A Resolution of Sorts on Bisphenol-A (BPA)

"All paid jobs absorb and degrade the mind." -- Aristotle, with thanks to the Biomes Blog, which is probably a lame excuse for why I struggle with how to blog about important but difficult-to-make-interesting-or-compelling topics such as bisphenol-A in polycarbonate plastics. There’s been plenty of handwringing about cancer, developmental health effects, obesity, etc, from BPA exposure, since the National Toxicology Program (NTP) issued its draft Brief last month (read it here if you dare). Some of the best handwringing is in these articles in Discover, including this nicely-done interview with Philip Landrigan (never heard of him? Shame on you.), who refers to environmental chemicals in general as a vast, uncontrolled human exposure study.

The NTP’s Brief on BPA says nothing new about this substance, really, but the document does that with great authority. The NTP stated, “yes”, people are being exposed to BPA. The NTP stated that BPA can possibly affect human reproduction. Effects on reproduction and development have been observed in laboratory animals at low doses that are within the range of human exposures. These include effects related to neural and behavior alterations, precancerous lesions in the prostate and mammary glands, altered prostate gland and urinary tract development, and early onset of puberty in females. The NTP says there is scientific controversy regarding the interpretation of these low dose effects, but follows with the statement, “[w] hen considered together, the results of “low” dose studies of bisphenol-A provide limited evidence for adverse effects on development in laboratory animals.”

There are a myriad of reasons for why these studies doesn’t give direct answers about bisphenol-A risks, and the NTP’s brief goes on at length, and the even longer and more complex expert report at greater length, about: whether or not adverse effects are reproducible, which is influenced by factors such as the strain of animals studied, animal care and feeding, experience of the investigator in low-dose endocrine methods and the source of funding for the study; are the results biologically plausible, a question that is embroiled in a controversy about the applicability of a dose-response relationship (the gold standard in toxicology as to whether or not exposure to a chemical causes adverse effects) to endocrine disruptors; are the observed effects really adverse effects, etc. Once again, we’ve studied the daylights out of a chemical (as with dioxin, perchlorate and TCE), and still don’t seem to have a definite answer about whether or not it poses significant health risks.

You would think that the risk management thing we need to do here seems reasonably clear. Low levels of this stuff is in the bloodstreams of nearly everyone. There are hints of evidence that similar levels tested in laboratory animals produce adverse effects, though as with all laboratory animal evidence, we don’t really know what that means for humans. The kinds of adverse effects that might be associated with exposure to BPA could extend into the next generation – if it does cause developmental behavioral effects, you might speculate about the implications of a generation of adults with behavioral and learning disabilities. We might be on our way there now, which is why initiatives such as the National Children’s Study are of critical importance.

However, as stated before, the uncertainties in the assessment of BPA don’t point directly to a decision. The easy answers (be precautionary and ban all uses; don’t be hasty, the evidence doesn’t indicate a problem) aren’t the optimal ones. At the end of the day, the most extensive risk assessment in the world isn’t going help inform a decision if the affected public isn’t going to think clearly about its values and choices; and it’s clear that we’re not good at making risk-informed decisions where uncertainty is present.

The lesson from all of this is that the debate over BPA health effects is one about values and politics, not science. It’s probably true that the precautionary principle is incoherent as a decision making tool. At the same time, inaction is a decision, and in the case of restricting BPA from food and beverage containers, one that might have long-term consequences that are severely adverse and virtually irreversible.

We seem to be groping towards a resolution, no thanks to our moribund Congress and regulatory agencies. There’s a little bit of market transparency for parents regarding BPA in plastic food and drink containers for newborns and small children. Nalgene, a major manufacturer of plastic containers is phasing out use of BPA. Though it’s expected to take several months to complete the phase out, Nalgene is, ha ha, claiming it’s products are BPA free now. I suppose it’s a victory of sorts, but I’m not going to get too excited until I see evidence that body burdens are decreasing.

Vegetables and Sex

No, that’s not what I’m talking about, you kinky people. . . .

