A newly published study is the first to report an association between bisphenol-A (BPA), a common plasticizer used in a variety of consumer food and beverage containers, with autism spectrum disorder (ASD) in children. The study, by researchers at Rowan University School of Osteopathic Medicine (RowanSOM) and Rutgers New Jersey Medical School (NJMS), shows that BPA is not metabolized well in children with ASD.
New ingredient in plastic bottles, receipts has same effect on lab animals as the old chemical does.
Read the story at National Geographic
‘Risk’ and ‘hazard.’
These two words are often used interchangeably, but they have distinct meanings in the context of chemical safety assessment. When we say a particular chemical is ‘hazardous,’ we are noting its mere potential to cause negative health or environmental effects. On the other hand, ‘risk’ describes the probability that these negative effects will actually occur under specific circumstances. In order to generate a measurable risk, some exposure to the hazard in question must occur.
If you have followed my last several posts, you’ve probably caught on to the idea that attempting to declare a chemical ‘safe’ or ‘unsafe’ is an exercise in futility. To comprehensively determine risk, we must know not only the detailed structure and function of a chemical, but also understand the intricacies of its interactions with the environment and the human body. Current chemical regulation in the United States operates within a risk-based framework. We establish standards and criteria for acceptable levels of hazardous compounds in products, in the environment and in our bodies; we enact bans and restrictions on chemicals in order to limit our exposures. These regulations are the product of risk assessments, which report not only the hazardous properties of chemicals but also the likelihood of human exposure.
My recent post on BPA illustrates the complexity of risk assessment. Though BPA has demonstrated hazardous potential, the levels to which humans are exposed to the compound, and therefore the actual risks of its use, are uncertain. Exposure may seem like a simple factor to evaluate, but our understanding of exposure is continually evolving, particularly with consideration for the special vulnerability of developing babies and children. The ban on BPA in baby bottles reflects this emerging awareness of long-term effects of chemical exposures. However, the replacement of BPA with BPS illustrates the shortcomings of an approach that controls risk by limiting exposure to specific high-profile hazardous compounds.
The replacement of BPA, a known hazard, with BPS – an untested and unregulated compound with a nearly identical structure – may be considered an example of what scientists and regulators refer to as “regrettable substitution.” Regrettable substitution occurs when we eliminate one hazardous chemical from consumer products, only to replace it with a similar or even more hazardous alternative. Our risk-based chemical regulation enables us to remove demonstrably dangerous chemicals from consumer products, but also leaves profound loopholes for new chemicals, untested and unregulated, to enter the market in their stead, as long as risk assessments have not proven them dangerous. In a 2010 post on his Environmental Defense Fund blog, Dr. Richard Denison refers to this process as playing “whack-a-mole” with chemicals. No sooner have we knocked one hazardous chemical back into its hole, than a replacement rears its likely-hazardous head…until we generate evidence of its actual risk and seek to replace it with another unknown quantity.
Is this game of “whack-a-chemical” inevitable, or do more precautionary approaches exist? In Europe, regulators are striving for a balance between risk assessment and the more protective approach of hazard classification. While risk assessment relies on scientific studies to determine the risks of chemicals under different exposure scenarios, hazard classification groups chemicals based on their inherent hazard potential. It is this potential to cause harm that guides regulation, not demonstrated adverse effects. A hazard classification regulatory scheme might have prevented BPS from entering the market, since its structural similarities to BPA make it a likely health hazard.
Hazard classification is essentially a more precautionary approach to chemical regulations. And when we operate in a framework of precaution rather than risk, the regulatory question itself changes. “A precautionary approach asks how much harm can be avoided rather than asking how much is acceptable,” write Dr. Ted Schettler and coauthors in a 2002 essay on the role of the Precautionary Principle in regulation and policymaking.
How can we better incorporate the Precautionary Principle into the chemical regulation process in the US? This question has been at the epicenter of the debate on reforming the Toxic Substances Control Act (TSCA), which I will cover next time on Backyard Talk.
