herbicide hormone havoc

The Washington Post is reporting on yet another study that shows that the widely-used herbicide, Atrazine, scrambles hormones in wildlife.

In this study, Dr. Tyrone Hayes at UC-Berkeley found that male frogs who as tadpoles swam in water tainted with low levels of Atrazine (within the US EPA's drinking water limits) developed female sex traits. 10% of the male frogs even laid eggs that hatched!

Syngenta, the chemical company that makes Atrazine, continues to stick to their story that Atrazine does no such thing. Every study they've released shows the opposite.

Meanwhile, the US EPA is taking another look at Atrazine, which they re-registered for use in 2006 based on Syngenta's safety data. It seems all this independent research has shown things in a different light. Perhaps EPA will start making a practice of considering independent research - not just the company's own data - when evaluating a pesticide's risks. It would be long overdue.

Research links Pesticides to Autoimmune Disease

Guest post by Toxic Free NC volunteer Amy Freitag.

Yet another reason to question use of pesticides in the home: it has recently been linked to autoimmune disorders such as rheumatoid arthritis and lupus. In a study presented at the American College of Rheumatology’s annual meeting earlier this year, researchers concluded that women who sprayed pesticides at least six times a year doubled their risk of autoimmune disease. This risk was the same whether the pesticide was applied professionally or not. Read the rest of the story here, but that’s not the beginning of the journey nor is it likely to be the end. A review published in 1988 summarized the effects of various chemicals, including pesticides on autoimmune response based on understanding at the time. The field has come a long way since then, but the basic link between the two was pretty well elucidated, even 20 years ago. The authors linked seven different types of autoimmune reactions to chemical exposures and suggested that genetic predisposition may lead some people to be more susceptible to environmental exposures than others.

Autoimmune responses in a nutshell describe the process of the body attacking and destroying healthy and important cells. It’s like sending the baby out with the bathwater, as the saying goes. The signaling pathway within the body that leads to the miscommunication is still not understood, and likely to be different depending on the person and the tissue attacked. Environmental exposures, however, are implicated as triggers. In the intervening twenty years since that first review, a flurry of articles have been published presenting mixed results on the link between chemical exposure and autoimmune response. Depending on the exposure and the target tissue, immune response could increased to unsafe levels, but could also be decreased or left the same. According to a review in 2002, the pesticides malathion, lindane, and aminocarb, cause an autoimmune reaction in both sheep and mice. The authors do caution the use of animal models, as their immune systems may react differently to exposures than humans, but they are the best model we have as scientists.

The only human study done to date involved a spill of the pesticide hexachlorobenzine (HCB) in Turkey, where residents near the spill showed a drastic increase in autoimmune disease. Compared to previous studies on HCB, humans showed a much more sensitive autoimmune response, suggesting that animal models may provide only a conservative estimate of which exposures will show an effect in humans.

Most people are left with this review of the medical literature with their head in a kind of cloud as to what the data are really showing. Since almost all studies show some effect of pesticides on autoimmune responses, the precautionary principle should be invoked. It’s another case of the need to limit exposure to chemicals that may cause devastating disease in the future, because you may be one of the lucky few with genetic resistance to autoimmune disease, but your loved ones might not be.

Even Colbert is getting nervous about endocrine disruptors

guest post by Toxic Free NC volunteer Lowell Wood

A few weeks back I was watching The Colbert Report, when the only anchor I trust to give me the news (Stephen Colbert) sat down with New York Times op-ed columnist Nicholas Kristof. Kristof addressed how the endocrine disrupting chemicals found in pesticides and other agricultural and consumer products are deforming wildlife living in polluted watersheds.

In the video below, Kristof manages to excite Colbert with mention of male genital deformation. Before the interview completely deteriorates into potty humor and genital jokes (like all Colbert's interview inevitably do), Kristof manages to convey the growing concern many environmental scientists have with the abundance of endocrine disruptors.

