The big debate over what is a "safe" level
Pete Myers for the Environmental Health News
I'm
the founder and chief scientist of Environmental Health Sciences, a nonprofit
launched in Charlottesville, Virginia, that publishes Environmental Health News
and engages in scientific research and outreach to help the public and policy
makers understand that we have many opportunities to prevent diseases and
disabilities that are afflicting our families, friends and neighbors today.
We
can accomplish this by acting upon today's scientific understanding that
chemical exposures are contributing to those problems.
I'm
going to let you in on a scientific reality that is going to transform the
chemical enterprise and upend today's unscientific approach to figuring out
what's safe and what is not.
The safe dose of one of the biggest volume chemicals in the world— bisphenol A (BPA)—will have to be reduced by at least 20,000-fold.
The safe dose of one of the biggest volume chemicals in the world— bisphenol A (BPA)—will have to be reduced by at least 20,000-fold.
This
calculation is based upon data the US Food and Drug Administration (FDA)
obtained in an ambitious, roughly $30 million collaborative program called
CLARITY-BPA.
CLARITY was designed to reconcile differences between traditional regulatory science as practiced by the FDA and results obtained by independent academic scientists funded by the National Institute of Environmental Health Sciences (NIEHS). Many significant effects were observed at the lowest dose tested, including data obtained by the FDA.
CLARITY was designed to reconcile differences between traditional regulatory science as practiced by the FDA and results obtained by independent academic scientists funded by the National Institute of Environmental Health Sciences (NIEHS). Many significant effects were observed at the lowest dose tested, including data obtained by the FDA.
That
means: Take today's FDA reference dose and divide by at least 20,000.
That's
the highest exposure that would be considered safe if regulated according to
existing scientific understanding. The chemical would disappear from any uses
that bring it into contact with food or drinking water, human skin, or result
in it evaporating into the air or melting into water.
And the same would hold for many other chemicals that disrupt hormone signaling, that is, endocrine disrupting chemicals, which have been linked to multiple health impacts including prostate cancer, breast cancer, infertility, diabetes, ADHD and autism.
Maybe
not all EDCs would require a 20,000-fold reduction. Perhaps only a 1000-fold.
But there are at least several hundred endocrine disrupting chemicals (EDCs) in
use today that could follow this pattern. All would see greatly heightened
restrictions on their uses.
And
that represents an existential threat to the chemical industry.
Risky
investments
I
am not anti-chemical, nor anti-chemist. We need chemicals, including plastics,
to make modern civilization work. What we need, however, is to do a much better
job at designing the next generation of inherently safer materials, safer than
the mix we have today, which has been deployed with far too little attention to
its inherent toxicity.
I've
spent a significant part of my work over the last decade helping
chemists design safer chemicals. I want to help them grab market
share in the booming demand for safer materials. I want to help them make
money.
Some
people claim that chemical regulations stifle innovation. Just the opposite is
true. It will require tremendous innovation to move away from hazardous
chemicals and toward materials that are safer.
It can be done. The scientific knowledge we possess today about what causes chemical harm is deep and wide, so much better than what we knew when hazardous materials in widespread use today were designed.. Let's use that knowledge to innovate.
It can be done. The scientific knowledge we possess today about what causes chemical harm is deep and wide, so much better than what we knew when hazardous materials in widespread use today were designed.. Let's use that knowledge to innovate.
What's
the long-term landscape? A series of events and scientific discoveries over the
last two decades are revealing that not only have long-standing chemical
industry practices harmed people's health, investors taking positions in
chemical companies may be exposing their wealth to unexpected and large
financial risks.
These
risks arise from a core reality of the business of establishing what is safe
and what is not:
Chemicals are not thoroughly tested—if at all—for safety before being released into the market, resulting in widespread if not universal exposure, including to highly vulnerable populations like babies still in the womb. Serious harmful effects often are not detected until decades later.
Chemicals are not thoroughly tested—if at all—for safety before being released into the market, resulting in widespread if not universal exposure, including to highly vulnerable populations like babies still in the womb. Serious harmful effects often are not detected until decades later.
All too often, as effects are discovered the responsible party—which made the initial mistake to incorporate a poorly understood chemical in products and take them to global scale—doubles down in efforts to hide or dismiss concerns about safety, using toolkits to manufacture doubt developed by the tobacco and lead industries.