Exposure to low levels of common chemical (phthalates) shown to possibly affect reproductive health of male newborns
“…”Our findings show that even at low levels, environmental exposure to these ubiquitous chemicals can adversely affect male genital development, which in turn may impact male reproductive health later in life,” said Dr. Swan, who is also a faculty member of The Mindich Child Health and Development Institute at Mount Sinai. “Because most pregnant women are exposed to phthalates, our findings not only have a profound effect on public health, but on the public policies meant to protect women as well as the general population.”"
‘Name a major public health concern over the past two decades and there’s likely some link to phthalates exposure.’ What are the real risks?
The Guardian covers recent reports on pthalates’ safety.
Two weeks ago on Backyard Talk, I wrote about BPA, a major plastic component that has been linked to number of health impacts, particularly endocrine disruption. The jury is still out on BPA; the European Food Safety Authority has declared that BPA does not pose a health risk at normal exposure levels, while recent studies have emerged showing that BPA affects stem cells and may impact reproductive health later in life. In the face of all this scientific uncertainty, it’s lucky that we have access to BPA-free products. Or is it?
I have a few new water bottles from Christmas sitting in my cabinet, stamped with a leaf design and a guarantee that their plastic is BPA-free. Our eco- and health-conscious readers probably have similar items in their homes. BPA-free products have proliferated since the U.S. Food and Drug Administration banned the sale of baby bottles containing BPA in 2012. Unfortunately, studies over the past few years have shown that even BPA-free products release estrogenic compounds, some of which can even be more potent than those released by BPA-containing products.
One common replacement for BPA, or bisphenol A, is BPS, or bisphenol S, which has been shown to disrupt cell functioning at very tiny concentrations. It’s no surprise that the compounds might have similar effects, because they are close in structure as well as in name. A brief organic chemistry interlude:
To the right is an image of BPA side-by-side with a particular estrogen, estradiol.
This image highlights the structural similarities between BPA and estradiol, which enable BPA to mimic the hormone and cause disruptions to the endocrine system.
Below is the structure of BPS:
Though the two molecules are not identical, BPS contains the essential ring structure, called a ‘phenol’ group, which is highlighted in both BPA and estradiol. Structural similarity between BPA and BPS is what enables them to play a similar role in conferring hardness to plastics. It also enables them to interact with cells in similar ways. According to Scientific American, BPS is thought to be more resistant than BPA to escaping from plastics when they are heated. However, studies have demonstrated that it is prevalent in human urine, and that even small amounts can cause changes to cells.
We are caught between a rock and a hard place when it comes to developing safe, or safer, alternatives to chemicals that have been linked to adverse health or environmental impacts. When replacing chemicals in products, we often first look to chemicals that share properties with the ones we are seeking to eliminate. As in the case of BPA, however, these similarities that preserve the function of a product can also preserve its toxic effects. When health risks are demonstrated for a given compound, is it prudent to bring in a replacement, even if this new player has not been vetted by scientific studies? Should we settle for lesser risk and continue working towards an even safer ideal? What does ‘safe’ mean, anyway? Tune in next time!
Most people know that some plastics additives, such as bisphenol A (BPA), may be harmful to their health. But an upcoming study in the journal Environmental Health finds that entire classes of plastics—including the type commonly referred to as styrofoam and a type used in many baby products—may wreak havoc on your hormones regardless of what additives are in them.
The study’s authors tested 14 different BPA-free plastic resins, the raw materials used to make plastic products, and found that four of them released chemicals that mimic the female hormone estrogen. That’s not surprising. As Mother Jonesreported earlier this year, many BPA-free plastic goods—from baby bottles and sippy cups to food-storage containers—leach potentially harmful estrogenlike chemicals. But until now, it wasn’t clear what role the resins played. The new study suggests that sometimes the resins themselves are part of the problem, though additives such as dyes and antioxidants can make it worse.
It is hard to believe that the FDA recently gave manufacturers the “OK” (again) to use Bisphenol A (BPA). You heard us right. They realize that there are concerns surrounding the endocrine disrupting chemicals and are continuing to research it. But in the meantime, manufacturers still have the “OK” to let it show up in canned items. Our friends at One Green Planet blogged about this disconcerting news here.
Under our weak federal laws, it’s impossible for us to know all the uses of BPA in consumer products. As a result, we don’t even have an exhaustive list of all the products containing these chemicals.
