Sunday, March 29, 2015

Hope and Change in Human Health Risk Assessment

Sarah Palin once mocked our President by asking him, “How’s that Hopey Changey think working out for you?”   It struck me that hope and change or, more specifically, the hope for positive change is, or should be, an important and positive human attribute.   Indeed, I see the opposite sentiment as resignation, stagnation and despair which really does not serve anyone well.

In the interest of full disclosure, I have to admit that  I am a hard core Pollyanna, whose Cambridge Online Dictionary definition is:  person who believes that good things are more likely to happen than bad things, even when this is very unlikely.   Indeed, I have been predicting that the general widespread acceptance and application of quantitative human health risk assessment will happen within the next two years for more than 25 years!   It has been argued that this has not happened to date as the vast majority of chemical exposures and risk are not well characterized.   See previous posts: 

  • We do not estimate Quantitative Risk for Most Chemicals (May 24, 2013)
  • Why Isn’t Risk Assessment Done on All Chemicals? (October 28, 2013)
  • Exposure Modeling Data Base Needs (August 8, 2014)
  • We do NOT spend enough on Risk Assessment (November 24, 2014)

I do want to point out some of the remarkable advances that have occurred over the last 25 years within the science and practical tools of human health exposure/ risk assessment.  From my perspective, most of them have come from volunteers within the committees of the  American Industrial Hygiene Association.  The Exposure Strategies and Modeling Books and the associated modeling software have been great advances on the exposure assessment side.   I think most of my colleagues, however, will agree that we could do a lot more given more resources. 
On the toxicity side of things the situation is much worse.  Except for a few promising exemptions (like EPA ToxCAST), it has remained stagnant for years as we do not have nearly enough exposure limits and necessary improvement in their documentation do not even appear to be on the horizon.

All of this is not to say that some companies and organization do not recognize the importance of doing the exposure or toxicity work to provide good assessment of chemical risk in order to do a rational and responsible job of managing the risk.    They have what I call “enlightened self-interest”;  they understand the importance and proper place of doing this as the “right thing to do” and in the long run “good business”.   Most of my clients fall into this category; however, I must tell you that I do not have many clients.   If you want some more insight into one aspect of this reality from someone with a lot more field experience than I do, check out the following post on this blog:

IH’s Dirty Little Secret (January 26, 2014)

Indeed, some companies and their organizations see their relationship with regulators as essentially adversarial, indeed, as covertly but un-apologetically war-like.    As a Risk Assessment Scientist working for a large chemical company in the 1970s through 2003, I participated in industry group meetings where I saw this attitude first-hand.  

Below is a small and edited excerpt from a letter I wrote to a staffer for such a group many years ago asking their advice:

“I believe that it is not accurate or useful to accuse or think of the regulators as not using science.  It implies that we own the scientific truth and I tell you that we do not.  We may have some more or less sophisticated scientific information that supports a less conservative regulation but our interpretation may not be compelling to the regulators who obviously have a different perspective.  More important, they own the risk management call.   It’s not that they do not use science but the reality is that they use “their” science and not “ours”.   We need to work on understanding their perspective and their standard of proof while gaining some common ground and building consensus.
Our science policy should be one of cooperation, understanding and bridging and not confrontation.  If the science that we developed is particularly well done then historically the difference between “their” science and “ours” should narrow.   There are a few examples of this but they all involved considerable expense to do the work that needed doing.”

The letter went on to seek advice from the staffer as to whether I should ever openly voice such an opinion and advocacy for change in policy and approach.    The response was that it would not be appreciated and I was advised to not give it voice.

That was almost 15 years ago and general opposition to practical and meaningful reform of the chemical regulatory process including the need for risk assessment in this country continues to receive serious opposition from groups speaking for the industry.

I believe that the industry in general would do so much better to broadly embrace enlightened self-interest and work for rational regulation and significant development of the science.   That remains my fervent hope but I am an admitted Pollyanna.   Indeed, it is entirely possible that the cold hand of regulation may be the only force that will ultimately catalyzes and provides real change and advancement in the science.


  1. Mike, I realise you have a US perspective but the REACH Programme in the EU is doing much on quantified risk assessment. Derived No Effect Levels (DNELs and Derived Minimum Effect Levels (DMELs) for all registered substances will provide Exposure Limit Values for a huge range of substances. Suppliers are now required to develop exposure models (Exposure Profiles) with a suite of control measures that will reduce exposure to below the DNEL. These are developed through the use of models such as ART. These will be communicated with end users through an extended Safety Data Sheet (eSDS). End users will be required to use the specified control measures as a minimum standard.

    Issued by ACRONYM Central :-)


  2. "Indeed, I have been predicting that the general widespread acceptance and application of quantitative human health risk assessment will happen within the next two years for more than 25 years!"

    Here's why it hasn't happened:

    Here is what I think needs to happen to fix it:

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