By Carolyn Raffensperger
1. There are taxonomies of human health and disease. Taxonomies are conceptual frameworks that organize our thinking by grouping things that share characteristics. One taxonomy of disease is based on the system of the body that is diseased: the endocrine system, the cardiovascular system, the nervous system. Within those systems there can be various disorders such as birth defects, cancer, or poisoning. Another taxonomy is the kind of disease: infectious disease, injuries, or chronic disease, as examples. Within the category of those diseases there can be further subdivisions. Within the domain of infectious diseases there are those known as zoonotic diseases. These are diseases that cross between species and are often carried by a vector such as mosquitoes or ticks.
2. Epidemiology specializes in two kinds of disease, infectious and chronic. Frequently epidemiologists studying infectious disease investigate causes because there is usually a direct cause and a single effect with infectious diseases. Chronic disease specialists often study effects because many chronic diseases have multi-factorial causes making it harder to study causes.
3. Since the rise of industrialization the disease pattern has changed from primarily infectious disease to primarily chronic disease. Small pox and polio have been replaced by cardiovascular disease, diabetes and asthma.
4. When it focuses on effects, rather than causes of chronic disease, the medical professions emphasize treatment of disease, rather than prevention of disease.
5. The causes of chronic diseases are often complex, ecological (both biological and geological) and result from cumulative impacts of multiple stressors.
6. Within the category of chronic disease there is a subset of diseases that are Geonotic. That is, they are geologic, mineral or chemical in nature. These diseases result from disruptions or alterations in the geosphere. The vector or cause of the diseases are not living organisms, but geochemical materials.
7. Some Geonotic diseases can be passed from the Earth to humans and from humans to the Earth. This is a feedback loop between the geochemical cycles of the Earth and living systems.
8. Kinds of Geonotic disease causes
- A. concentrating geologic materials such as carbon or nitrogen–aerosol loading and air pollution, nitrogen loading and water pollution
- B. creating and using toxic chemicals such as DDT
- C. altering geochemical cycles such as nitrogen, calcium, phosphorus in the body and on the Earth
- D. depleting certain materials such as phosphorus
- E. dispersing some materials such as mercury
9. Examples of kinds of Geonotic diseases
- A. Lead, Mercury and Arsenic poisoning
- B. Asthma
- C. Many cancer
- D.Blue baby syndrome.
- E. Asbestosis
- F. Black Lung Disease
- G. Phosphorus deficiency
10. Almost all of the Geonotic diseases can be attributed to violating ecological systems conditions as expressed in frameworks like the Natural Step.
11. Every geospherical system has been affected by human disruption: air, water, soil, fire, the deep Earth.
12. Scale matters with Geonotic diseases. Large scale mining such as mountain top removal or fracking, or oil drilling in the gulf, industrialized agriculture that concentrates and disrupts materials like nitrogen and selenium all have serious geologic consequences that are direct causes of human health disease. The garbage patch and the massive quantities of plastic (a geologic material) in the ocean, in addition to the acidification of the ocean changes the ecology of the ocean in ways that affect human health. Similarly small, micro changes in the human body of iron, calcium, phosphorus or endocrine disrupting chemicals can lead to serious diseases from reproductive and neurological disorders to obesity.
13. Increasingly infectious disease will be a result of geologic disturbances such as greater heat, more flooding which will alter the habitat of humans and biological vectors.
14. Ultimately, humans have replaced their relationship with the sun and with plants, to a relationship with fossil fuels and the internal combustion engine. These new relationships are not conducive to health.
Geonotic diseases are a taxonomic reality of ecological medicine which is based on the truism that humans are as healthy (or not) as the surrounding environment. Unless we change course, the future of human disease is more geonotic chronic diseases. The future of the Earth is more disruptions of natural systems that will create more human disease and more disease of other living things.
By Nancy Myers
“This is not sustainable,” I kept thinking during the two weeks I spent recently in the largest city in the poorest country in the world. Nothing about life in Kinshasa, DR Congo, fit any reasonable definition of sustainable.