It’s one of those indisputable bits of knowledge that you need to eat enough fruits and vegetables to stay healthy. There are perhaps two basic ways you could go about promoting more fruit and vegetable consumption:

Harass people with boring, gloomy statistics such as:

- Up to 2.7 million lives could be saved annually with sufficient fruit and vegetable consumption.
- Low fruit and vegetable intake is among the top 10 selected risk factors for global mortality.
- Worldwide, low intake of fruits and vegetables is estimated to cause about 19% of gastrointestinal cancer, about 31% of ischaemic heart disease and 11% of stroke.

OR



Now, that’s what I call social marketing.

(Image courtesy of Copenhagen Wholesale Markets)

The Other Story About the Airline Debacle

Last year, I was on the road about 30% of the time. I grew to loathe airline travel, the cramped accommodations on planes, security theater, boredom, hurry up and wait, the nutritional dead zones called airports, the physical effects from disrupted sleep, eating and exercise habits, and that was before airlines started grounding their fleets to check the planes and make sure they aren't going to fall out of the sky. My sympathies are with the travelers inconvenienced by American Airlines. I may be one with you soon - I'm scheduled to fly towards the end of this month. However, one bright spot is that the present disruptions - grounded fleets and bankrupt airlines - might crystalize in peoples' minds just how broken air travel really is. Maybe they'll even start to think about how unsustainable air travel really is.

There's no way to sugar coat that last one. The Royal Commission on Environmental Pollution published an analysis of the impacts of air travel back in the dim past of 2002. That report raises concerns about air travel providing a disproportionate contribution to global climate change compared with other human activities and modes of transportation, in particular rail and marine. Global climate change is increasingly being viewed as a national security issue (here's the latest rumination from that corner), suggesting that matters such as air travel cannot solely be left up to CEOs; of course as events have shown in Iraq, it also may not be a good idea to leave such matters up to the national security technocrats, either.

With a new call for reducing carbon dioxide concentrations in the atmosphere to 350 ppm (James Hansen's paper on the topic can be found here), it might be time to begin viewing air travel as something that becomes rare in our future. There are alternatives that can offset flying less, such as videoconferencing and high speed rail, but pressure needs to be applied, particularly to get high speed rail going in the US. Of course, this means airline executives will have to find something else to do, and probably see a decrease in their bloated standard of living in the process. Don't expect them to go down quietly, though.

Seven Ideas Lost on Americans

Americans aren’t stupid. I have come to the conclusion that we are either in a state of perpetual denial or in a fog of permanent confusion. Whatever the case, we are overlooking some pretty important ideas that contribute to the current environmental crisis.

Jerald Schnoor, the editor of Environmental Science and Technology and the author of those words is going pretty easy on us. A reasonable person probably couldn’t rule out the possibility that we Americans are stupid. However, he makes up for it in his list of seven ideas lost on Americans. I’ll summarize here, with my own perspective, but the article should be read on its own merits (go ahead, it’s not behind the firewall).

1. Our unsustainability is immense. It’s true. You have to be seriously deluded to believe otherwise. Unless you living at a subsistence level, you’re not really helping (spare me about how green you really are). We really don’t have a clue, and many of the solutions we’re working on, such as biofuels or hybrid cars, provide only little benefit, or actually make matters worse.

2. Tipping points are irreversible. His closing point is educational – people don’t really believe a severe storm or a fire is going to destroy their home, yet they invest in insurance against that possibility. Why can’t we do the same with climate change?

3. Time lag bites. Another thing we don’t get is that the atmosphere doesn’t turn on a dime, even if we summon the will to reduce greenhouse gases. The effects, even if we begin in earnest today, won’t be apparent for over a century.

4. Species matter. This doesn’t involve getting misty-eyed about endangered species. I think that people tend to forget that beyond being beautiful and wondrous, Nature is also FUNCTIONAL.

