Posts Tagged ‘Toxicology’
A Woman of Substance: Theo Colborn 1927-2014
Sad news came on Sunday that Dr. Theo Colborn had died at the age of 87.
F. Scott Fitzgerald said there are no second acts in American lives, but he said that well before the woman's movement of the 1970's flourished and allowed an entire generation to experience one. Dr. Colborn's second act just happened to change the entire debate over environmental health.
Theo Colborn had already retired from her first occupation as a pharmacist, when at age 58, she decided to go back to school in 1985. She got a PhD in Zoology from the University of Wisconsin, with minors in epidemiology, toxicology and water chemistry. She told a PBS film crew that she wanted to get an education so that "maybe I could undo some of the things my generation basically foisted on society."
After school she began working on clean air issues in Washington DC but then went back to the Midwest to join a comprehensive study on the pollution affecting the Great Lakes. This gave her a chance to review emerging science from a more holistic viewpoint than a specific "reductionist" academic discipline or specialty. She was looking at an entire ecosystem. Although there was lots of new literature on the subject of how chemicals were impacting different species in the Great Lakes region, no one was pooling the research for evidence of possible trends, similarities and effects. She began to use the new tool of computer spreadsheets to do just that…for the very first time.
Her results surprised her and launched a new career that lasted right up until Sunday. What was doing the most harm to Great Lakes animals were not one-off catastrophic events like accidental pipe ruptures that dumped thousands of gallons of industrial poisons into the water, but the long-term, low-level assault by a variety of everyday synthetic chemicals. Their worlds were ending not with a bang, but a whimper.
Cancer was the big sexy health effect from pollution that everyone was looking for back then, but it was notoriously hard to prove a link between a polluting cause and a cancerous effect. Colborn's research discovered many more subtle, more insidious, impacts from pollution at levels which were officially "below regulatory concern" – first in the biology of animals, then in people.
Fetuses were particularly vulnerable to these impacts, which affected how hormones could change the shape and function of internal organs, reduce the ability of an animal to behave "normally" in its environment, harm the immune system's ability to respond to routine threats, even warp reproductive systems in gender-twisting ways that seemed to remake males into females and females into males. Such changes weren't necessarily fatal like cancer, but were being passed on from generation to generation until a species could no longer reproduce healthy versions of itself. The biological Xerox machine kept malfunctioning in small and large ways over time until the copies no longer looked like the originals. Because animals had shorter life cycles, you could see the effects of these changes add up much quicker than you could in humans, but Colborn had no doubt that similar effects were occurring within our own species as well.
This field of research was so new, it didn't even have a name. In 1991, she and 20 other scientists investigating it gave it one – endocrine disruption. In 1995 she and three others wrote the founding document of this new science, the best-selling book, "Our Stolen Future" chronicling how everyday, ubiquitous man-made chemicals were impacting human development. Not since Rachel Carson's "Silent Spring" (another work by another woman who was thinking outside the box) had a single book so challenged the conventional ideas about pollution and its impact. It remains required reading for any environmental activist.
If you were doing field work around industrial pollution sites in the 1990's, as Downwinders at Risk was in Midlothian with its three cement plants, one of which was the largest burner of hazardous waste in the state of Texas, the book instantly connected the dots between what was coming out of the smokestacks and the strange health effects being reported by local citizens. It was the constant exposure to the toxic soup of dozens of contaminants that could be the explanation behind inexplicable birth defects of almost any animal population being breed near-by, as well as the heretofore unknown health effects among the plants' neighbors. Reading the book, one felt like you'd discovered the Rosetta Stone of environmental health.
Every article you've ever read about the possible dangers of the plastic packaging additive BPA, or declining sperm counts in males all over the world, or male fish behaving like female fish, can be traced back to Theo Coburn and her peers who founded the field of endocrine disruption. Subsequent science has linked pollution exposure to Parkinson's disease, autism and obesity. Her overarching point was that we are swimming in a sea of industrial chemicals without knowing very much at all about their effect to the human body. That thesis is being proved right almost weekly by scientists, some of whom were not even born when Colborn decided to embark on her second career.
Her lifetime spanned the maturity of the environmental movement itself, from conservation-minded tree hugging concerns to people-poisoning invasions of the body snatchers health effects. There's no imagining the contributions she could have made had she devoted the first part of her adult life to the cause, but the entire human race is a beneficiary of her decision not to stay a retired pharmacist. She did not go quietly into that good night. She turned the world upside down on her way out. R.I.P.