The food I ate came either from another country or from the surrounding countryside, hauled in by overloaded, crumbling, fuel-consuming vehicles over crumbling roads. Every sip of water I swallowed was from a plastic bottle. Every excursion—to visit new friends, attend a church service, check in on a job-training workshop, attend a funeral, go out to dinner—required getting in a vehicle and crossing varying lengths and breadths of this sprawling city over roads that ranged from dangerous to impossible and, more likely than not, encountering horrendous traffic jams. People, people, everywhere, were busily walking, riding, finding a hustle through the day—only 3 percent have regular employment. The population is exploding. Six or seven children per family is still the norm.
The heat at the coolest time of year was tolerable (for me, a Northerner) only if the electricity was on, powering a fan or air conditioner. My requirement for natural beauty was met only on a sunset walk by the Congo River and a day trip outside the city into the gorgeous countryside. Little remained of the tree-lined grace I remembered in parts of this city that I had known in the 1970s. No wonder my eyes turned hungrily to the stunning fashion parade—Congolese women create their own beauty—which you can see on any ride through this dirty, trash-strewn, polluted city.
I could not live in Kinshasa for long. And yet I still love this impossible country, perhaps even more than I did when my husband and I lived and worked here (in other cities) for three years when we were very young. And, after this belated return visit, I find myself wanting to go back. Why?
As an environmentalist, I see the bad news and the worse news to come. I see, even, a snapshot of our own future—if not ours personally, for future generations of widening swaths of the world. But I also see something else. I see that people are, nevertheless, living in Kinshasa and will live there for some time to come. And many manage to do so with an enviable vigor and grace.
I see that in focusing on the unsustainability, the wars, the suffering, and all the bad news so readily visible in Congo—as we environmentalists and the international media can’t help doing—we miss something. I am trying to define what it is that we miss, without romanticizing what I observed about the human spirit that still operates among the poorest of the world’s poor. I must qualify that. My conversations were not really with the poorest. They were mostly with people whom I would consider peers—well-educated professionals (with or without employment) and fellow members of my faith community.
What struck me was that they were all doing their absolute best. They were operating at the edge of their capabilities and the opportunities available to them. They were doing what they could, both to provide for their own families and to take care of others and the greater society. They were scraping together all available resources—monetary, spiritual, human connections—to survive, to do well, and to do good. And they did so with the extraordinary grace that comes with their culture’s appreciation of joy, affection, and hospitality. Can we say the same about ourselves, with all our advantages?
Life in Kinshasa is not sustainable, but it will continue for a long time. And it may hold lessons for all of us about how to live in difficult times.
This is Earth Day weekend. Yesterday I gathered nettles and garlic mustard to eat. I will do my laundry tomorrow because it is raining today, and I want to hang clothes out to dry. These are Earth Day kinds of things to do. But every day is Earth Day in the woods where I live. How can it not be? I sometimes look up at the tall trees and feel like I am nestled in the Earth’s hair.
Think about that analogy, however, and you start feeling like a louse. Or a tick. Yes, a tick. This house, sitting here in its little cleared space, perhaps feels to Gaia like a fat tick that won’t let go. How annoying is that!
In any case, it’s a reminder to be as kind and respectful to our hostess as we can, given that we are parasites and utterly dependent on her.
I often feel like a fraudulent environmentalist, however, even though it is my profession. Last Sunday we encountered one of our younger friends who is a real environmentalist. He has hiked the Appalachian Trail. He has developed organic gardens. He has gotten a graduate degree in sustainable agriculture. He is looking for a place to till his own soil and live well but lightly on the land. He is fascinated by farming with horses. He is dedicated, persistent, and propelled by idealism and conviction. Gaia needs more 30-somethings like Jon.
Oddly, Jon seems to admire my husband and me, consider us mentors. I think it’s because I told him that I once spent a weekend with Wendell Berry, the poet-essayist elder of all things sustainable. On Berry’s Kentucky farm. Talking around his kitchen table. With half a dozen other people who were real environmentalists.
I’m not sure what I think a real environmentalist is or should be, just that it’s not my husband and me. We’re not exactly living off the grid out here in the woods. We have to drive everywhere. Vic still drives to Chicago to work in the middle of every week. Working for an environmental organization is not a be-all and end-all calling for me. I have many interests and could work in another profession.
