Laundered Shop Towels: 1 - A mountain or mole hill of risk

I recently got back from attending the AHMP's 2011 National Conference in Austin Texas the end of August.  AHMP is an association for CHMMs, CETs, and EHS professionals.  I attended a bunch of well presented presentations, and also presented one myself on Wednesday.

I found myself on Tuesday attending a presentation by Crystal Leach, Ph.D, who is Director of Global Research & Engineering with Kimberly-Clark Professional, titled:

"Evaluation of Potential Exposure to Metals in Laundered Shop Towels"

Which is the basis behind this question posed to workers by Kimberly-Clark:

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Because of what was found, according to Kimberly-Clark:

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Those red and black bars paint a very dire picture for those workers using laundered shop towels.  So bad is the risk that Kimberly-Clark has a webpage called "the dirt on shop towels" to show workers how bad it is.  Heck there's Mike Rowe on the page holding laundered shop towels!  I'll have to check out what he has to say about all of this later on.  Right now I am interested in the brochure they developed with this ominous warning on the first page:

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The question that one should be asking is this: Should workers be concerned about their health if they are using laundered shop towels?  Should we believe Kimberly-Clark, who sells disposable shop wipes, when they inform the worker that "what they don't know" about laundered shop towels "could hurt them?"

Kimberly-Clark will tell you to believe them because:

"Two studies conducted during the last 8 years show that laundered shop towels contain toxic heavy metals even after laundering." (1)

It's not Kimberly-Clark saying this, it's based on two studies.  Independent studies performed by:

"an environmental and risk science consulting firm renowned for their expertise in Toxicology, epidemiology, Risk Assessment, Product Safety, Contaminant Fate and Transport, and Environmental/Forensic Chemistry." (1)

According to the abstract for the presentation by Crystal Leach, that firm, Gradient:

"undertook analysis of laundered shop towels, and concluded that, even after commercial laundering, the towels studied retain elevated levels of metals. Estimated metal intakes were compared to the California Environmental Protection Agency’s (CalEPA) Proposition 65 regulatory limits for cancer or reproductive effects as well as to various health-based criteria, including those from the U.S. Environmental Protection Agency (U.S. EPA) and the Agency for Toxic Substances and Disease Registry (ATSDR), a federal public health agency of the U.S. Department of Health and Human Services. The Gradient study finds that, for the worker using the typical amount of towels per day, average exposure to seven metals (antimony, beryllium, cadmium, cobalt, copper, lead, and molybdenum) may exceed health-based exposure guidelines set by these agencies. For example, based on the calculations discussed in the 2011 Gradient study, a worker may ingest up to 3,600 times more lead on a daily basis than recommended by CalEPA. Excessive metal exposure over time may present a health concern.

So armed with two studies, performed by a renowned company with expertise in such matters, Kimberly-Clark is able to claim that a worker using laundered shop towels may ingest  up to:

"3,600 times more lead on a daily basis than recommended by CalEPA,"  

Kimberly-Clark even provided us CHMMs with this graphic to show what and how it happens:

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That's pretty scary stuff.  I mean 3,600 times higher for lead...from a laundered (i.e. cleaned) shop towel?  Wow!

Now the question becomes: Should we believe the findings in the Gradient study that has been submitted for  publication in the International Nonwoven Journal for the Association of the Nonwovens Fabrics Industry (INBA).

Should we believe this study because it was produced by a renowned company with expertise in risk assessment?  Should we believe their findings because they do not "endorse Kimberly-Clark products or marketing materials?"

Gradient would most likely defend this work by pointing out the credentials of the three researchers who authored it.

Grace Greenberg MPH: I can't find any information on Ms. Greenberg, but she appears to hold a Masters in Public Health.

Barbara D. Beck PhD is an expert in toxicology and in health risk assessment for environmental chemicals, especially metals and air pollutants, and is the author of over 100 book chapters and journal articles on these topics. She has performed site-specific and chemical-specific risk assessments, developed exposure and risk assessment methodologies, and has presented the results to different audiences including regulatory agencies, the US Congress, and the public. Before joining Gradient, she was Chief of Air Toxics Staff for US EPA Region I. Prior to that she was a Fellow in the Interdisciplinary Programs in Health at the Harvard School of Public Health. She is at present a Visiting Scientist in the Molecular and Integrative Physiological Sciences Program in the Department of Environmental Health at the Harvard School of Public Health. (2)

Leslie A. Beyer MS is a senior project manager and toxicologist with over 20 years of experience. Her areas of expertise include environmental health, occupational health and safety, litigation support, project management, and risk assessment. Her projects have covered a variety of topics, including substantiation of structure-function claims for dietary supplements; historical toxicology of vinyl chloride, benzene, and lead; and review and interpretation of toxicological and epidemiological literature and data. She evaluates the significance of occupational and residential exposures, conducts health risk assessments for cancer and non-cancer endpoints, and assesses health effects from exposure to environmental chemicals. Ms. Beyer develops strategy and prepares expert reports in support of litigation cases involving product liability and chemical exposures (e.g., MTBE, dioxin, perchloroethylene, ozone, chromium). (3)

Wow...impressive.

So armed with all of this information I find myself at a crossroads.  Should we accept or reject the conclusion that Gradient has put forth?

Heavy metals have been found in laundered shop towels in amounts that exceed health-based exposure guidelines related to cancer and non-cancer related health issues, like reproductive and developmental effects.

Should we accept it based on the reputation of Gradient and the credentials of the three authors?  Or should we look deeper into the study to see how they came up with data that affords Kimberly-Clark the ability to ask workers:

Why risk it?  Who's counting on you?

Well I have looked into it.  I can support my conclusion that there is no additional risk to a worker using a laundered shop towel.  Period.  Should you believe me?  No, not until you read what I am putting forth as my reasons why this study is flawed and their conclusion false.

Are you sure you want to continue on with this endeavor Bowman?  I mean, we got a Harvard Ph.D and former Chief of Air Toxics for EPA Region 1 as one of the authors!  Are you sure about this?

Yeah...I'm sure.


Next Post: Laundered Shop Towels: A flaw in the model.