Internal
memos obtained through legal discovery reveal that the companies, sometimes
decades earlier, had ignored or hidden scientific evidence that raised safety
concerns. Three prominent examples emerged in in the past few years alone:
Monsanto/Bayer with the Roundup herbicide, Johnson & Johnson with asbestos
in its talc baby powder, and 3M and DuPont with their manufacture and use of
perfluorinated Teflon-related "forever" chemicals, PFAS.
Thousands
of lawsuits are being heard against those companies now. Shareholder values
plummet as juries reach decisions. Billions of dollars are at stake. And there
will be more.
Monsanto
had earned a bad rap for misbehavior with its chemicals for decades. But
Johnson and Johnson, 3M and DuPont didn't. They had been widely regarded as
good corporate citizens. If even they have laundry this dirty
in their past, how many other companies have pursued similar practices?
Unquestionably many.
Weaponized
data
But
with the practices so widespread, perhaps the pertinent question is, can any
company within this sector be presumed innocent? It's just too common a
business practice. It's standard operating procedure.
Another
example: Bill Moyers' 2001 documentary Trade Secrets unveiled an early 1970s conspiracy by
several seemingly respected chemical companies to hide devastating scientific discoveries
about the health risks of vinyl chloride, one of the most important chemicals
for the plastics industry. The conspiracy involved Conoco, BF Goodrich, Dow,
Shell, Ethyl and Union Carbide, some of the founding fathers of the chemical
revolution.
A
new weapon against these bad practices has emerged and matured since the
tobacco settlements of the late 1980s: the creation of large, searchable
databases of internal documents obtained through legal discovery in lawsuits,
showing what the companies knew and when they knew it, and also how they
conspired with federal agencies to derail needed safety regulations.
The
two biggest databases are the Chemical Industry Documents Library at the University
of California San Francisco, and ToxicDocs,
a similar database of 20 million internal documents dating back as far as 1920,
hosted by Columbia University and City University of New York. The UCSF library
now includes a large set of documents released by the Attorney General of
Minnesota upon settlement of an $850 million suit against 3M last February.
The
lawsuits currently underway against Monsanto/Bayer, 3M and Johnson &
Johnson will undoubtedly add additional documents that provide yet more
evidence of cover-ups that commenced long ago. It already is a positive
feedback loop, as new documents add to the body of evidence, which then
stimulate more lawsuits.
Science
of harm
Financial
risks arise for chemical industry investments from a different direction as
well: the advance of science demonstrating harm, and the evolution of science
to determine what is safe.
The
discovery of harm can be slow arriving—sometimes decades after a chemical is
first put on the market—but impacts of harm can nonetheless be devastating.
For
example, 3M's and DuPont's forever chemicals (perfluorinated
compounds, or PFAS, which degrade very slowly in the environment, if at all)
were first used in products in the 1940s.
Scientific concerns about them started to appear in the 1990s, although internal documents indicate the companies had known decades earlier. Most of the concerns have been about cancer, low birth weights, immune system function and birth defects.
Scientific concerns about them started to appear in the 1990s, although internal documents indicate the companies had known decades earlier. Most of the concerns have been about cancer, low birth weights, immune system function and birth defects.
Last
year, a science team in Italy unveiled results revealing
a new, different set of adverse impacts, this time on male reproduction. They
include decreased penis size, reduced sperm count and structural changes in the
reproductive tract, classic signs of endocrine disruption. And the team's
research confirmed that the contaminants interfere with testosterone action.
Even
without the penis effect, 3M settled that $850M suit with the State of
Minnesota. DuPont settled a case in West Virginia for $671 million in 2017 and
this month the film Dark Waters starring Mark Ruffalo tells
the story of the company's decades-long treachery. New Hampshire, New Jersey
and New York have ongoing lawsuits.
As
of the end of 2019, research by the U.S. military, the Environmental Working
Group and others have documented PFAS contamination in more than 400 sites
around the U.S. According to one analysis, 110 million Americans have drinking
water contaminated by unsafe levels of these chemicals.
This estimate is likely to grow substantially with the discovery of PFAS in artificial turf and leaching therefrom into surface water, and the haphazard disposal of untold tons of artificial turf once it wears out and must be replaced.