(Warning: video contains potty humor and genital jokes as referenced above - sensitive audiences please beware!)

The Colbert Report	Mon - Thurs 11:30pm / 10:30c
Nicholas Kristof
www.colbertnation.com
Colbert Report Full Episodes Political Humor Jeff Goldblum

A week prior to Kristof's appearance on the Colbert Report, he published an op-ed column in the New York Times on the same topic. In the article, he discusses a recent scientific statement from The Endocrine Society which cites mounting evidence that endocrine disrupting chemicals are having negative effects on our health, and urges increased precaution. Kristof goes into detail in the article about the chemicals' disruptive effects on reproduction and growth in animals, and the growing evidence that endocrine disruptors are negatively effecting humans as well.

This reminds me of our old friend Tyrone Hayes and his astounding work on hermaphrodism in frogs caused by the herbicide atrazine and other chemical pollutants.

Articles and videos like these underline the importance of environmentally sustainable practices in all fields; whether they be the products we use and interact with daily, or the less visible ones a few steps removed from us, like the pesticides used on the foods we buy. Information like this inspires me to raise awareness about how our actions are harming not only the world around us, but us human beings as well. It also encourages me to use the power I have as a consumer to change these evil ways by purchasing organic goods.

Join me! Watch the video, read the article, take action, and make change! Check out Toxic Free NC's website for ideas to help you get started, or call our office at 919-833-1123 to get more involved.

Environmental Causes of Autism

Rates of autism nationwide have skyrocketed over the past 15 years. Scientific American reported this week on new research coming out of CA finding that chemicals in our environment may be responsible for most of the rise. Which common but easy-to-avoid chemicals are high on those scientists’ list of suspected culprits? Some are things you might guess, and others maybe not.

From the Scientific American article:

"Dozens of chemicals in the environment are neurodevelopmental toxins, which means they alter how the brain grows. Mercury, polychlorinated biphenyls, lead, brominated flame retardants and pesticides are examples.
While exposure to some--such as PCBs--has declined in recent decades, others--including flame retardants used in furniture and electronics, and pyrethroid insecticides--have increased.
Mothers of autistic children were twice as likely to use pet flea shampoos, which contain organophosphates or pyrethroids, according to one study that has not yet been published. Another new study has found a link between autism and phthalates, which are compounds used in vinyl and cosmetics. Other household products such as antibacterial soaps also could have ingredients that harm the brain by changing immune systems, Hertz-Picciotto [the lead researcher in the study] said."

Yikes! Maybe you're a parent or want to be one, or maybe you aren't - either way take heed that these chemicals are at the top of a list of things that are bad for babies' brains, and it stands to reason that they're not great for your brain either. Many of the same chemicals listed here are also linked with increasingly common health problems in adults, like cancer and Parkinson's disease.

So here's your list of stuff to avoid based on this article, and some tips for avoiding them:

* Flame retardants found in furniture or electronics. Tips from Environmental Working Group on avoiding them.

* Pesticides in general, with special caution about pet shampoos and other products that contain organophosphates and pyrethroids. There are lots of ways to avoid these, but I'll share a couple of the most relevant highlights: 1) Eat organic. (It's a perfect time of year to join a CSA - more on that in an upcoming tip!) 2) Use non-toxic methods to get rid of home and garden pests - check out ToxicFreeNC.org for more info, and also my past NewRaleigh posts. And, 3) if you have pets, use least-toxic alternatives to flea shampoo.

* Phthalates, found in vinyl, some cosmetics, and some plastics. Also associated with reproductive system disorders in male children. Augh. Tips for avoiding phthalates from the Pollution in People project.

* Antibacterial soaps, which commonly contain triclosan - actually a pesticide. Did you know that studies have found that regular soap gets just as much bacteria off your hands as antibacterial soap does? Tips for avoiding triclosan in soaps and other antibacterial products.

