We narrowly escaped another endocrine disruptor being added to our
midst, but a look around us proves our surroundings are filled with
such chemicals, and they are hurting us in myriad ways.
By Leigh Davis
DEP Rules Against Dimilin Use | A Crash Course in Endocrine Disruptors | The Role of Weight and Sexual Development | Chemical Body Burdens & Chemical Trespass | What Does the Research Say? | The Toxic Soup That Surrounds Us
SEE ALSO: Seventy Years of Endocrine Disruption
printer friendly | add to del.icio.us | e-mail the editors
Here’s a riddle for you: What do weight obsessions, diabetes, precocious puberty, small penises, and gypsy moths all have in common? The answer to this riddle is one of those “what you don’t know can hurt you” stories -- and a detective tale to boot. So maybe it’s best to cut to the chase first, then go back and fill in the linkages.
New Jersey environmental groups scored a win in January when the state
Department of Environmental Protection (DEP) declined a waiver filed by
the state Department of Agriculture (NJDA) to change the way it deals
with gypsy moths. By amending N.J.A.C. 2:23, the NJDA had hoped to allow
spraying of a chemical pesticide intended to inhibit insect growth in
14 New Jersey counties. The pesticide is diflubenzuron, brand-named
Dimilin and manufactured by the Uniroyal Chemical Company.
Since 1985, the state has used a biological pesticide called Bacillus thuringiensis (B.t.) for gypsy moth control. B.t. was chosen after a bitter fight in which environmentalists successfully challenged the use of Seven, a broad-spectrum pesticide with serious human health impacts.
The rationale for the change was an “emergency” due to the large number of gypsy moth egg sacks in both residential and state forest areas that have suffered significant tree defoliation in the past. According to the NJDA’s Joe Zoltowski, without the change these areas could expect 40 to 60 percent tree mortality as a result of multiple defoliations. Yet, according to the NJDA’s own Web site, “…the new dosage rates of B.t. used by the Department of Agriculture provide good foliage protection and population control.”
In a letter to DEP commissioner Lisa Jackson and NJDA secretary Charles Kuperas, 25 environmental organizations expressed their opposition to aerial spraying of Dimilin based on evidence that it could result in negative health impacts on both people and wildlife. Dimilin comes with label restrictions due to its toxicity to water life. One of its breakdown products, p-choloroaniline (PCA), is considered a class B2 (probable) human carcinogen.
On balance, whether Dimilin would even prevent significantly more defoliation than B.t. is unclear, the DEP did not see changing a relatively benign insecticide to something with potential human and wildlife health impacts as justifiable. Nonetheless, this most recent fight, though fairly short-lived, illustrates the continuing need for vigilance against the insidious encroachment of government-sanctioned use of toxic chemicals.
A Crash Course in Endocrine Disruptors
As if the possibility of getting cancer wasn’t enough, Dimilin is also an endocrine (or hormone) disruptor, a class of chemicals that can affect human and animal endocrine systems.
In the case of Dimilin, its endocrine-disrupting properties are what make it attractive for killing insects. It interferes with the development of chitin, which is the building block of an insect’s shell. As an insect grows, it sheds its shell and develops a new one. If it is unable to make a new shell, it will die.
According to Jane Nogaki, coordinator of pesticide programs with the New Jersey Environmental Federation, a branch of Clean Water Action, the EPA has found that Dimilin not only decreased testosterone in birds, but also that “repeated and prolonged exposure” can cause methemoglobinemia, or “blue baby syndrome.” In this condition, the hemoglobin molecule cannot effectively carry oxygen to the body’s tissues.
“The fact that something is reported to be an endocrine disruptor doesn't automatically mean EPA will ban its use,” Nogaki says. “The EPA has been relatively silent on endocrine disruptors. They haven't made any regulations.”
This can, in part, be chalked up to the fact that hormone disruptors do not operate in the same way as other direct toxic impacts. The effects are indirect; these chemicals either mimick or interfere with hormones native to our bodies.
A 2001 report (PDF file) in Environmental Health Perspectives said that endocrine disruptors “are among the most complex environmental health threats known today.” The report found that endocrine disruptors have a “non-monotonic” dose-response relationship. In other words, effects grow as the dose is reduced, which flies in the face of classic toxicology’s standard assumption that lower doses mean less – and at some point, no – effect.