This estimate is likely to grow substantially with the discovery of PFAS in artificial turf and leaching therefrom into surface water, and the haphazard disposal of untold tons of artificial turf once it wears out and must be replaced.
Many
other suits will unquestionably be filed. And that's just in the U.S. These chemicals
have already created furors about public health in Australia and Canada.
Upending
dangerous assumptions
But
if there is an existential threat on the horizon for the chemical enterprise,
it's the compelling evidence that two of the most basic assumptions used by
regulatory agencies to determine what is safe and what is not are flat out
wrong. One assumption is that it's sufficient to examine chemicals one at a
time.
The second bedrock assumption is that high dose testing can be used to detect low dose effects. These assumptions have underpinned literally every single risk assessment (what's safe and what's not) of a chemical that has ever been done anywhere in the world.
The second bedrock assumption is that high dose testing can be used to detect low dose effects. These assumptions have underpinned literally every single risk assessment (what's safe and what's not) of a chemical that has ever been done anywhere in the world.
"One
at a time" fails because it doesn't acknowledge that no one is ever
exposed to just one chemical at a time. We are exposed to hundreds if not
thousands.
What
does every physician ask a patient for whom the doc is about to prescribe a
drug? What medicines are you already taking?
That's because chemicals interact.
One of the most ridiculous uses of this assumption is perhaps in testing pesticides. The EPA tests the "active" ingredient of a pesticide. Yet the pesticide that is available for purchase is a mixture of dozens of chemicals, many of which are added to the product sold explicitly to ENHANCE THE IMPACT OF THE ACTIVE INGREDIENT.
That's because chemicals interact.
One of the most ridiculous uses of this assumption is perhaps in testing pesticides. The EPA tests the "active" ingredient of a pesticide. Yet the pesticide that is available for purchase is a mixture of dozens of chemicals, many of which are added to the product sold explicitly to ENHANCE THE IMPACT OF THE ACTIVE INGREDIENT.
How
can you assess pesticide safety without considering the whole product, not just
the active ingredient? You can't.
"High
dose testing" falls on the sword of what endocrinologists call "non-monotonicity."
Many syllables, but a simple concept: Hormones, and chemicals that behave like
or interfere with hormones, do different things at different doses. There are
many examples of this in the scientific literature of endocrinology, the study
of hormones.
This is an anathema to traditional and regulatory toxicology, because that "science" maintains that "the dose makes the poison," which the regulatory agencies interpret to mean "higher doses have bigger effects."
This is an anathema to traditional and regulatory toxicology, because that "science" maintains that "the dose makes the poison," which the regulatory agencies interpret to mean "higher doses have bigger effects."
EHN recruited a reporter, Lynne Peeples, to investigate the FDA's execution of the roughly $30 million project to reconcile their conclusions with the work of 14 independent academic labs showing harm at low levels for over a year. The investigation found that the FDA worked to ignore or discredit independent evidence of harm while favoring pro-industry science despite significant shortcomings.
Key to their conclusions was rejecting statistically significant non-monotonic patterns in their own data, because, they asserted, the non-monotonic findings were not biologically meaningful. In other words, non-monotonic patterns aren't real.
"The
dose makes the poison" seems like common sense, but common sense has
failed us many times in the past.
Think about quantum physics or plate tectonics. Our understanding of the modern world depends upon the practical implications of those discoveries.
Non-monotonicity isn't nearly as revolutionary as those scientific fields, but it is profoundly important for human health. And it is a standard, widely accepted concept in endocrinology and pharmacology. In 2012, the then-Director of NIEHS, Linda Birnbaum, editorialized that non-monotonicity should be the default assumption in the study of EDCs.
Think about quantum physics or plate tectonics. Our understanding of the modern world depends upon the practical implications of those discoveries.
Non-monotonicity isn't nearly as revolutionary as those scientific fields, but it is profoundly important for human health. And it is a standard, widely accepted concept in endocrinology and pharmacology. In 2012, the then-Director of NIEHS, Linda Birnbaum, editorialized that non-monotonicity should be the default assumption in the study of EDCs.
While
there are multiple molecular mechanisms leading to non-monotonicity, the
easiest (but incomplete) way to think about it is this: Hormones and endocrine
disrupting compounds turn on one set of genes at one dose, and another at
higher.