Who we are is ordinary middle-class people who have come gradually to consciousness about, and love for, Mother Earth. Vic would not call himself an environmentalist but he reads incessantly about climate change—and has since the 1980s. I hesitate to call myself an environmentalist but I have worked for an environmental organization for 12 years because I love the people in this little band (real environmentalists) and what they are doing, and because they really put my writing and editing skills to good use. I admire them, like Jon admires me. I have learned from them and I keep learning. If I am an environmentalist now, I give them all the credit.
And I do love the Earth—I have since I was a child growing up on the farm. And I love foraging in her “hair” for wild edibles and, in the process, grooming the invasive plants off her scalp. I love the wildflowers that spring up every year far more than I love flowers I plant myself. I love these trees that surround me, indulging my presence.
It’s all about love, justice, and truth, which I am passionate about. Perhaps Gaia needs more people like us, as well as like Jon. I believe there are many more people like us than there were even a decade ago, and that there will be many more among our children and grandchildren. People who love the Earth and try to do well by her without thinking twice about it.
By Nancy Myers
Matt Damon is starring in a new movie to be made about fracking, The Promised Land. Of course, there was the powerful documentary, Gasland, whose maker, Joshua Fox, was arrested trying to film a House Science Committee hearing on fracking for a sequel to Gasland. Another documentary is in the works, Frack Nation, which will apparently extol the benefits of fracking. I can’t wait to see that. Such an inspiring title. (Could it possibly be a spoof? Apparently not.) So the topic of fracking is getting some media attention, at least in film.
We thought something was missing, however–the cartoon version. Perhaps you don’t need to sit for two hours in a movie theater or in front of your TV to learn all you need to know about fracking. Perhaps 4 minutes is enough, including time for laughter. We thought SEHN’s newest colleagues, Stick Girl and Stick Guy, might be able to handle that assignment.
So here is Stick Girl and Stick Guy’s discussion of the 5-letter F word. Tell us what you think.
And here’s SEHN board member Sandra Steingraber’s latest take on the issue, “Cancer in the Ransom Note,” which won’t take you more than 4 minutes to read and packs an even more powerful punch.
If you want to do something about fracking, one place to start is by supporting the New York coalition that is trying to keep their state from going the way of Pennsylvania. Sandra helped get that coalition going.
Much more can be done. Stick Guy points out that we need to ramp up efficiency and conservation. And wouldn’t it be great if the federal government actually decided that fracking should be regulated under existing laws such as the Clean Water Act? It’s been given a total pass, left to the states. What a mess. Literally.
By Katie Silberman
The New York Times recently ran a piece titled “Is It Safe to Play Yet?”, with the puzzling subtitle: “Going to Extreme Lengths to Purge Household Toxins.” Puzzling because, instead of focusing on the very real health threats to children from exposures to toxic chemicals (cancer, asthma, learning disabilities and more), the writer uses the “neurotic mommy” trope to frame his piece.
Let’s imagine for a moment that a dad saw a danger to his child and removed it (caught a ball that was hurtling towards her head, say). He would be called heroic, not neurotic. Why is it okay to ridicule women for the same action?
In fact, the article itself points out why women do have to act in our own homes: government regulation of harmful chemicals in everyday products is basically non-existent. We’re surrounded by endocrine disruptors in canned food, carcinogens in bubble bath, and neurotoxins in toys. And exposures to children are even more alarming, since children’s bodies are more vulnerable to the harmful effects of such chemicals.
So with government regulators MIA, it’s up to us to address this problem. But creating an (impossible) non-toxic bubble in our homes or shopping our way out of the problem (the Times piece cites a $400 bassinet) isn’t going to do it. We need real policy reform, on the federal level, to force chemical manufacturers to clean up their act.
And that’s where the profound power of all of these “neurotic mommies” comes in. Thousands of women, from Alaska to Alabama, have banded together in organizations large and small. The national Safer Chemicals Healthy Families campaign serves as an umbrella coalition, amplifying our voice on Capitol Hill and making sure that Congress hears our demand for change. Twice last year, groups of families held “Stroller Brigades for Safer Chemicals,” literally marching in the streets to demonstrate the need for reform. We are educated and passionate about the issue, politically organized and active, and working on both the local and federal levels: that hardly sounds neurotic to me.
But women who have stood up for social change have been derided as neurotic and hysterical for as long as there have been social change movements. The 19th century activist Fanny Wright, who fought for the abolition of slavery and free public education for all, saw her supporters called “poor and deluded followers of a crazy atheistical woman.”