5. Free markets aren’t free. This should be tattooed mirror-wise on the foreheads of every idiot libertarian, neoconservative economist, nitwit pundit. . . and maybe all Republicans, for that matter. Ecosystem services cost something, even if you don’t want to acknowledge they exist.

6. Inaction can be more expensive than action. There’s money to be made in energy retrofits, carbon sequestration, building mass transit, restoring habitat, rehabilitating soils, etc. etc. Global warming deniers and uncertainty manufacturers are agents of chaos and disinformation in the service of those economic interests who will are fighting a rearguard action to avoid being the big losers in the climate change economy. The fact that a large fraction of us are listening makes us idiots by default.

7. Technology can’t do it alone. We’re going to need a new worldview for how we regard nature in addition to the mother of all Manhattan Projects. I wonder if we’ve got it in us – the current worldview in the US advocates human domination of nature.

Note to self: next time, write the post before cracking open the wine. You’ll sound less cranky that way.

A Resolution of Sorts on TCE

TCE is a prime example among many of the difficulties we face trying to assess and manage the risks from low levels of chemicals in the environment. EPA has been undergoing a torturous risk assessment process since 2001 in order to set regulatory limits. The original TCE risk assessment received abundant criticisms from stakeholders, principally DOD and industries undergoing cleanup of TCE-contaminated sites. Some of those comments could be considered exercises in “manufactured uncertainty”; however, others were on the mark in identifying flaws in EPA’s analysis. Eventually the TCE risk assessment ended up with the National Academy of Sciences, which in 2006 issued a report that partially vindicated EPA, and partially confirmed what EPA’s critics were saying, but in the end, recommended that EPA revise its risk assessment, and quickly. Last year, Congress started getting into the act, sponsoring legislation to set a timeline for EPA to complete its scientific review and propose numbers that could be used for setting cleanup and drinking water standards. This only heightens the unreality of the situation; one would think with war, global climate change, economic meltdown and a crisis in healthcare, Congress would have better things to do with its time than debate the cleanup standards of ONE Superfund contaminant, no matter how prominent it is.

Earlier this month, there was a bit of a resolution on this issue, as reported in the March 18, 2008 Risk Policy Report, published by Inside EPA. At the meeting of federal facilities managers sponsored by the Association of State and Territorial Solid Waste Management Officials (ASTSWMO), EPA announced they it had reached an agreement in principle with the Department of Defense (DOD) on cleanup levels to address inhalation exposures to TCE associated with vapor intrusion. According to the Risk Policy Report:

The move will provide DOD and industry a long-sought consistent national approach to the issue, a DOD source says, as well as allow regulators across the country to make long-delayed cleanup decisions to address vapor intrusion, a previously unrelated pathway that results from toxic vapors from underground solvents that enter homes, offices and other structures

EPA has developed provisional guidance that will adopt the risk assessment prepared by the California Environmental Protection Agency for purposes of setting cleanup standards for vapor intrusion pathways. This will provide some badly-needed consistency in cleanup policy, which will allow remedial actions to move forward (I’ve personally observed sites where action has been stalled over differences in opinion about appropriate risk-based standards for TCE). Currently, state and federal agencies are using a variety of risk assessments which provide up to a 65-fold range in cleanup levels, for the same target cancer risk. EPA states that cleanups should achieve indoor air concentrations ranging from 1 to 10 ug/m3; the ability to protect public health with these levels in air is a matter for further discussion (I’m working on a longer post discussing that issue), but it’s possible that 1 to 10 ug/m3 in air represents levels that can be reasonably achieved with Superfund remedial technologies.

I’ll be back with more on this topic.

A Placeholder for Interesting Things – Trash Pickers and Sustainability

Keeping my pledge to write more frequently means there will be posts like this one which are placeholders until I have the time to explore a topic in more detail. I ran across this fascinating article about trash pickers, the poor around the world who scrape out a living salvaging recyclables from the street and landfills. Someone has written a book about them, which I will pick up and review. After reading this paper a few years ago, which observed that a significant fraction of the global stock of copper resides in landfills, maybe the idea is possible that the despised (or ignored) trash pickers could become a global economic force.