I'm planning to address each of these chemicals in more depth as part of my "Toxic Free NC Tips of the Week" series for NewRaleigh.com. If there's any in particular that you're keen to learn more about ASAP, please drop me a line.

Noisy spring, silent summer?

This is a story about sludge, worms and songbirds, and it starts in your bathroom cabinet.

When we treat our wastewater to remove "biosolids" -- a polite term for our human waste -- all sorts of other things end up in the leftover sludge, including the drugs we take and the "personal care products" like lotion, shampoo, makeup and cologne that we slather on our bodies, which have been absorbed through our skin and then excreted in our waste. The treated wastewater is usually discharged into the local river, and the sludge that's been removed from it frequently becomes fertilizer for agricultural production.

Researchers at the US Geological Survey have found that the hungry earthworms who feed on this sludge in farm fields contain concentrated levels of our drugs and personal care products in their bodies. In fact, a USGS study published in February found that the compounds bioaccumulate in earthworms, meaning that the worms bear higher levels of these pollutants than the surrounding soil does. The USGS researchers note that worms could become monitoring species to help us determine the relative pollution levels in soil, but state that the pollution in these worms have "unknown effects" for wildlife [read the story in Science News].

"Unknown" maybe in that particular study, but researchers in the UK published a disturbing study about a week later that provides some insight into what happens to the polluted worms: Birds eat them.

This particular study examined Eurpean Starlings in the wild, who like to forage in farm fields where fertilizer from sewage sludge has been applied, because the soil is rich in earthworms and other organisms who are busy feasting on the nutrients in the fertilizer. But they're also feasting on the contaminants in the fertilizer, and those contaminants have an impact on the foraging birds [read the story in the New York Times].

The contaminants in sewage sludge can contain hormone-mimicking compounds that act like estrogen in the birds' bodies (Following the thread here? Those compounds are the drugs and personal care products the USGS was examining in the earlier study).

The UK researchers found that the contaminants boosted development in the part of the male birds' brains that control their songs, making them sing longer and more complex songs. The researchers also found that female starlings preferred the long, complex songs of the contaminated male starlings.

The bad news is... they're contaminated. The same endocrine-disrupting compounds in the male starlings that made them attractive as mates make them unfit as fathers, because the compounds suppress the birds' immune systems and make them sick. While that might be good news for American birders who aren't fond of invasive starlings, it's rather bad news for birds everywhere who like to eat worms. While that fat earthworm might taste good and improve a male songbird's chances of attracting a pretty lady bird, it could actually be crippling his chances of producing a healthy brood of babies.

This might seem like just a scientific curiosity if the same kinds of effects hadn't also been noted in many other species, including fish, reptiles and amphibians. Sort of makes you think twice about that nice body spray in your bathroom cabinet that's supposed to make you more attractive to a mate, doesn't it?

Biofuels - not so hot

I was already a big skeptic of biofuels before today. Using cropland to grow giant monocultures that are then burned as fuel instead of fed to people seems like a not-so-hot idea - think of the pesticides! More mono-cropping means more chemical pesticides and fertilizers that end up harming downwind and downstream communities and ecosystems. Yuck!

Today, I learned that two recent studies confirm that in addition to being a source of pesticide pollution, biofuels aren't actually preventing global warming either. Princeton University and The Marshall Fund published a study in the journal Science, and The Nature Conservancy has put out a study with similar conclusions.

From an article in The Washington Post on these findings:

"(...) As the study from the Nature Conservancy warns, 'converting rainforests, peatlands, savannas, or grasslands to produce biofuels in Brazil, Southeast Asia and the United States creates a 'biofuel carbon debt' by releasing 17 to 420 times more carbon dioxide than the fossil fuels they replace.' There are other negative effects. Massive amounts of water are needed to irrigate cornfields, setting up potential competition between farms and homes. The runoff of pesticides and nitrogen-based fertilizers used by farmers could lead to increased pollution and oxygen-depleted waterways. The natural gas used to make the fertilizer adds to the carbon deficit created by biofuels.

An essay in the May-June 2007 issue of Foreign Affairs by two professors from the University of Minnesota highlighted still another problem: The biofuels craze could starve people. "By putting pressure on global supplies of edible crops, the surge in ethanol production will translate into higher prices for both processed and staple foods around the world," they wrote. "If oil prices remain high -- which is likely -- the people most vulnerable to the price hikes brought on by the biofuel boom will be those in countries that both suffer food deficits and import petroleum."

Will someone please get the memo to decision makers in Washington who are pouring money into biofuels right now?? Eep!

frogs, frogs and fewer frogs

Oh, the beleaguered frogs. You probably already know that amphibian species are declining around the world. You have probably seen the depressing photos of deformed frogs trying to get through life with too many (or too few) legs. You may even have seen Dr. Tyrone Hayes' breathtaking presentation on how the herbicide atrazine turns boy frogs in to hermaphrodite frogs.

This week the N & O ran a story about a new study that reinforces the theory that farm runoff is causing the deformed limbs. Excess nutrients in the water lead to lots more parasites in the water that turn normal tadpoles into sickly, deformed adult frogs.

One of the questions about this research is, how come the trematodes make frogs so sick? They're not a new pathogen - they've always been in the frogs' environments. It's just that lately the frogs can't seem to fight them off. Another stumper: if it's one disease deforming the frogs, why does it affect so many species? Leopard frogs, bullfrogs, wood frogs, and many others have shown up with the deformed limbs, in many different parts of the U.S. and Canada.

The answer may actually lie in the frogs' immune systems: one of Tyrone Hayes' experiments found that wild frogs who live in pristine waters are easily able to fight off common infections, while wild frogs who live in waters containing agricultural runoff die at astonishing rates from the same exposure to disease. Distinguished researchers around the world have pointed at all sorts of explanations for the frog decline, deformities and hermaphrodism: climate change, habitat destruction, parasites, pesticides, and more. The sad answer may be that there is no smoking gun, but that an alphabet soup of environmental changes have over-burdened the frogs' immune systems to the point of destruction. Parasites and infections that formerly posed little or no threat to amphibian populations become deadly.

Biologists like to call frogs a "sentinel species," because they are so sensitive to their environments and serve as indicators for problems that can grow to affect other species as well. I hope we're paying attention.

Toxics: Adding it up

Have you ever kept a food journal? It goes something like this:

Monday

• Breakfast: Glass of OJ, bowl of cheerios with soy milk, black coffee (X calories, X grams of fat).
• Lunch: Microwave burrito (X calories, X grams of fat).
• Afternoon snack: Half a box of Thin Mints Girl Scout cookies...

...you get the idea. I'm stopping before I get to the second afternoon snack. What if we kept toxics journals, that charted our various exposures all day long?

Monday

• Overnight: polybrominated flame retardants (mattress), volatile organic compounds (carpeting).
• 7:00 AM. Shower: Nitrosamines, triclosan (soap), fragrances, methylisothiazolinone, benzoate (shampoo), toxaphene, copper, trihalomethanes (water), 1,4-dioxane (deodorant).
• 7:30 AM. Breakfast: Trisodium phosphate (cereal), plant-based phytoestrogens (soymilk), phthalates (milk container), ethion, carbaryl (orange juice), caffeine, chlorpyrifos (coffee).

...okay, let's stop right there, before we get out onto the highway and have to try to write down all the ingredients in diesel exhaust.

Everybody knows that we are not exposed to chemicals one-by-one, but in a chemical soup, all day long. Congress first tried to get their regulatory minds around this problem with the Food Quality Protection Act, in 1996. The FQPA suggests that kids don't just eat one apple with chlorpyrifos residue in it, but also carrots, peaches, strawberries... so when performing risk assessments for pesticides, EPA should have to consider that the residues might add up.

The problem with that is in the toxicity testing itself. Even though we know that we are exposed to mixtures, we don't test the mixtures for how their toxicity differs from the parent chemicals. We test single chemicals, one-by-one , and our chemical regulations are based on the results of isolated exposures to different levels of isolated chemicals. That's pretty unrealistic.

Here's what happened when Earl Gray, a toxicologist at the EPA's research labs in Research Triangle Park, started adding two fungicides together. Gray's research was featured in a recent article on chemical synergies in New Scientist magazine:

Gray... and his team also tried exposing pregnant rats to vinclozolin and procymidone. When they exposed the animals to the compounds individually, they too saw no effect. But when they combined the two, half of the males were born with hypospadia [a birth defect of the penis]. Gray calls this phenomenon "the new math - zero plus zero equals something".

Gray saw similar results when he mixed two kinds of plastics together - neither of them had any effect when given to pregnant rats on their own, but given together, all the male rat pups were deformed. Believe it or not, he got the same results when he mixed the unrelated plastic and fungicide compounds, which attack the developing organism through totally different mechanisms.

Okay, so we know that mixtures are a problem. So let's get some people together and study the effects. All we need to do is find a group of exposed people, and then an unexposed group, and compare... oh wait. There is no unexposed group. Again, from the New Scientist article:

"Everyone has exposure to chemicals, even people living in the Arctic," says John Sumpter, an ecotoxicologist at Brunel University in London. "We can't go to a group with a mixture of nasty chemicals and then go to another who have had no exposure and compare their rate of breast cancer risk or sperm count. We are doing a scientific experiment by letting these chemicals accumulate in our bodies, blood and wildlife."

So what do we do? Well, here in the U.S., we're mostly still taking the whack-a-mole approach, and regulating troublesome chemicals like flame retardants, lead, and individual pesticides one by one. In Europe, new legislation called REACH went into effect on June 1. REACH stands for registration, evaluation, authorisation and restriction of chemical substances.

The aim [of REACH] is to cut health risks associated with everyday chemicals by forcing chemical manufacturers and importers to register their compounds and provide safety information to the new European Chemicals Agency, based in Helsinki, Finland. This information must be provided before the chemicals are sold. The new law shifts the burden of responsibility for the health effects of chemicals from government to industry and is also intended to encourage the use of less harmful alternatives for the more toxic chemicals.

The REACH legislation is a whole new approach to chemicals regulation. Unlike the "innocent until proven guilty" approach that we use in the U.S., REACH makes manufacturers prove safety before letting these chemicals out the door. It's based on a concept called the Precautionary Principle. Look before you leap. Better safe than sorry. You get the idea.

REACH isn't the whole solution, but it's a powerful regulatory incentive for manufacturers to start phasing out the worst chemicals, and to find safer solutions. Many of us work hard to limit our own exposures to potentially harmful toxics in any way that we can - but we have to rely on government to control the toxics pouring out of smokestacks, tailpipes and products that we can't control.

It will take a tremendous amount of expensive research to understand exactly how all the toxics we're exposed to all day long affect us when they're mixed together, and who is most vulnerable to long-term harm. The regulators have a choice: they can sit back and wait until the results are in, or they can heed the red flags we see now and take precautionary action. The REACH legislation took option #2. It's up to us to decide how the U.S. will act.

Go organic to fight global warming!

Need another reason to buy organic food?

According to findings from the ongoing Farming Systems Trial at The Rodale Institute, organic grain farming, including low- or no-till soil preparation and cover cropping, actually increases carbon sequestration in the soil by 15% - 28% compared with conventional farming techniques. Translation: 15% - 28% percent less carbon dioxide goes into the atmosphere because it's bound up in the soil. This is in addition to reduced carbon dioxide emissions from farm equipment on organic farms (no-till means fewer passes over the field with a gas-guzzling tractor and about one-third less carbon emissions), and from the production of petroleum-based fertilizers. Add to that buying local AND organic, and you eliminate still more greenhouse gas production from food transport. Wow!