And yet, here we are in 2012 with the same tired old reaction. Somehow, The New York Times ridiculing women for protecting our kids resonates with the recent political discourse around contraception – when we take care of our families and act in self-determination, the ad hominem attacks start again.
Nonetheless, as women from Fanny Wright to Sandra Fluke have shown, standing up for truth carries its own unassailable power. And really, who’s crazier: women who don’t want our kids bathing in carcinogens, or the chemical industry and its pet legislators, who fight hard to ensure that they will?
Katie Silberman is Associate Director of the Science and Environmental Health Network (www.sehn.org). She lives in Providence, RI with her husband and two little boys.
By Carolyn Raffensperger
Fukushima, Love Canal, Hanford Washington, Chernobyl, Bhobal. These names represent catastrophes that will linger torpid and toxic for thousands of years. Recently I added another name to this list, the Canadian Giant Mine in Yellowknife, Northwest Territories.
A year ago I was invited to draft the principles of perpetual care for the Giant Mine, an abandoned gold mine up near the Arctic Circle. The mine is appropriately named “Giant” because of its size and the scale of its toxicity. It could just as easily be called the Toxic Forever Mine with its 237,000 tons of arsenic trioxide that was blown back into the vast caverns below the surface of the Earth.
The questions that the idea of perpetual care raises challenge human conceptions of time since these sites will be hazardous beyond the range of human memory. Sites like the WIPP site in New Mexico contain radioactive materials that will be hazardous for 250,000 years or 10,000 generations. How do we warn generations that far into the future? How do we protect them? What do they need to know? By what right do we leave a legacy to the future beings that they will have to pay for and that is so toxic?
It would be so easy to forget the Giant Mine. It is far away and the local human population nearby is small. But the Giant Mine holds a story that contains a moral. It tells us the consequences of heedless greed. It is a warning in and of itself: gut the land and you gut yourself. Simply saying the words, Giant Mine or Fukushima invokes an entire history of technology, of place, of human insanity.
The Western Apache, a tribe in the desert southwest of the U.S., tell history in a remarkable way. History isn’t about time, it is about space. They can name a place and simply by naming it conjure the entire story that happened there. The story has a moral with it. The stories tell us how we should live. The Apache say that wisdom sits in places. They aren’t unique in telling history through place names. Vine Deloria says that most American tribes hold “spatial conceptions of history”. Keith Basso, author of the book Wisdom Sits in Places says, “For Indian men and women, the past lies embedded in features of the earth—in canyons and lakes, mountains and arroyos, rocks and vacant fields—which together endow their lands with multiple forms of significance that reach into their lives and shape the way they think.” Pg 34
Basso, quoting N. Scott Momaday says that “men and women learn to appropriate their landscapes, to think and act “with” them as well as about and upon them…” Basso goes on to say that the challenge is “to fathom what it is that a particular landscape, filled to brimming with past and present significance can be called upon to “say,” and what, through the saying, it can be called upon to “do.” Pg 75.
It is our task, I believe, as environmentalists to tell stories of places that allow wisdom to sit in those places. What have we learned from Chernobyl and Love Canal? Can we transform the story of the Giant Mine into a story that takes the great tragedy of that place and all the deaths, contaminated water and destruction that arose from gold mining and make it so that wisdom sits there?
I imagine how we would tell the story of the Giant Mine to the great grandchildren of the great grandchildren as a wisdom tale. Imagine that we cleaned up the Giant Mine so the water runs clean. The animals and plants are healthy and the human community thrives. Imagine that we told the story of gold mining and tearing apart the land and lives, poisoned everything around. And then we gave the ending. We learned. We know better. We restored the Giant Mine to health. We could be beloved ancestors. Wisdom would sit in that place.
By Nancy Myers
If the grandchildren of my granddaughter and her second cousins one day make maple syrup in a small patch of woods in northern Indiana, we will have carried on a family tradition for seven generations. It seems possible.
If you have done a thing you love for five generations, then you can surely do it for seven, or more, if someone in every generation takes responsibility. Someone must be the perpetrator. Someone must be the caretaker, the guardian.
