Archives for category: Periodicals

From Today’s New York Times: “Study: Human Exposure to BPA ‘Grossly Underestimated’” (by Gayathr Vaidyanathan), here is the introduction to an article discussing an important new study (by Julia Taylor, a biologist at the University of Missouri, and her co-authors):

Americans are likely to be exposed at higher levels than previously thought to bisphenol A, a compound that mimics hormones important to human development and is found in more than 90 percent of people in the United States, according to new research.

U.S. EPA says it is OK for humans to take in up to 50 micrograms of BPA per kilogram of body weight each day. The new study, published in the journal Environmental Health Perspectives, suggests that we are exposed to at least eight times that amount every day.

“Our data raise grave concern that regulatory agencies have grossly underestimated current human exposure levels,” states the study.

The study also gives the first experimental support that some BPA is likely cleared at similar rates in mice, monkeys and humans, making it possible to extrapolate health studies in mice to humans.

Despite decades of research, questions about BPA have lingered and recently become politicized. Sen. Dianne Feinstein (D-Calif.) hopes to add an amendment to the “FDA Food Safety Modernization Act,” currently under consideration in the Senate, banning the chemical from children’s food and drink packaging. Republicans and industry representatives have been averse, saying that research has not shown conclusively that the chemical is harmful.

Hormones are essential during development and can determine, among other things, a child’s gender. BPA, since it mimics estrogen, is an “endocrine disrupter,” according to Thomas Zoeller, a biology professor at the University of Massachusetts, Amherst. And amazingly, BPA has the ability to bind to not one, but three receptors — the estrogen, the male hormone and the thyroid hormone receptors, Zoeller said.

You can read the entire Times article here.

* * *

Here are excerpts from the University of Missouri press release:

COLUMBIA, Mo. – Researchers have discovered that women, female monkeys and female mice have major similarities when it comes to how bisphenol A (BPA) is metabolized, and they have renewed their call for governmental regulation when it comes to the estrogen-like chemical found in many everyday products.

A study . . .  ties rodent data on the health effects of BPA to predictions of human health effects from BPA with the use of everyday household products. . . .

“This study provides convincing evidence that BPA is dangerous to our health at current levels of human exposure,” said Frederick vom Saal, Curators’ professor of biological sciences at the University of Missouri. “The new results clearly demonstrate that rodent data on the health effects of BPA are relevant to predictions regarding the health effects of human exposure to BPA. Further evidence of human harm should not be required for regulatory action to reduce human exposure to BPA.”

BPA is one of the world’s highest production-volume chemicals, with more than 8 billion pounds made per year. It can be found in a wide variety of consumer products, including hard plastic items such as baby bottles and food-storage containers, the plastic lining of food and beverage cans, thermal paper used for receipts, and dental sealants. The findings in the current study suggest that human exposure to BPA is much higher than some prior estimates and is likely to be from many still-unknown sources, indicating the need for governmental agencies to require the chemical industry to identify all products that contain BPA.

Several states, including Connecticut, Massachusetts, Washington, New York and Oregon, have passed bills to reduce exposure to BPA, and similar legislation is pending in the U.S. Congress.

“For years, BPA manufacturers have argued that BPA is safe and have denied the validity of more than 200 studies that showed adverse health effects in animals due to exposure to very low doses of BPA,” said Julia Taylor, lead author and associate research professor at the University of Missouri. “We know that BPA leaches out of products that contain it, and that it acts like estrogen in the body.”

“We’ve assumed we’re getting BPA from the ingestion of contaminated food and beverages,” said co-author Pat Hunt, a professor in the Washington State University School of Molecular Biosciences. “This indicates there must be a lot of other ways in which we’re exposed to this chemical and we’re probably exposed to much higher levels than we have assumed.”

* * *

You can read the abstract and download the study here or download a pdf of the study directly here. (Citation: Taylor JA, vom Saal FS, Welshons WV, Drury B, Rottinghaus G, Hunt PA, et al. 2010. Similarity of Bisphenol A Pharmacokinetics in Rhesus Monkeys and Mice: Relevance for Human Exposure. Environ Health Perspect.)