Our hormones are the chemical messengers of our bodies and they influence all of our bodily processes -- reproductive, developmental, neurologic, metabolic, and immune – and thus, chemicals that interact with the endocrine system can result in a range of physical effects. Yet more often than not, we don’t make the connection between what is happening in our body and the effects of synthetic chemicals.
The Role of Weight and Sexual Development
According to the American Obesity Association, we spend $30 billion a year on diet products. In 2000, liposuction became the leading cosmetic surgery in the United States, with 440,000 operations a year. We are clearly not comfortable with our bodies and appear to be working hard at keeping the weight off.
However, we’re also tipping the scales, and in New Jersey the statistics are ominous. In 2004, according to the Center for Health Statistics, 37 percent of us could be classified as overweight, with another 22 percent considered obese. More than half of us are at risk for developing health problems related to being overweight. Those health problems include cardiovascular disease, hypertension, and even cancer (almost half of all breast cancer cases are in obese women, for example).
Among New Jersey kids in ninth through twelfth grade, 12 percent are overweight, and 15 percent are at risk for becoming overweight. (This is double the number of just 20 years ago.) The younger the age group, the worse the problem is: Among sixth graders, 18 percent are overweight, and 20 percent obese.
Research has shown that overweight kids tend to grow up to be overweight adults and are at risk for type 2 diabetes. Many adolescents and children have blood glucose levels that put them at risk for diabetes as they reach adulthood. The CDC suggests that “the magnitude of diabetes [in children] is probably underestimated.” The medical news today is that as a result of the diabetes and obesity epidemics, for the first time in modern history, kids will not live as long as their parents.
Some folks have noticed that young girls seem to be hitting puberty younger and younger. But is that true? Maybe we’ve forgotten at what age it’s appropriate to develop breasts or begin menstruating. In previous generations, one out of 100 8-year-old girls was reaching puberty. Today, it’s one in six.
A 1997 study by University of North Carolina researcher Marcia Hermann-Giddens found not only that girls were showing signs of breast development and pubic hair by age 3, but that almost 50 percent of black girls had reached puberty by age 8.
Boys, too, are showing signs of reaching puberty at younger ages, with some as young as 8 years old showing mature genital development.
Some researchers are suggesting that reaching puberty by age 7 is not unreasonable. Or they’re calling it “idiopathic,” meaning that they can’t find a reason for it. Doctors are telling themselves and parents that their previous beliefs about what was normal were simply wrong and that they just need to adjust the range of normal downward. But why is this adjustment necessary?
What they’re forgetting is the demonstrated relationship between earlier puberty and increased risk of prostate cancer in men and breast cancer in women. So as more children hit puberty at younger and younger ages, we can expect an increase in these cancers in their adulthoods. The lifespan of this younger generation takes another hit.
Still another development: More infant boys are being born with undescended testicles, smaller penises, “feminized” genitals (shortened anogenital distance), and hypospadia (a birth defect in which the urethra does not extend to the end of the penis). All of these defects are what you would expect if something -- an endocrine disruptor, perhaps -- was interfering with testosterone during prenatal development.
The runaway incidence of such neurological problems as autism spectrum disorders -- legion in New Jersey, where Brick Township had the distinction of being the first official autism cluster in the nation -- as well as attention deficit hyperactivity syndrome and learning disabilities may also be connected to the cumulative and synergistic effects of exposure to low-dose endocrine disruptors. However, as the folks in Brick have learned, the dicey ways in which endocrine disruptors behave make proving any such connections elusive.
Chemical Body Burdens & Chemical Trespass
Just under the public radar, there is a growing concern among researchers that something is going terribly awry in our bodies. That something is tied to what is called our “chemical body burden.” The term refers to the amount of human-created chemicals we carry in our bodily tissues. Scientists have found as many as 700 synthetic chemicals in human fat tissue, and up to 500 chemicals in the blood and urine of average people.
The Pesticide Action Network of North America coined the term “chemical trespass,” to describe the existence of industrial chemicals and pesticides in our body tissues. Their research (PDF file) has shown that those most vulnerable to chemical trespass are women, children and Mexican-Americans. They cite CDC data showing that “the average 6- to 11-year-old sampled is exposed to the organophosphorous pesticide chlorpyrifos (commonly known by the product name Dursban) at four times the level the U.S. Environmental Protection Agency considers ‘acceptable’ for a long-term exposure.” Dursban is an endocrine disruptor.