In my family the maple syrup tradition started with my Amish grandfather, Tobias T. Eash. The patch of woods belonged to him, then to our father, and now to my brother Loren. My older brothers remember how Grandpa Eash used to boil sap in a crude setup in an outbuilding on his farm a short distance from the wooded acreage. All I remember is Grandma Eash’s maple taffy, so sweet it almost made your teeth fall out just to bite into it. This is where the love began.
We all remember coming over to the sap shack our dad built in the woods itself when we were children. He installed a proper wood-fired evaporator but it was also a crude setup, the dirt-floored shack. We would come over after school to help empty the sap buckets into the tank pulled by a small tractor over increasingly muddy tracks. Then Mom, who always tended the fire, would open the fire door and roast hot dogs in the inferno. Or we would make a bonfire outside. The hunger, the chill, the burned salty dogs, the mud, and, wafting through it all, the maple-scented steam: these anchored the drab days of early March in our family year as firmly as Christmas and Easter.
Although we lived on a farm and worked a lot together, making maple syrup was the only thing we all really loved doing together. The rest of it was just work. Chores. Production—not fun. Perhaps we could have made it fun but that was not in our parents’ nature. But making maple syrup was entirely frivolous, unnecessary work. All it produced was way more maple syrup than we needed. I got tired of maple syrup when I was a kid but I never got tired of the spring ritual.
After the shack was destroyed in a fire the woods stood empty for many years. Mom and Dad passed away. And then, not long ago, Loren took possession of the stand of maples and built a sap shack in it. The setup was better than the old system, but not too much better. Crudeness is part of the flavor of real maple syrup. He enlisted brother Dale, who lives nearby, to help him renew the tradition. And there are usually members of the fourth and fifth generation on hand to get in on the fun.
And so it seems possible that we could carry on this tradition for seven generations. What would it take, though, for this legacy of sweetness to endure to the 10,000th generation? I do not pull this outlandish figure out of my hat. 250,000 years is the duration of certain radioactive elements and certain substances like arsenic, which are concentrated, perpetrated, and left behind by human activities like power generation and mining.
Maple syrup and arsenic. As forthright a representation of good and evil as you can imagine. One is carried on by love and the other is a legacy of a whole collection of love’s opposites—heedlessness, ignorance, greed.
To reclaim, restore, and protect the earth; to prevent more 10,000-generation legacies of poison seems like a huge task. Perhaps the only way to take it on is to break it down into small acts. Designate the guardians and the caretakers. Make it fun. Pass it down, and down, and down. Pass the love down, too, because the love will multiply the deeds.
By Carolyn Raffensperger
Oh the dark hole of environmental despair. The news these days is rarely good. Another fracking approved. Another species lost. Another cancer diagnosed in a beloved. Another day preternaturally warm. It seems that the only music we hear is the requiem.
Over the past year I have participated in many conversations about hope. They usually begin with a quiet plaintive voice from an ally who has faced the reality of climate change or the disasters of Fukushima or logging in the rain forest. That lone voice confesses to having lost hope
I am not optimistic about the future. But like Vaclav Havel, the writer and former president of Czechoslovakia, I believe that hope is not optimism or the belief that everything will turn out all right. Hope it is the deep orientation of the soul towards what is right.
Vaclav Havel’s view of hope is hope with a shadow. We give up illusions and take our place shoulder to shoulder with others so we can all put our weight behind the life-line. How do we hang on during those days when it seems that we will certainly lose and there is no possibility to pull the Earth and the future out of the catastrophe?
In those darkest moments it is not hope we need, it is something more ineffable. It is grace. Grace is that unexpected and undeserved good gift. It is the offspring of love and action. Grace is the little match lit in the dark of night that shows the way out of the dead end. It is the unpredictable tipping point of all of our actions on behalf of the Earth and future generations. We do not know which action will cause the Great Turning, but time and time again we see the plot twist that could only be called grace.
In the end grace is the fuel for hope. We know that we are not alone. We have the strength to keep that compass pointed due north.
By Ted Schettler MD, MPH
Vitamin D plays an essential role in a number of biologic processes throughout the body. In addition to its long-recognized importance for bone health, vitamin D deficiency is increasingly acknowledged to be associated with a number of other diseases and disorders, including various kinds of cancer. A recently published study adds considerable support to yet another health impact—earlier age of menarche in otherwise healthy girls. If this finding holds up in future studies, the implications are profound.