Another Study Reveals Why Our System of “Safe Levels” is a Tragic Mirage
Gas well, cement plant, lead smelter, plastics plant, refinery, compressor, incinerator. Anyone who's ever lived next door to an industrial polluter knows there's the way the facility appears to be operating on paper and how it's actually operating in the real world.
The way it's operating on paper is completely portable. You can take this version of the facility anywhere. The numbers and printouts and charts can show up to congressional hearings. They can be included in PowerPoint presentations, along with glossy pics of the place itself. They can be summarized. They have no smell. They have no texture. They don't make a sound. On paper, expressed in language and figures, the facility may seem to be operating properly under every permitted limit it has to abide by.
On the ground however, it may be a completely different story. It may mean strange petrochemical or plastic smells wafting through your house in the middle of the night. It could mean a series of loud explosions or pops that nobody has ever been able to explain to you. It could mean rashes on your skin, or headaches, or nausea, or asthma attacks. It could mean living in fear of chemical assault. All the time.
This version of operations is not portable. One can write about it or talk about it, but that will not put other people there. And indeed, descriptions of these circumstances can sound so nightmarish that listeners assume you're exaggerating. You're not. Not even video or film can immerse you in it. No amount of reporting about it can make you feel in it. The map is not the place. The only way to know this side of operations is to live it. Day in, day out.
The difference between what the paper version of polluting says, and what the people living it know, is a front line of social justice in the 21st Century.
It also happens to be a major frontline for science, as demonstrated by a recent landmark study from, of all places, Texas Tech about how the sum of pollution is greater than its sometimes desperate parts We're late in covering this, but thanks to the Denton Record Chronicle's for bringing it to our attention back in June. Because this study underscores once again in a big way why our entire system of regulating chemical exposures is so completely contrary to what we know about how those exposures are affecting us.
Tech scientists took two chemicals that are known to cause cancer in large amounts, arsenic and estrogen, and exposed human prostate cells to very low amounts of each. The amounts they exposed the prostate cells to were so low, they fell below the EPA regulatory "safe" level that limits releases of the chemicals from polluters. Individually, the exposures of the cells to arsenic and estrogen were so low as to believed to be harmless. But they weren't.
Instead, the Tech researcher's peer-reviewed, journal-published study found the combination of the low doses of the two chemicals combined was almost twice as likely to create cancer in the prostate cells as the single chemical exposures individually. That is, the toxic interaction or "cumulative effect" of the two chemicals was more than the sum of their parts. There was a "synergestic" reaction inside the cells that the current regulatory system doesn't recognize as even a possibility.
“The majority of cancers are caused by environmental influences,” Singh said. “Only about 5 to 10 percent of cancers are due to genetic predisposition. Science has looked at these chemicals, such as arsenic, and tested them in a lab to find the amounts that may cause cancer. But that’s just a single chemical in a single test. In the real world, we are getting exposed to many chemicals at once.”
Singh became interested in looking at arsenic because water well problems in his native India had recently highlighted mass poisonings from contamination of the chemical. He wondered how this exposure would interact with other carcinogens within the same population.
He focused on estrogen as the second chemical because of the chemical’s ubiquity. Many plastics, such as food can liners, release bisphenol A (BPA), and other chemicals that mimic estrogen in the body.
Unlike more potent chemicals that do major damage to the DNA in a cell, such as benzene, arsenic and estrogen aren’t major mutagens Singh said. Instead, their presence tends to stop certain genes from expressing. The process is called DNA hypermethylation.
…the two chemicals stopped the MLH1 gene, which is responsible for sending the signal to start the self-destruct sequence when a cell is damaged. Because the self-destruct couldn’t activate, the cells became cancerous after exposure.
“With the lower dose not killing the cell, it’s causing damages that go under the cell’s radar. We found when you have two compounds together, lower doses could be more serious problem.”
This is what's called a non-linear impact. You can actually get harmed more by long term low-level exposures than by intense bursts of short term exposure – exactly the opposite of the way the system regulates chemical exposures now.
Currently that system assumes it can protect the public health from exposures to over 80,000 chemicals on the marketplace by regulating the average intake of these chemicals one at a time. It says: "we know that lead and benzene are bad for you if you OD on them, but by only exposing you to a little bit every day, we can keep you from getting damaged by its health effects." The dose is the poison. A little bit cant hurt you, but a lot can kill you.
Unfortunately, this view, which is the foundation for all modern regulatory schemes for chemical pollution, is based on a worldview of human physiology that's now dangerously out of date. For the past 50 years at least, study after study has shown that there are a lot of less-than-drop-dead health effects that couldn't be diagnosed without modern technology. The more we learn about how how bodies work the more we learn new ways about how chemicals can really screw them up. The Tech study is just the latest, albeit dramatic example.