“Pesticides” refer not just to the chemicals we use to kill household pests such as cockroaches and ants, but also to herbicides, used in farming and on golf courses and lawns to control weeds. Herbicides such as atrazine -- manufactured by the agribusiness company Syngenta, a hybrid of Big Pharma giants Novartis and Zeneca -- have become a focus of concern. One reason is that many pesticides, which are often the byproduct of petroleum refining, are persistent organophosphates (POPs). The emphasis here is on persistent -- they cannot be broken down in the environment, so they persist. They also concentrate as they move up the food chain.
We encounter pesticides in myriad environments on a daily basis -- through our use of home and garden pesticides, use by residential and commercial landscapers and groundskeepers, and in our food and water as a result of agricultural use.
Other suspected endocrine disruptors include phthalates and adipates, known as “plasticizers” because they make your plastics flexible. These line the inside of cans of food or are part of the bottle your spring water comes in. They’re in intravenous bags, your child’s rubber ducky toy, the cosmetics in your medicine cabinet, or possibly in your shampoo. Because they persist in the environment and tend to accumulate in fat, they turn up in fatty food, as well as fish caught in contaminated water.
Research has implicated bisphenol A, an endocrine disrupting chemical used in the plastic lining in food cans, baby bottles, plastic tableware, composite dental sealants, flame retardants, adhesives and a host of other plastics and resins, in the increase in obesity and diabetes as well as advanced puberty. Among the studies:
• A study published in the January 2006 issue of Environmental Health Perspectives found that bisphenol A disrupts pancreatic beta-cell function, resulting in insulin resistance and leading to diabetes.
Exposure to pesticides, phthalates, and flame retardants has been implicated in precocious puberty. For instance:
• In 2000, a study of 8-year-old girls in Puerto Rico found high levels of phthalates in more than two thirds of girls who had premature breast development. Puerto Rico has the highest known incidence of premature breast development.
Phthalates have been implicated in the increase in genital birth defects in boys, to the point where those defects have been labeled “phthalate syndrome.”
• A 2005 study found a relationship between blood levels of three phthalate metabolites (breakdown products) and shortened anogenital distance and penis size. The odds ratio for having a short anogenital index with high phthalate exposure levels was 90 times that of babies with low phthalate exposure levels.
Recently, Theo Colborn, known for her groundbreaking book on endocrine disruptors, Our Stolen Future, compared the data on the growth in the manufacture of synthetic chemicals with the increased prevalence of neurodevelopmental problems.
“It was during the 1970s that what appeared to be increases in unusual, previously rare neurodevelopmental disorders began to catch the attention of health professionals,” Colborn says. “[That’s when] the first generation of humans exposed in the womb to synthetic chemicals on a large scale began to have children of their own.”
Colborn doesn’t just cite research that shows increases in depression, bipolar disorder, suicides, attention deficit hyperactivity disorder, and autistic spectrum disorders in each subsequent birth cohort. She also describes the likely mechanisms of action of hormone-disrupting chemicals, including their effect prenatally on thyroid hormones, which are involved in neurological development.
The Toxic Soup That Surrounds Us
So, these chemicals are all around us and even inside our bodies. Mothers are passing them on to their unborn children. What’s one more pesticide to take care of the gypsy moths? It might seem like a one-time aerial spraying wouldn’t be all that much.
But wouldn’t it?
“In April through June, we see a significant increase in pesticide use throughout the state,” the New Jersey Environmental Federation’s Nogaki points out. “People are putting pesticides on their lawns, farms are doing aerial spraying on their crops. Do we really want to add to that?”
Indeed, shouldn’t we be paying more attention to those little yellow flags that pop up on lawns and other grassy areas in our neighborhoods come spring telling us to keep our pets and kids away? Is putting a plastic lock on our undersink cabinets enough to truly “childproof” our homes?
We could say that no one knows the cumulative impact of all these “low-dose” sources of hundreds of chemicals. But we do. We are seeing it all around us in larger people, more diabetes, larger adolescent breasts, smaller and deformed penises, increased rates of breast and prostate cancer, effects on our immune and neurologic systems and those of our children, and a host of chronic illnesses that are sending our national health care costs through the roof.
Folks in New Jersey may have dodged Dimilin’s chemical bullet, but what of the others with which we come into contact daily? At what point – and how -- do we post a “No Trespassing” sign?
We are both fragile and adaptive. But can we adapt to corporate recklessness?
I wish more people would read this article, filled with critically important information.
Thanks Leigh!
Posted by: Anna Jacus | 02/22/2007 at 02:30 PM