Sometimes the higher dose turns on genes that shut down the genes that were stimulated by the low dose. In this case, the effect of the low dose is not visible when using high doses. It's analogous to the way a thermostat works. If the room is cold, the furnace is on. But when the temperature hits the desired temperature, the thermostat turns the furnace off.
Sometimes the higher dose turns on genes that shut down the genes that were stimulated by the low dose. In this case, the effect of the low dose is not visible when using high doses. It's analogous to the way a thermostat works. If the room is cold, the furnace is on. But when the temperature hits the desired temperature, the thermostat turns the furnace off.
Sometimes
the high dose is so high that instead of turning on genes it becomes overtly
toxic. Here's an example: doses of one part per billion of a specific endocrine
disrupting chemical delivered to an infant rat causes morbid obesity as the
animal matures. This is research by the U.S. National Institute of
Environmental Health Sciences. In contrast, a dose of the same compound 1,000
times higher causes weight loss.
The
vital piece of information needed to understand why this invalidates today's
chemical safety testing requires understanding how the regulatory tests are
performed. The lab doing the safety testing starts at high doses and then
delivers lower and lower doses to different test groups.
Once they find a dose that no longer causes a difference between the exposed and the control animals, testing stops. They use a series of safety factors, usually dividing that no effect dose by 1,000, to estimate the safe dose.
Once they find a dose that no longer causes a difference between the exposed and the control animals, testing stops. They use a series of safety factors, usually dividing that no effect dose by 1,000, to estimate the safe dose.
Seems
logical. Seems common sense. If dose X doesn't cause an effect, dose X divided
by 1,000 is surely safe. But endocrinology doesn't work that way. That might
defy common sense, but it is scientific reality.
And unfortunately, because it seems so logical, the regulatory agencies in standard mode NEVER test at the estimated safe dose. 1,000-fold below? Why bother.
And unfortunately, because it seems so logical, the regulatory agencies in standard mode NEVER test at the estimated safe dose. 1,000-fold below? Why bother.
To
save money and time, they assume that the dose 1,000-fold lower is safe.
Unfortunately, many
published scientific papers now show that doses way below the
"no effect" dose can cause serious adverse effects. It isn't that the
high doses are safer. They, too, cause problems. It's that the effects are
different. The low dose effects are serious too—like morbid obesity and reduced
fertility.
Here's
the one very practical implication I mentioned at the beginning: If the FDA
were to acknowledge statistically significant non-monotonicity in their test of
BPA—which analysis by independent scientists has confirmed—the safe dose of
would be reduced by a factor of more than 20,000-fold. BPA would become
virtually unusable.
For
a webinar from Carnegie Mellon University featuring four of the world's leading
experts on BPA explaining this calculation, go here.
This webinar contains four presentations all focused on the FDA-NIEHS
collaboration called CLARITY-BPA.
The presentations work through why CLARITY was launched, what was found by the FDA 'guideline' study (conducted like a standard regulatory test but including low doses), what was found by 14 independent academic laboratories who also were part of CLARITY, and analysis of what it means.
The presentations work through why CLARITY was launched, what was found by the FDA 'guideline' study (conducted like a standard regulatory test but including low doses), what was found by 14 independent academic laboratories who also were part of CLARITY, and analysis of what it means.
Bisphenol
A is one of the plastics industry's most important molecules. Incredibly cheap
to make, incredibly abundant in production, incredibly important to the bottom
line. Also—incredibly dangerous to human health.
Removing
that one molecule alone would send tectonic signals throughout the chemical
enterprise. And yet BPA is but one of at least a hundred or more molecules that
have non-monotonic patterns.
The replacement chemicals for BPA currently touted as 'BPA-free' are likely to be among them, although many have not been tested. 'BPA-free' does not mean 'safe.'
The replacement chemicals for BPA currently touted as 'BPA-free' are likely to be among them, although many have not been tested. 'BPA-free' does not mean 'safe.'
Non-monotonicity
is truly an existential threat to today's chemical enterprise. If that
enterprise is to become sustainable, it must embrace this basic
endocrinological reality.
Embracing
it is a path to reversing today's epidemics of chronic diseases that are
driven, at least in part, by chemical hacking of the hormone messaging system
by endocrine disrupting compounds.
Pete
Myers, is board chair and chief scientist of Environmental Health Sciences. He
is also the founder of EHN, though the publication is editorially independent.