Moreover, of those 80,00 chemicals only about 200 can be said to have been studied even remotely "thoroughly" and fewer that that have been examined for their interactions with any of the other 79,999. So the system itself is a big fat theory in progress, with very little real science supporting it. We're all its Guinea Pigs. It's an hypothesis.
But its a hypothesis with billions invested in it. So to prove it wrong is to threaten a lot of people with a lot of money.
Which is why the chemical industrial-government complex is trying very hard to hold back the tide of this kind of science and what it means. Meanwhile the gap between the paper version of how things are operating at a facility and the real world impact of those operations continue to grow. At some point the contradictions will be too much to ignore or withstand. But we're a long way from that point yet. Which is why we need your help to keep fighting on behalf of those folks living the truth on the ground and prevent more victims of this obsolete and harmful regulatory system.
The Dose No Longer Makes the Poison, But We Regulate It As if It Does
It may come as a shock, but the EPA and industry view exposures to toxic chemicals in basically the same way that a famous 16th-Century occultist named Paracelsus did over 500 years ago: The amount of exposure to a chemical determines its toxicity; the higher the dose, the more toxic it is. The lower the dose, the more benign. "The dose makes the poison."
This approach says there's a linear one-to-one relationship between volume and harm. It's the basis of all federal, state and local environmental health regulation. It's what drives government "risk assessments." It's what allows there to be such things as "safe levels" of things that don't sound very safe.
But, what if this approach didn't capture all of what was going on physiologically between poison and victim? What if there were different effects happening at the cellular level? What if, like the Renaissance-born theory of Newtonian physics, it couldn't account for phenomenon on a smaller-scale because it didn't have the ability to see it? What if there were certain poisons that,
"depict a weird world of endocrine disruption that is as different from traditional toxicology as quantum mechanics is from the staid clockwork of Newtonian physics. When even minuscule quantities of BPA and other disrupters interact with hormone receptors at crucial moments in development — activating, jamming, hijacking or otherwise messing with their normal function — they can give rise to strange-looking experimental results, especially when other hormones are thrown into the mix."
From the journal Nature comes a case study in why no self-respecting thinking person would trust the current regulatory system to give them the final word on whether any given chemical exposure is "safe" or not.
A citizen can't underestimate the kind of threat this research presents to the Environmental Industrial and Legal Complex. Every permit ever written and awarded. Every environmental law every passed. They all depend on a Paracelsusian view of the world. Prove a different world exists and it turns everything upside down.
"A growing number of academic researchers are making just such a claim for endocrine disrupters, a large group of synthetic chemicals able to interact with cellular hormone receptors. These compounds, which range from the common weed killer atrazine and the plasticizer bisphenol A (BPA) to the antibacterial agent triclosan (used in cleansers) and the vineyard fungicide vinclozolin, don't play by the usual rules of toxicology. On the basis of conventional high-dose testing, regulators have set maximum acceptable levels for each of them that assume all doses below that level are safe. But academic researchers who have studied a wider range of doses, including very low ones found in the everyday environment, say that their experiments usually do not generate the tidy, familiar 'ski-slope' dose-response graphs of classic toxicology. Instead, most endocrine disrupters have 'non-monotonic' dose-response curves, meaning that their slopes change at least once from negative to positive, or vice versa, forming 'U' shapes, inverted 'U's or even stranger shapes that resemble undulating Chinese dragons."
It's not just endocrine disruptors that are challenging tradition. We're already seeing the contradiction between the latest science and regulations when it comes to old-fashioned poisons like lead and soot. There's a scientific consensus among the frontline researchers that there's no safe level of exposure to either one of these toxic substances, And yet, permits are still being written to allow what regulators claim are "safe levels" of them to be spewed into the air and our lungs.
Locally, UT Southwestern epidemiologist Dr. Robert Haley's groundbreaking work on Gulf War Syndrome has found similar effects in studying exposure of veterans to very low doses of nerve agents. Levels of substances that weren't supposed to make people sick individually seem to have a harmful synergistic effect when combined.
The more we can see what's happening at the smallest levels of things – whether its the vibrations of atoms in the chair you're sitting in, or the nuance of chemicals in the cells of a developing fetus – the more we find out that things are more complicated than they appear. Science is pushing us in the direction of a "Precautionary Principle" approach to regulating human chemical exposure. That's a radically different perspective that undermines the billions invested in the status quo allowing continual low level poisoning. After 500 years, maybe it's time to find a new model.