Public Comments on NIOSH Draft Intelligence on Carcinogen Classification and Target Risk Level Policy for Chemical Hazards in the Workplace

By Anna E. Mazzucco, Ph.D.

December 16, 2013

Thank you for the opportunity to speak today.  My name is Dr. Anna Mazzucco, and I speak on behalf of the National Research Center for Women & Families, and our Cancer Prevention and Treatment Fund.  After completing my Ph.D. in cell and developmental biology at Harvard Medical School, I conducted research at the National Cancer Institute.  I speak today as a cancer biologist gravely concerned that these regulations lag behind the state of the science, and fall far short of protecting Americans from occupational causes of cancer.

In 2013, more than half a million Americans will die from cancer.  A 2003 joint report from the National Cancer Institute and the National Institute for Environmental Health Sciences stated that “exposure to a wide variety of natural and man-made substances in the environment accounts for at least two-thirds of all the cases of cancer in the United States.” Yet after reviewing the current state of regulatory policy and research efforts, the President’s Cancer Panel reported in 2010 that “environmental health, including cancer risk, has been largely excluded from overall national policy on protecting and improving the health of Americans.”   When notorious and decades-known carcinogens such as asbestos and radon are still present at unsafe or unknown levels in American workplaces, how can the public have confidence that our regulations can handle new and complex occupational hazards arising every day?  Only a few hundred out of more than 80,000 chemicals in use in the United States have been tested for safety.  We should be concerned.

The National Institutes of Health estimated the total cost of cancer in 2008 at $201.5 billion in both direct health care costs and the indirect cost of lost productivity due to premature deaths.   Another recent study estimated that cancer is responsible for 20 percent of all health care spending.  Disability days alone cost $7.5 billion in lost productivity each year.  And these numbers cannot attempt to capture the human value of lives lost.

Unfortunately, the NIOSH draft report represents a continuation of the status quo.  It reinforces a reactive rather than proactive approach to regulation.  It maintains historical policy positions which are no longer appropriate.  It  places burdens on workers rather than on industry.  And, it overlooks glaring gaps in regulation. This report does not provide sufficient information on proposed new policies that would add to redundancy between agencies, rather than eliminating redundancy.  Even more troubling, these new policies could allow a more permissive stance towards carcinogens in the workplace despite more stringent regulation of the very same agents by other federal agencies.

We have 5 Areas of concern that we want to emphasize:

  1. Safe exposure limits must be based on actual, not theoretical, workplace exposures.  Real-life workplace chemical use involves multiple agents and complex exposures.  This report does not give any concrete statements on how to address the true chemical milieu to which workers are exposed.  There is no scientific reason to limit our safety analyses to single agents.  If the goal is to prevent chemical hazard exposure in the workplace, then we must start with the workplace, and not a theoretical framework which likely applies to very few real-life situations.
  2. Acceptable occupational risk assessments should be based on up-to-date, circumspect and truly representative information.  NIOSH uses a lifetime cancer risk increase of 1 in 1,000 as the acceptable regulatory threshold, while stating that “controlling exposure to lower concentrations is always warranted.” NIOSH admits that “an excess risk of 1 in 1,000 is one or more orders of magnitude higher than what the United States permits for the general public.” NIOSH justifies this questionable threshold with two arguments:  The first is the historic “benzene decision” made by the U.S. Supreme Court in 1980, where a 1 in 1,000 risk was used in a seemingly rhetorical example.  The second justification is that workers are a very small subset of the general population, and higher exposures for small numbers of people may be considered acceptable if they are comparable to the overall risks of employment itself.  We disagree with these nonscientific justifications.  There is increasing evidence that occupational carcinogens spread into the greater environment.  For example, trichloroethylene (TCE), an industrial solvent, is now present in approximately one-third of the U.S. water supply.   The maximum risk threshold acceptable to the EPA is 10-fold less than the NIOSH threshold – and given the overlapping exposures, that does not make sense.  The EPA considers 1 in 1,000,000 to be the target threshold for as many people as possible, but that is 1000 times lower than the NIOSH threshold. The bottom line is that there is no scientific basis for these differential safety standards, and we now know that occupational and environmental exposures frequently become indistinguishable.  For that reason, the workforce should be afforded the same level of protection as the general public.
  3. Safety determinations will only be as effective as the quality of the science they are based on.  This report outlines the use of linear modeling to extrapolate low-dose effects of carcinogens.  But linear modeling isn’t appropriate for chemicals with non-monotonic dose-response curves, such as endocrine disruptors.  In addition, bioaccumulation and multigenerational effects must be considered — otherwise, limits will be simplistic and inaccurate. When NTP/EPA/IARC classifications disagree, NIOSH says they will “adopt the classification determined to be most relevant to occupational exposures“.  This policy would allow for “down-classifying” of carcinogens based on workplace considerations.  Given the technical difficulty in distinguishing between occupational and greater environmental exposures, the public needs detailed information about this decision-making process, so that we can ensure that any down-classifications are justified by scientific evidence.  NIOSH should also consider making full use of the NTP Executive Committee before investing their own time and resources in classifying agents, in order to focus their efforts on the stated goal of reducing risks.
  4. A safe exposure level based on technical feasibility rather than safety places workers at risk. NIOSH plans to set the recommended exposure limit (REL) to the higher, detectable dose (the reliable quantitation limit).   This would directly place workers in potentially unsafe conditions, while rendering them powerless to detect or remove the agent to ensure safe levels.  If we want to instead guarantee safety to workers in this situation, NIOSH needs to ban these chemicals until more sensitive detection methods are developed.  That policy would protect workers while creating an incentive for industry to develop more sensitive diagnostic capabilities or find safer alternatives.
  5. Sensitive subpopulations require protections too.  Birth defects, childhood cancer, and adult cancers can all caused by in utero exposures.  The NIOSH draft report does not provide details on how sensitive subpopulations will be protected.  Just as NIOSH sets risk thresholds for all workers, it must have regulations which sufficiently protect everyone in that group.

We urge you to consider these changes, and use every resource at your disposal to ensure that our national policies regarding occupational carcinogens meet their goal of protecting Americans at work.  This will ensure a healthy society, thriving economy, and also safeguard our environment for generations to come.

For more information, contact Anna Mazzucco at (202) 223-4000 or