Backyard Talk

It’s Time to Move Beyond Risk Assessment

Risk assessment is the standard method for evaluating exposure to toxic chemicals, despite the fact that it’s nearly impossible to do a risk assessment that is objective and accurate. There are just too many hard-to-measure factors affecting the chance that any one chemical will harm us and if so, how and to what extent, and too many ways for personal bias to change the results. For example, there’s been a long argument about whether arsenic causes cancer. We do know that it’s poisonous. It probably does cause cancer, but many people seem to be immune. So we’re not sure how many cases might occur, and what amount of arsenic might cause cancer. Also, it doesn’t seem to cause cancer in animals, so there’s no way to put the information together. When there are information gaps, the only thing we can do is build-in an extra safely factor, by making the “allowable” level a certain amount less than what we think the “safe” level is. But is that really the answer?

The public wants greater protection from exposure to toxic chemicals than provided by the traditional quantitative risk assessment approach which has many limitations and uncertainties. Instead, support has grown for use of a precautionary approach that promotes (1) preventive action, (2) democratic and transparent decision-making with the broadest possible public participation, and (3) a shifting of the questions being asked (e.g., instead of asking what level of risk is acceptable, asking how much risk can be avoided; what is the need; why is it needed; who benefits and who is harmed; and what are the alternatives?) as well as the presumptions used in decision-making (e.g., shifting the burden of proof to the proponents of potentially harmful activities, and placing public health above other considerations).

In its 2009 report, Science and Decisions, the National Resource Council (NRC) of the National Academies acknowledged that risk assessment is “at a crossroads” facing “a number of substantial challenges”, that “its credibility is being challenged”, and that the “regulatory risk assessment process is bogged down”.  The report made a number of recommendations that focused on improving the methodology of risk assessments (e.g., thorough evaluation of uncertainties and variability, unified dose-response approach to cancer and non-cancer endpoints, broadening the assessment of cumulative and interacting health risks and stressors), and improving the relevance or utility of risk assessments for decision-making (e.g., involving all stakeholders at the earliest stage of the planning, design and scoping of the risk assessment, and increasing the transparency of the assessment methods and process).

The NRC recommended two major shifts: (1) “that risk assessment should be viewed as a method for evaluating the relative merits of various options for managing risk”, with the risk management questions being “clearly posed, through careful evaluation of the options available to manage environmental problems at hand,” casting light on “a wider range of decision options than has traditionally been the case”; and (2) aligning closely the technical analysis with the problem at hand so that the risk assessment will be relevant to the needs of the decision-makers and stakeholders who are addressing the problem (e.g., a “one size fits all” approach to risk assessment will not be appropriate for such very different problems as regulating a chemical and deciding on a site remediation approach).

These recommendations are now more than 5 years old, and there’s little evidence that government is adopting these recommendations. Doing so should improve the ability to interpret hazards, contamination levels and population exposures, dose-response relationships, and cumulative risks (exposures from multiple pathways, complex mixtures, multiple stressors, and factors affecting vulnerability), as well as the evaluation of a wide range of alternative options (e.g., inherently safer technologies, alternative ways to achieve the same goal, etc.). It could also provide a way to integrate the risk assessment tool within a broader precautionary approach that seeks to reduce or avoid exposures to toxic chemicals, which the public is actively calling for. It’s time to stop accepting risk assessment as the best we can do to evaluate risks and adopt more a holistic approach to protecting public health and the environment.

Backyard Talk

For BPA, Does the Dose Make the Poison?

For those who keep up with environmental health research and chemical regulations, it is no surprise to come across conflicting reports on the safety or risk of various compounds. This week, in the case of the compound bisphenol A (BPA), these conflicting reports happened to emerge almost simultaneously. On January 21st, the European Food Safety Authority declared that BPA “poses no health risk to consumers of any age group…at current exposure levels.” The next day, a study published in the journal PLoS Genetics showed that even low and short-term exposures to BPA and other hormone-mimicking compounds could alter stem cells and lead to lower sperm counts.

BPA is a common ingredient in plastics used for food and drink containers. Its hormone-like properties allow it to disrupt the endocrine system, with potential health effects ranging from reproductive issues to cancer. Though BPA has been banned in baby bottles in the U.S., and BPA-free products have become widely available since concerns about the compound were first raised in 2008, it remains in products from water bottles to the inside coatings of cans.