Although, BPA-free products are on the market one of BPA’s substitutes, Bisphenol-s (BPS), is no better. The Washington Post recently released this article, “How to avoid products with toxic bisphenol-s”. Check it out and feel free to share it with your networks.
As we continue to push for reform of our toxic chemical laws, it is times like these when I know our movement must grow.
We are thrilled to announce that today, Coming Clean and the Environmental Justice and Health Alliance (EJHA) launched the Campaign for Healthier Solutions – a national markets and grassroots campaign pushing discount retailers — “dollar stores” — to get toxic products off their store shelves. Our goal is to move these retail companies from laggards to leaders in transition to safer chemicals, and to reduce toxic chemical exposures in communities of color and low-income communities that are already disproportionately impacted.
Today’s launch involved dozens of environmental justice and market groups on the local, state and national levels, and included elements such as:
- A new report, A Day Late and a Dollar Short, with test results from 164 dollar store products in 6 states. We found arsenic, bromine, chlorine, lead, mercury, and phthalates and more.
- A campaign video, with voices and images from communities that are often reliant on dollar stores to provide goods.
- Collaborative media release on the report, which is being picked up by both mainstream (including CNBC) and Spanish-speaking media all over the country. We expect many more media hits throughout the day and week.
- Letters to the CEOs of four major dollar store chains (Family Dollar/Dollar General, Dollar Tree, 99 Cents Only). The letters were signed by representatives from 142 different organizations representing 35 states.
- Action alert enabling people to send messages to the CEOs, and sign on for the campaign!
Thanks so much to the John Merck Fund for supporting the launch of this campaign and to those of you that have provided general support to both Coming Clean and EJHA – we couldn’t have made this happen without you! We’ll be reporting more results soon, and would love to follow up with others interested in helping resource this dynamic campaign.
For those who keep up with environmental health research and chemical regulations, it is no surprise to come across conflicting reports on the safety or risk of various compounds. This week, in the case of the compound bisphenol A (BPA), these conflicting reports happened to emerge almost simultaneously. On January 21st, the European Food Safety Authority declared that BPA “poses no health risk to consumers of any age group…at current exposure levels.” The next day, a study published in the journal PLoS Genetics showed that even low and short-term exposures to BPA and other hormone-mimicking compounds could alter stem cells and lead to lower sperm counts.
BPA is a common ingredient in plastics used for food and drink containers. Its hormone-like properties allow it to disrupt the endocrine system, with potential health effects ranging from reproductive issues to cancer. Though BPA has been banned in baby bottles in the U.S., and BPA-free products have become widely available since concerns about the compound were first raised in 2008, it remains in products from water bottles to the inside coatings of cans.
‘The dose makes the poison’ is a well-known adage in toxicology, implying that even hazardous chemicals can be harmless at low enough concentrations. However, decades of research have shown this to be an overly simplistic way of analyzing toxic exposures. Dr. Theo Colborn, who passed away on December 14th, 2014, was a pioneering researcher in the field of endocrine disruption and a tireless advocate for precautionary chemical regulation. Her research on endocrine disruption demonstrated that even very low concentrations of harmful chemicals could result in changes to the reproductive system, particularly in developing babies and children who have less of a tolerance for exposure than adults. She also demonstrated that not all effects of toxic chemicals are immediately apparent, but can occur decades and even generations later.
The study published last week focused on both questions of concentration and timing. The researchers tested estrogenic compounds including BPA on mice, and found that they alter the stem cells, or undifferentiated cells, which are responsible for sperm production later in life. Patricia Hunt, the researcher who led the study, told Environmental Health News that exposure to even low doses of estrogens “is not simply affecting sperm being produced now, but impacting the stem cell population, and that will affect sperm produced throughout the lifetime.”
Uncertainties remain in the wake of this study. For instance, the researchers are still investigating whether the changes observed can cross generations, or whether the same changes can occur in human reproductive stem cells. The EFSA also recognized uncertainties in non-dietary sources of BPA, and they are still conducting long-term studies in rats. While scientists and regulators continue to chase answers, this past week shines a spotlight on the complicated realm of environmental health risk assessment, and shows the continued relevance of Dr. Theo Colborn’s work and legacy. Dose is indeed important in making a poison, but so is timing of exposure, and time itself in revealing the chronic and transgenerational effects of chemicals.