The CDC Great Lakes Report: A Lesson in Transparency

Influential people ranging from Nixon to Clinton (Bill, that is) to untold numbers of Republicans in the Bush administration habitually have been too puffed up with their own importance and perceived invulnerability to comprehend that the cover-up is always worse than the crime. A recent case has been the report regarding potential human exposures to hazardous waste sites around the Great Lakes, which has been in draft by staff of the Centers for Disease Control (CDC), Agency for Toxic Substances and Disease Registry (ATSDR) for the past several years.

The International Joint Commission (IJC) commissioned the report in 2001, according to a report published in the Detroit News and, as of 2004, was undergoing peer review. It was supposed to have been released in July 2008, but the CDC has held up publication. The author of the report, Chris DeRosa, senior toxicologist for ATSDR subsequently was demoted for reasons not specified by CDC.

The Center for Public Integrity has done a good job in bringing this matter to light, and particularly in disclosing portions of the report in question. Most of the liberal blogs and the mainstream media took this information to the wrong place, highlighting the supposed public health threat from contaminated sites around the Great Lakes, which suggests that most of them didn’t read the excerpts of the report all that carefully, if they read them at all. Others such as Revere, did identify a key issue associated with this news, which is another example of the Republican war on science, with Bush administration officials suppressing scientists who have identified environmental health problems that pose a threat to entrenched economic interests.

The House Energy and Commerce committee has gotten into the act, calling CDC into account with regard to this matter. So now the CDC, blithely not mentioning any of this back story, has issued the report in draft along with a statement “scientific concerns” which says that the report is not ready for release to the public. Senior management reviewed the report in 2007 and identified what was felt to be several deficiencies, which they were concerned would lead to misinterpretation of the report by the public. However, due to the inept handling of the review process, it’s a bit late to prevent misinterpretation. A revised draft is being prepared for a review by the Institute of Medicine, which presumably will occur sometime this year.

I must be missing something here. I’m curious about what was so troublesome about the report from a political perspective that it warranted being bottled up for the better part of three years, and demoting a senior toxicologist. According to the latest Detroit News article, the report cost $92,000. It’s hard for me to do more than speculate, not knowing anything about the schedule or the original scope (you can’t find a workplan or protocol or anything similar on IJC’s or ATSDR’s web sites), but for a report assessing potential adverse impacts associated with Superfund sites across multiple states in the Great Lakes region, $92K seems to be a fairly small budget. Awhile back, I took a peek at the draft version circulated on Public Integrity’s web site. It looks like what the authors did was to identify hazardous waste sites and other releases to air and water from publicly available databases, and lined these up with county-level disease burden statistics. This study scarcely produced smoking guns, and is most useful for identifying priorities for more definitive health assessments. And the authors of the study pretty much say these things in the report.

It’s good that CDC has now posted the draft study, along with the comments provided by various reviewers, though it’s a shame that the agency apparently had to be slapped around a bit by Congress before coughing it up. And, if they had simply posted the report without any fanfare, perhaps on a late Friday afternoon which a standard ploy for agencies who have to report unpleasant news, it might have been months before anyone in the press had found it (so when’s the last time you’ve visited ATSDR’s Great Lakes web page). Not in the spirit of transparency, but it would have represented much smarter bureaucratic maneuvering.

Beyond the tempest in a teapot story about suppressing a relatively routine health assessment report useful for identifying future research priorities, and folks who characterize it as anything more really need to get over themselves, there are much more important stories to explore. Revere points to one of them, which is the pattern of harassing scientists who are simply doing their jobs which is identifying public health problems for use in informing policy. Another story is the progressively growing limitations in EPA’s command and control tools (TRI, NPDES, Superfund) for understanding and managing big regional environmental health problems, such as the Great Lakes. Then, there’s the question about why this story didn’t stimulate broader interest in other environmental health research on the Great Lakes, which points to much better documented problems.