies" actually are much greater? Then the Health Advisory levels should have been much lower. But since no one knows what isn't known about cylindrospermopsin's toxic effects on humans, there's no way to be sure.

Bottom line: Officials with the City of Salem engaged in bureaucratic malpractice when they failed to alert the public about high levels of cyanotoxins in the drinking water when this was first known on May 26. Staff from the Oregon Health Authority didn't express an opinion on whether a health alert should have been issued, because this was up to City officials.

To name names, it was City Manager Steve Powers and Public Works Director Peter Fernandez who bore the responsibility to alert the public that high levels of toxins were found in the Salem water supply.

They failed in that responsibility. Alice Harman put it nicely on Facebook. There is NO 10-days-to-tell-us-about-it rule.

 

 

Lastly, the effect of cyanotoxins in the water supply on animals surely was significant, as most pets are considerably smaller than most people. Here's what someone concerned about their dog said in a letter to the editor in the Statesman Journal.

Just a short note to add to the outrage felt by Salem water customers with regard to the late notice (of contamination). 

While by no means anywhere near as important as the possible or potential vulnerability of Salem residents on chemotherapy and those with compromised immune systems, we, too, feel disgruntled by the very late notice. 

Our dog was diagnosed with bone cancer, has had her shoulder and leg amputated, and since February has had six chemotherapy treatments. 

Obviously, her immune system is compromised.  In fact, she cannot receive needed vaccines at this time. She began having diarrhea on Sunday or Monday of this week, (but) since receiving the notice and (our starting to use) bottled water - zero incidents! 

(Is there) further damage - who knows? 

B. Weyand
Salem