If sunlight exposure is sufficient, adequate amounts of vitamin D are synthesized in the body. But many people, particularly those living in higher latitudes, are not exposed to enough sunlight to generate adequate stores. And, even in sunny places, skin cancer concerns limit sun exposure. Therefore some foods are fortified with modest amounts of vitamin D in an attempt to address the deficiency. Nonetheless, vitamin D insufficiency remains common in the general population. A recent report from the Institute of Medicine addressing this is available here: http://www.ncbi.nlm.nih.gov/books/NBK56070/
Previous studies reported earlier menarche in girls who live increasing distances from the equator, up to about 45-50 degrees latitude. Since vitamin D status is significantly sunshine dependent, vitamin D insufficiency has been proposed as one explanation. But these ecologic, observational studies are inherently limited and best suited to hypothesis generation. However, the more recent study measured vitamin D levels in a group of girls living in a single city before they experienced menarche and followed them for more than two years. It adds important new data.
This study was published in the October, 2011 issue of The American Journal of Clinical Nutrition. It was a prospective, longitudinal study of 242 girls in Bogota, Columbia whose average age at baseline was 8.8 years when plasma vitamin D (25(OH)D) was measured. They were followed for an average of 30 months and periodically asked about the occurrence and date of menarche.
Fifty-seven percent of the girls who were vitamin D deficient (<50 nmol/L) reached menarche during the follow-up period compared to just 23% of those who had sufficient levels of vitamin D (>75 nmol/L). The average age of menarche in these two groups was 11.8 yrs and 12.6 yrs, respectively. These findings held up after adjustment for age and BMI, so that the results could not be explained by overweight or obesity. The authors concluded that inadequate levels of vitamin D were highly significantly associated with earlier menarche in this group of girls. The biologic mechanisms that might explain this remain speculative.
These findings are likely to have extremely important public health and research implications—particularly if they hold up in studies of larger populations.
1) If there is a causal relationship between inadequate vitamin D status and earlier age of menarche, it’s yet another reason to do more about widespread vitamin D deficiency in the general population. In this study, just 11.6% of girls were vitamin D–deficient. For comparison, other studies show that 52% of Hispanic and African-American teens in Boston are vitamin D deficient, and a small sample of white pre-teen girls in Maine showed a 48% deficiency with at least one level of 25(OH)D below 50 nmol/L over a three-year period. (Sullivan, J Am Diet Assoc. 2005;105:971-974)
2) Among the various kinds of cancer linked to low vitamin D levels, the evidence for increased risk of colorectal cancer is probably the strongest and most consistent. However, a link to breast cancer is sometimes although not always observed. A number of laboratory studies show that vitamin D can inhibit cellular proliferation and promote programmed cell death (apoptosis) and cellular differentiation in breast tissue. Laboratory rodents fed low levels of vitamin D develop more mammary tumors when exposed to a carcinogen than animals fed adequate amounts. The effect is most marked in animals that are also fed a high-fat diet. It appears that vitamin D can inhibit both early and later events in mammary tumor development.
In addition, adequate amounts of vitamin D are necessary for normal mammary gland development. For example, in mammary gland organ culture studies, vitamin D–like compounds inhibit estrogen-induced ductal proliferation and branching. This suggests that vitamin D status in pre-pubertal and pubertal girls could influence breast development and, thereby, breast cancer risk.
Epidemiologic studies virtually always look for associations between adult vitamin D status and breast cancer risk. None has attempted to study the influence of childhood vitamin D status on later breast cancer risk. This would of course be difficult to do and would require decades of data collection.
Thus, although laboratory and epidemiologic data confirm the plausibility of a causal connection between inadequate vitamin D and increased breast cancer risk, considerable uncertainty remains.
3) Collectively, these observations raise an additional question—one having to do with research study design and statistical analyses. Epidemiologic studies examining the relationship between vitamin D status and breast cancer risk usually “control for” age of menarche, since earlier menarche is itself associated with increased breast cancer risk. But this recent study suggests that controlling for age at menarche may not always be appropriate. If childhood vitamin D status influences age of menarche, it could thereby influence breast cancer risk. In general, variables within a causal pathway of an exposure-outcome of interest should not be controlled. In the recent IOM report Breast Cancer and the Environment: A Life Course Approach the committee said:
Moreover, confounders need to be understood as operating, not one-by-one, but rather in a complex network of causal relationships. Graphical tools, such as directed acyclic graphs (DAGs), are sometimes used to identify the appropriate confounders for control, and to identify which factors should not be controlled (Greenland et al., 1999; Hernan et al., 2002). This latter group consists of two categories of variables: (1) factors that are downstream of the exposure, and (2) factors that block a pathway between exposure and disease (e.g., they have antecedents, one that is associated with exposure and the other with disease). Some factors that are downstream of exposure may be intermediates on a causal pathway, but whether they are or not, control for them can introduce bias, except in very specific circumstances (Petersen et al., 2006). In most instances, factors that block an exposure–disease pathway should also not be controlled, in order to obtain unbiased measures of the association of interest.
Thus, in future studies of vitamin D and breast cancer risk, consideration will need to be given to a) childhood as well as adult levels of vitamin D and b) whether or not to control for age at menarche when that variable may be influenced by the exposure of interest (vitamin D status).
In summary, we can add earlier age of menarche to the list of potential health impacts that may be caused by inadequate levels of vitamin D—a common condition in the general population. This finding should be verified in a larger prospective study. The public health implications should not be underestimated.
For those who are interested, the Institute of Medicine report finds the evidence for many of the vitamin D–health endpoints, including breast cancer, insufficient to use for determining a recommended daily intake. But for those health endpoints with consistent, strong evidence here is their recommendation:
Recommended daily allowance (RDA) 600 IU daily, except 800 IU daily for men and women > 70 yrs of age;
Safe upper limit (UL): 1000-1500 IU infants; 2500-3000 IU children; 4000 IU adolescents and adults
The IOM report estimates that the average vitamin D intake for males in the US is 300-400 IU daily; for females 200-400 IU daily (varies with age; does not account for vitamin D from sun exposure). Thus, on average, vitamin D intake in the US is well below the RDA of 600 IU daily and well below the estimated safe upper limit.
By Carolyn Raffensperger
There is a lot of good writing on the precautionary principle appearing in academic journals. I should know, I am asked to peer review a lot of it. But there is one consistent mistake made in these articles. The authors focus their attention (and angst) on the definition of the precautionary principle. Many critics of precaution declare that all the different definitions of the principle render it meaningless or incomprehensible. What the critics and supporters of the principle miss when they limit their attention to the definition is that the precautionary principle is not self-implementing. There is nothing in the definition that tells you how to carry it out.
The two most commons definitions are the Rio Declaration and the Wingspread Definition. They are as follows:
Rio Declaration Principle 15
In order to protect the environment, the precautionary approach shall be widely applied by States according to their capabilities. Where there are threats of serious or irreversible damage, lack of full scientific certainty shall not be used as a reason for postponing cost-effective measures to prevent environmental degradation.
When an activity raises threats of harm to human health or the environment, precautionary measures should be taken even if some cause and effect relationships are not fully established scientifically.
There are clear differences between these two definitions and the many others that are part of treaties, laws and policies around the world. Rio is stated passively and negatively: uncertainty shouldn’t be a reason to block action. Wingspread is stated actively and positively: precautionary measures should be taken when an activity raises threats of harm.
No matter what the differences are in the definitions, every single definition contains the same three elements—threats of harm, uncertainty and precautionary action. The beauty and power of the precautionary principle is that it is under-determined and fractal. By this I mean that it can apply to any environmental or public health issue and it can apply at any scale–from GMOs to nuclear power to climate change and from the international scale to choices made in your own home. But the fact that it is under-determined is what gives most critics heartburn. The definitions don’t tell you what to do.
I was one of the conveners of the Wingspread Conference in 1998, which was held specifically to design the steps to implement the precautionary principle. Over the past 13+ years we’ve identified 5 key elements to precautionary action. They are: heeding early warnings, setting goals, identifying and choosing the best alternatives, reversing the burden of proof, and engaging all stakeholders in democratic decision-making.
These steps are complete enough that they provide clear guidance to decision-makers. After all of these years and all the experiments with the precautionary principle, it is clear that we can stop arguing about the definitions and get on with the real work of taking precautionary action to prevent harm even when the science is uncertain.