[fusion_builder_container hundred_percent=”yes” overflow=”visible”][fusion_builder_row][fusion_builder_column type=”1_1″ background_position=”left top” background_color=”” border_size=”” border_color=”” border_style=”solid” spacing=”yes” background_image=”” background_repeat=”no-repeat” padding=”” margin_top=”0px” margin_bottom=”0px” class=”” id=”” animation_type=”” animation_speed=”0.3″ animation_direction=”left” hide_on_mobile=”no” center_content=”no” min_height=”none”]

David McNew via Getty Images

‘The dose makes the poison’ is a well-known adage in toxicology, implying that even hazardous chemicals can be harmless at low enough concentrations. However, decades of research have shown this to be an overly simplistic way of analyzing toxic exposures.  Dr. Theo Colborn, who passed away on December 14th, 2014, was a pioneering researcher in the field of endocrine disruption and a tireless advocate for precautionary chemical regulation. Her research on endocrine disruption demonstrated that even very low concentrations of harmful chemicals could result in changes to the reproductive system, particularly in developing babies and children who have less of a tolerance for exposure than adults. She also demonstrated that not all effects of toxic chemicals are immediately apparent, but can occur decades and even generations later.

The study published last week focused on both questions of concentration and timing. The researchers tested estrogenic compounds including BPA on mice, and found that they alter the stem cells, or undifferentiated cells, which are responsible for sperm production later in life. Patricia Hunt, the researcher who led the study, told Environmental Health News that exposure to even low doses of estrogens “is not simply affecting sperm being produced now, but impacting the stem cell population, and that will affect sperm produced throughout the lifetime.”

Uncertainties remain in the wake of this study. For instance, the researchers are still investigating whether the changes observed can cross generations, or whether the same changes can occur in human reproductive stem cells. The EFSA also recognized uncertainties in non-dietary sources of BPA, and they are still conducting long-term studies in rats. While scientists and regulators continue to chase answers, this past week shines a spotlight on the complicated realm of environmental health risk assessment, and shows the continued relevance of Dr. Theo Colborn’s work and legacy. Dose is indeed important in making a poison, but so is timing of exposure, and time itself in revealing the chronic and transgenerational effects of chemicals.


Backyard Talk

Grassroots Activism Makes the Difference in New York

Right before Christmas, the Washington Post ran an interesting article you may have missed. It laid out the conundrum of two states coming to very different conclusions about fracking within its boundaries. Both states, New York and Maryland, had moratoriums in place and were evaluating pretty much the same technical and scientific information, yet they came to very different conclusions.

In New York, Governor Andrew Cuomo chose to ban the practice of hydraulic fracturing or “fracking” in New York State. Fracking is the process of injecting a chemical/water mixture under extreme pressure deep into the earth in order to “fracture” rock and release natural gas (or oil). Cuomo’s decision followed a report from the New York Department of Health that found “significant public health risks” associated with fracking including concerns about water contamination and air pollution. In a press statement, the state health commissioner stated that there was “insufficient scientific evidence to affirm the safety of fracking.”

On the other hand, Maryland Governor Martin O’Malley decided to allow fracking go forward in the western part of the state. This decision was based on a joint report from  the Maryland Departments of the Environment and Natural Resources, which concluded that with adequate regulation, “the risks of Marcellus Shale development can be managed to an acceptable level.” Both reports acknowledged that there are risks from fracking, due primarily to groundwater and air contamination, but also that there is a great deal that is not known about the extent of these risks, or the long term effects.

The articles concludes “that these two decisions on fracking, while draped in scientific language, were — in fact — probably not really scientific decisions at all.” Thank you Washington Post for pointing out what grassroots activists have known for years – that most decisions about environmental risks are based on political, economic and other factors, and not on available science, no matter what anyone tells you.

The article goes on to attribute the different decisions to four factors – politics, who did the studies for each state, the amount of land affected and the use of the precautionary principle by one state (NY) and not the other. All these factors liked came into play, but there‘s another factor not mentioned that likely played an even larger role, and that is the role of grassroots activism. In New York, grassroots activists were overwhelmingly opposed to fracking and this position was repeatedly made known to Cuomo and other state decision-makers. Since being elected in 2010 Cuomo could not go anywhere in the state without seeing signs asking him to ban fracking. This message was delivered time after time by numerous groups in New York as well as by celebrities, scientists and others.

The lesson here isn’t that reasonable agencies and state governors came to different decisions based on different evidence and information. It’s that the grassroots activism in New York made a huge difference and helped convince Cuomo and other decision makers in the state that there was enough known about the risks posed by fracking not to move forward and that the unknown risks were too serious to ignore.