Tomorrow, I will post the portion of my interview with Drs. Carlos Sonnenschein and Ana Soto when I asked them about their pathbreaking work on BPA.

Today’s New York Times features an outstanding summary of current debates — political and scientific — regarding the health effects of the chemical bisphenol-A, or BPA.  The article, titled “In Feast of Data on BPA Plastic, No Final Answer,” was written by Denise Grady who writes a lot about science and medicine.  I’ve pasted a few snippets from the article below; you can read the article in its entirety here.
* * *

The research has been going on for more than 10 years. Studies number in the hundreds. Millions of dollars have been spent. But government health officials still cannot decide whether the chemical bisphenol-A, or BPA, a component of some plastics, is safe. The substance lines most food and drink cans, and is used to make hard, clear plastic bottles, containers and countless other products. Nearly everyone is exposed to it.

Concerns about BPA stem from studies in lab animals and cell cultures showing it can mimic the hormone estrogen. It is considered an “endocrine disruptor,” a term applied to chemicals that can act like hormones. But whether it does any harm in people is unclear.

Where science has left a void, politics and marketing have rushed in. A fierce debate has resulted, with one side dismissing the whole idea of endocrine disruptors as junk science and the other regarding BPA as part of a chemical stew that threatens public health.

About half a dozen states have banned BPA in children’s products, and Senator Dianne Feinstein hopes to accomplish the same nationwide, with an amendment to the food safety bill scheduled for a vote in the Senate next week.

* * *

In May, a White House task force on childhood obesity issued a report suggesting that BPA and certain other chemicals might be acting as “obesogens” in children — promoters of obesity — by increasing fat cells in the body and altering metabolism and feelings of hunger and fullness.

Perhaps not surprisingly, the issue of whether BPA is safe has become highly partisan.

Environmental groups and many Democrats want BPA banned, blaming it for an array of ills that includes cancer, obesity, infertility and behavior problems. Environmentalists think the United States should adopt the “precautionary principle,” a better-safe-than-sorry approach favored in the European Union. The principle says, in essence, that if there are plausible health concerns about a chemical, even if they are not proved, people should not be exposed to it until studies show it is safe. The United States takes the opposite approach: chemicals are not banned unless there is proof of harm.

Many Republicans, anti-regulation activists and the food-packaging and chemical industries insist that BPA is harmless and all but indispensable to keeping canned food safe by sealing the cans and preventing corrosion, and to producing many other products at reasonable prices. . . .

* * *

The idea that drugs or chemicals could act like hormones emerged in the 1990s. Such effects can be subtle and delayed. Hormones act on receptors in cells, structures to which they attach — the standard comparison is lock and key — and orchestrate growth, differentiation and all sorts of biochemical activities. Many cells have receptors for estrogen, and BPA can bind to those receptors, though far less strongly than the body’s own estrogen can.

R. Thomas Zoeller, a biology professor at the University of Massachusetts, Amherst, said BPA could also bind to receptors for male hormone and thyroid hormone.

“I don’t know of a single other molecule that does this,” Dr. Zoeller said.

In people, the most notorious example of an endocrine disruptor is the drug diethylstilbestrol, or DES, which was given to pregnant women in the 1950s in the mistaken belief that it could prevent miscarriage. The drug turned out to be a disaster, causing vaginal cancers and reproductive problems in some of the women’s daughters, and abnormalities in the reproductive organs in some sons. But DES is a far stronger estrogen mimic than is BPA, and women were exposed to much higher levels of it.

Animal studies during the past decade or so began raising concerns about BPA, which is used to harden polycarbonate, a clear plastic that makes nice-looking food containers, bottles and sippy cups. It has been widely used since the 1960s and is also in some medical devices, dental sealants, thermal paper for cash register receipts and the epoxy resin that lines most food and drink cans. The United States produces about a million tons of it a year.

* * *

Last year, a scientific group called the Endocrine Society issued a 34-page report expressing serious concerns about endocrine-disrupting compounds, including BPA, dioxins, PCBs, DDT, the plasticizers known as phthalates and DES.