So what does carbon sequestration mean, and why do organic farms have more of it? Well, the folks at Rodale have a couple explanations:

One is that organic cultivation focuses on building up carbon-based organic matter, or humus, in the soil. Humus refines soil texture and holds nutrients and water. Soil rich in humus is more naturally fertile, and holds a more consistent level of moisture, even in the face of heavy rains or drought. Plus, humus is made of carbon! On a conventional farm, application of nitrogen-rich chemical fertilizer stimulates soil organisms to break down any humus in the soil very quickly, and when they do, they release carbon dioxide into the atmosphere. On an organic farm, humus is added to the soil and breaks down very slowly, so it feeds the plants over a long period of time, AND releases much less carbon dioxide.

Another reason has to do with mychorrhizae - microbial fungi that are naturally present in organic soil. These mychorrhizae actually work symbiotically with plant roots, helping them to take up more water and nutrients from the soil in exchange for a 12% share of the (carbon-based) energy that the plants make using photosynthesis. This means that plants working together with mychorrhizae are doing more photosynthesis and fixing more carbon dioxide from the atmosphere into the soil, in addition to being healthier and more disease resistant. Synthetic fertilizers and pesticides used in a conventional farming system actually kill off some of the mychorrhizae and stop this symbiotic carbon sequestration from occurring.

But how much greenhouse gas are we talking here? Is this enough to put a real dent in global warming? Here are some numbers to put this into perspective:

If all 160 million acres of corn and soy grown in the US were transitioned to organic, they'd be sequestering about 580 billion extra pounds of carbon dioxide per year. That's like taking 58.7 million cars off the road, or about 25% of the cars in the US. Yow! If ALL American cropland went organic, it'd be like taking more than half the cars in the US off the road.

Check out this video (starring Percy Schmeiser) about the Rodale findings, and be sure to add "eat organic food" to your list to-dos for reducing your carbon footprint, right up there next to compact flourescent lightbulbs, carpooling, or riding your bike!

Hormone havoc - this is news?

With some fanfare, the US EPA announced this week that it will begin screening 73 popular agricultural & residential pesticides to find out whether they might be endocrine disruptors. The screening would be the initial phase of a multi-stage review that would not consider new restrictions on pesticides until after many exhaustive rounds of testing.

What's an endocrine disruptor? It's a chemical pollutant that, at low levels, can mimic hormones in the human body. This is problematic when the pollutant plugs into our body's hormone receptors during key phases of human development, blocking or scrambling the developmental signal that the hormone should have been sending. The scrambled signal can result in long-term health problems - in lab animals, effects like feminized males, hermaphrodite offspring, low sperm counts and sterility. Endocrine disruption is also being studied as a mechanism in the development of cancer.

We've been hearing a lot about endocrine disruptors ever since the groundbreaking 1996 book, Our Stolen Future, introduced them to a general audience. In 1997, Congress ordered the US EPA to begin looking at whether the thousands of pesticide products it reviews and registers each year might be interfering with the endocrine system. Ten years and tens of thousands of new pesticides later, EPA is finally making a list: 73 chemicals to be reviewed.

Given all that independent researchers have already discovered about endocrine disruptors, and all the red flags that two decades of studies have already sent up about specific pesticides, EPA seems a little behind the curve here. There's already plenty of evidence to warrant their consideration of new restrictions on several chemicals like atrazine, which has been shown to turn male frogs into females at stunningly low doses.

Considering the long-term implications for human (and wildlife) health, it seems absurd that EPA has taken so long to even begin looking at this critical phenomenon. Though I'm sure the pesticide industry has been happier while EPA simply looked the other way.

Blue frogs

Though not actually blue in color (unless they're one of these guys), frogs everywhere are apt to be feeling a bit blue upon hearing last week's news that three widely used organophosphate pesticides (or "OPs") have been found to be even more toxic to frogs than was previously thought.

In a study published last week in the journal Environmental Pollution, scientists at the University of Southern Illinois, Carbondale and the U.S. Geological Survey report that the breakdown products of insecticides diazinon, chlorpyrifos, and malathion are far more toxic to certain native California species of amphibians than the original pesticide chemicals, which are already highly toxic. In other words, these highly poisonous chemicals get even more poisonous to frogs after they enter the body and begin to be digested, or after they've been hanging around in the environment for a while and begin to degrade - 10 times more toxic in the case of diazinon, and 100 times more toxic in the cases of chlorpyrifos and malathion.

Frogs may be a "canary in the coal mine" for pesticides because of their moist, permeable skin, but according to one of the lead researchers on this study, Dr. Gary Fellers, these findings do not bode well for other species, including birds, mammals and humans.

OPs are widely implicated in the declines of several amphibian species in the California Central Valley and in downwind mountain areas that are prone to pesticide drift. U.C. Berkeley scientist Tyrone Hayes has also found that the nation's #2 most popular herbicide, atrazine, can cause hermaphrodism and other serious health effects in male frogs, even at very low levels.

These findings implicate pesticide contamination in a widespread decline in amphibian populations across the country, and even worldwide.

People must heed the warning of these green (and increasingly blue!) canaries in the proverbial coal mine, since we depend on the same water that frogs do, and a growing body of scientific evidence indicates that we are also being affected. Consider the recent finding from a researcher at Indiana University School of Medicine that rates of premature birth in humans are highest each year during the same months that pesticide and fertilizer levels spike in surface water, and lowest in the months when pesticide and fertilizer levels are lowest (link). Or, the finding that that children conceived in Indiana during the months of high pesticide use score lower on standardized tests than children conceived in months with low pesticide use (link).

While municipal drinking water treatment systems kill bacteria that could threaten human health, they seldom remove chemical contaminants - including pesticides and their break down products. Filtering your tap water to remove some impurities is a quick fix, but it is urgent that people act now to keep pesticides out of our waterways. For starters, please support farmers that don't use pesticides by buying locally-grown organic foods whenever you can, and sign up for PESTed's Action Alerts to stay in the loop about pesticide issues in North Carolina, and what you can do to make a difference.

Breast cancer triggers

Do chemical contaminants in the environment cause breast cancer? An excellent article in the Los Angeles Times describes the most comprehensive study to date of the evidence linking breast cancer to environmental pollutants (read the whole study here).

The results? More than 200 chemicals, including industrial solvents, pesticides, dyes, cosmetics ingredients and diesel exhaust, cause breast cancer in laboratory studies. Scientists have long known that only a small minority of breast cancer cases are linked to genetic factors, and that environmental triggers must play an important role. Unfortunately, the study of environmental triggers of breast cancer has taken a back-seat to other factors such as diet and exercise. But because breast cancer has become such a common disease, and because our exposure to these carcinogenic contaminants is so widespread, "if even a small percentage is due to preventable environmental factors, modifying these factors would spare thousands of women," according to the study's authors.

Unfortunately, in the US, government regulators typically wait until they have all the evidence of human toxicity to take action, rather than relying on the red flags raised by animal studies. Tufts University cell biologist Anna Soto, interviewed for the LA Times story, disagrees with this approach and urged preventive action.

"When you look at their list of chemicals, we are exposed to all of it," Soto said. "We will never have the whole picture, and it will take many, many years to collect epidemiological evidence, so we should take some preventive measures now."

So what can we do? States and local governments can adopt stricter emissions and drinking water standards to reduce the exposure of the whole population to carcinogenic compounds like diesel exhaust and dry cleaning solvents. As individuals, we can buy safer products and eat cleaner diets of fresh fruits and vegetables, particularly those that are grown organically. Check out PESTed's Go Organic page for resources, and be sure to visit the new Women's Health and the Environment toolkit for lots of great information that you can share with the women in your life.