The society has about 14,000 members from more than 100 countries, who work in medicine, biology, genetics, immunology, industry and other areas.

The report said there was strong evidence that endocrine disruptors could harm the reproductive system, causing malformations, infertility and cancer. It noted that the chemicals could affect all endocrine systems, and said there was mounting evidence for effects on the thyroid gland, brain, obesity and metabolism, and the body’s ability to regulate insulin and glucose levels. It also said that fetuses exposed to chemicals in the womb could experience effects later in life, and pass those abnormalities to future generations.

Scientists call such effects “the fetal basis of adult disease,” and say they probably result from epigenetic changes — meaning that the chemicals alter the functioning of genes, turning them on or off, but do not cause mutations, which are changes in the actual structure of the genes. Some scientists said that they had doubted that low doses could cause harm, but changed their minds after seeing the data.

“I was skeptical that there were effects that were repeatable,” said Gail S. Prins, a professor of physiology at the University of Illinois at Chicago, and an author of the Endocrine Society’s report. But in 2001 she was part of a panel that analyzed dozens of BPA studies for the National Toxicology Program. The panel had its own statistician reanalyze raw data from the studies to find out if the claims based on it were valid.

“I could see there was some consistent data,” Dr. Prins said. “I started thinking, ‘Hmm, maybe there could be something there.’ It was still curious to me. This is not a regular toxicant. It’s acting like a hormone, and hormones can act at extremely low doses. If you think the dose makes the poison, it doesn’t make sense. But if you think about it as a hormone — and I’m an endocrinologist — it does make sense.”

* * *

Over the next few years, researchers hope to bring coherence to this confused and troubled field.

“This is a chemical we’re all exposed to, and I think that makes it incumbent upon us to study it,” Dr. Birnbaum said. “We really need to know what it might be doing, if anything.”

In May of 2008, Newsweek Science writer and author Sharon Begley reviewed the book “Doubt Is Their Product: How Industry’s Assault on Science Threatens Your Health.”

* * *

That science can be bought is hardly news to anyone who knows about tobacco “scientists.” But how pervasive, effective and stealthy this science-for-hire is—as masterfully documented by David Michaels of George Washington University in his new book, “Doubt Is Their Product: How Industry’s Assault on Science Threatens Your Health”—will shock anyone who still believes that “science” and “integrity” are soulmates. In studies of how toxic chemicals affect human health, Michaels told me, “It’s quite easy to take a positive result [showing harmful effects] and turn it falsely negative. This epidemiological alchemy is used widely.”

The alchemy is all in how you design your study and massage the data. Want to show that chemical x does not raise the risk of cancer? Then follow the exposed population for only a few years, since the cancers that most chemicals cause take 20 or 30 years to show up. Since workers are healthier than the general population, they start with a lower death rate; only by comparing rates of something the chemical is specifically suspected of causing—a particular lung disease, perhaps—can you detect a problem. Or, combine data on groups who got a lot of the suspect chemical, such as factory workers, with those who got little or none, perhaps their white-collar bosses. The low disease rates in the latter will dilute the high rates in the former, making it seem that x isn’t that toxic. All these ruses have been used, delaying government action on chemicals including benzene, vinyl chloride, asbestos, chromium, beryllium and a long list of others that cause cancer in humans. “Any competent epidemiologist can employ particular tricks of the trade when certain results are desired,” Michaels writes.

* * *

This is all very big business. “Product-defense firms” have sprung up to spin the science and manufacture doubt—proudly. . . .

Make no mistake: raising doubt has run up the body count. By the early 1980s, for instance, studies had shown that children who took aspirin when they had a viral infection such as chickenpox were at greater risk of developing Reye’s syndrome, which damages the brain and liver and is fatal in about one case in three. Desperate to protect their market, aspirin makers claimed the science was flawed, called for more research (a constant refrain), and ran public-service announcements assuring parents, “We do know that no medication has been proven to cause Reye’s.” The campaign delayed by years the requirement that aspirin carry a warning label about children and Reye’s. In the interim, thousands of kids developed Reye’s. Hundreds died.

* * *


Video of David Michaels authors@Google presentation.

From Scotland’s Herald:

Tens of thousands of tonnes of toxic waste from Scotland are being illegally dumped in Africa and Asia every year with the help of organised criminal gangs, according to an investigation by the Scottish Government’s environmental watchdog.

Mountains of broken televisions, defunct microwaves, worn tyres, contaminated paper and other waste exported from Scottish homes and businesses end up threatening the environment and endangering the health of people in Nigeria, Zanzibar, Ghana, Indonesia, Pakistan, China and elsewhere.

But now the Scottish Environment Protection Agency (Sepa) is cracking down on the criminal trade, and has stopped eight major shipments this year. Four other illegal waste cargoes from Scotland have been intercepted by regulatory agencies in England, The Netherlands and Belgium since 2008.

Read the entire article here.

Los Angeles Times: Obama administration leaves climate change to Congress, not the courts. “Environmentalists say they are surprised and disappointed that the Obama administration is urging the Supreme Court to kill a major global warming lawsuit that seeks new limits on carbon pollution from coal-fired power plants.” Read more here.

Hartford Courant: Tylerville Residents Voice Anger Over Water Woes. “For more than 30 years, drinking wells in the Tylerville section of Haddam, between state Route 154 and the Connecticut River, have been polluted with TCE, a once common solvent now banned from some industries because of its potential health risks. . . . But some residents, at their wits’ end already, bristle at that notion, saying they can’t sell their homes as long as they are living in a contamination zone and feel their long-term physical and emotional health is in jeopardy. In addition, some health officials say the filters are designed to be temporary measures, and are not meant to indefinitely handle TCE levels that have been measured as high as 124 times the allowable limit in a Tylerville residential drinking well. . . . Anger has now begun to boil over at the snail’s pace of the cleanup efforts and what many, including an environmental monitoring council appointed by the governor, see as a soft enforcement posture by state regulators against the former Sibley Co.” Read more here.

Louisiana Daily Comet: Illness from spill unknown still. “When he started working on a crewboat for Guilbeau Marine in May cleaning up the Deepwater Horizon spill site, the 35-year-old Pierre Part native said, he became gravely ill. He can no longer work, medical bills and household expenses ate up a piddling settlement, and promised help from Kenneth Feinberg’s Gulf Coast Claims Facility has yet to materialize. Matherne now begins each day afraid of the future and wondering how much of one he has.” Read more here.

Sarasota Herald-Tribune: Child’s cancer risks rise ‘before pregnancy’: Biggest study on preventing the disease finds parents’ habits and upbringing play major role. “The chances of getting cancer begin even before conception, according to one of the world’s leading experts in nutrition. Women’s lifestyles before getting pregnant and while carrying their baby have a major impact on whether their child will develop the disease, Professor Ricardo Uauy said. Uauy, an adviser to the United Nations and the World Health Organisation, has put together the most comprehensive picture yet of cancer prevention throughout the course of a life, including how what happens to babies helps to define their risk later. Whether a mother-to-be smokes, drinks or is overweight all play a key role, said Uauy, a professor of public health nutrition at the London School of Hygiene and Tropical Medicine. Cancer risk is usually associated with people’s genes and their behaviour as adults. But emerging scientific evidence pinpoints the influence both of parents and the family’s circumstances, he said.” Read more here.

New York Times: Senate bill on food safety is stalled. “After his mother died from eating contaminated peanut butter, Jeff Almer went to Washington to push for legislation that might save others from similar fates. And then he went again. And again. And again. . . .”  Read more here.

Sarasota Herald-Tribune: For chemical disaster, just add storm surge. “More than 20 million tons of some of the most toxic chemicals on the planet are housed in risky storm surge zones on one of the nation’s most hurricane-prone coasts, a looming hazard that could produce an environmental disaster on par with the Gulf oil spill. . . .” Read more here.

%d bloggers like this: