September 28, 2006
National Geographic Looks at Toxics
The October 2006 issue of National Geographic deals with a personal view of chemical exposure in everyday life. In an article titled The Pollution Within, the author, David Ewing Duncan, chronicles the comprehensive survey of his daily interaction with (mostly) man-made chemicals in a wide range of venues, including air travel. He was tested for 320 chemicals that he might have picked up from food, drink and air, as well as products that touch the skin. The results give one pause for thought, and complicate the perception that while health statistics have been improving for decades, the rates of occurrence of some illnesses have been rising significantly.
In the article, particular mention is made of the fact that until recently, no one had even measured average levels of exposure among large numbers of Americans because no regulations required it and the technology needed to measure the "tiniest" levels didn't exist.
The article did acknowledge that the realm in which many of these analytes were being detected was extraordinarily low. One toxicologist was quoted as saying: "In toxicology, dose is everything, and these doses are too low to be dangerous." One part per billion, considered the standard unit for measuring most chemicals inside the body, is like putting half a teaspoon of red dye into an Olympic-size swimming pool. In addition, some of the most feared substances, such as mercury, dissipate within days or weeks if the body weren't constantly re-exposed.
Many chemical species were not included in the test regimen for various reasons including practicality. For inquiring minds who have been tuned into the mission of the VanishingZero site, these omissions included various solvents, plastics, and "a rocket-fuel ingredient called perchlorate," exposure to which has been defined by informed toxicologists as safe for the U.S. population to levels of at least 200 ppb.
September 28, 2006 in Media Responsibility | Permalink | Comments (0) | TrackBack
July 07, 2006
News Bits
The wire services occasionally offer some interesting chemical information to ponder, to wit:
1) Benzene - The FDA is speculating that changes in analytical methods may be the cause for recent results showing low levels of benzene in some drinks. In the past, the FDA protocol allowed heating of samples to 100 deg C for thirty minutes, conditions which may favor decarboxylation of benzoic acid to form traces of benzene. Products having ascorbic acid and sodium benzoate as ingredients may have been affected.
2) Perchlorate - There has been a report that the presence of traces of perchlorate has been confirmed in some vitamins. While the source is uncertain, one possibility is seaweed - which has long been known to be rich in iodide, possibly collected by a mechanism that is capable of concentrating naturally occurring perchlorate as well.
July 7, 2006 in Media Responsibility | Permalink | Comments (0) | TrackBack
January 30, 2006
FDA rejects charges against duPont product
Two letters of interest to "fairness in media" advocates have been posted at the following site:
http://www2.dupont.com/PFOA/en_US/pdf/MedAdv_FDADismissesEWGAllegations.pdf.
The first is a Media Advisory issued by duPont to present the fact that over two dozen media outlets had previously reported false allegations made by the Environmental Working Group regarding the safety of grease-resistant paper products made with duPont materials.
The second is the letter from the FDA to EWG that in specific detail rejects the EWG claims against the fluoroadditive resin Zonyl RP. It was also noted in the Media Advisory that the Consumer Products Safety Commission previously rejected a request by EWG to require a warning label on cookware coated with Teflon(R), stating that EWG had failed to provide any evidence that consumer use would cause human illness or injury.
DuPont also stated that because of the "false accusations made during a news conference" on November 16, 2005, more than 30 million consumers may have been misinformed about the safety of Zonyl.
January 30, 2006 in Media Responsibility | Permalink | Comments (3) | TrackBack
January 06, 2006
WSJ Weighs in on Perchlorate Issue
The December 29, 2005 issue of the Wall Street Journal featured the last of a series of front page articles on the theme of Toxic Traces: New Questions About Old Chemicals, and specifically revisited the issue of what level of perchlorate exposure poses risk to human health. Central to this issue is "the burgeoning science of low-dose chemical exposure" and the uncertainty that governs what is known about perchlorate effects in the parts per billion realm -- essentially leading to a standoff between elements of the DOD and the EPA. The critical overview reflects the interests and concerns of various parties, including those who feel that public and private dollars would be better spent on more clear-cut health issues that are not burdened by "what-if" scenarios driven by "precautionary principle" reasoning. Taken to its limit, the precautionary principle would dictate that if the evidence about a product or technology is in any way incomplete, it should be prohibited or at least stringently regulated. Unfortunately, the WSJ article did not represent or sufficiently develop several arguments that mitigate against the severe and costly regulation of perchlorate (www.wsj.com)
The factors listed below play into the decision by the National Research Council in 2005 to recommend a maximum safe exposure level equivalent to about 24 ppb perchlorate. Toxicologists are on record as supporting a limit of 200 ppb. Elements within the EPA want a one ppb limit. The state of Massachusetts recently declined to establish, at this time, a perchlorate-specific water quality standard that would have demanded compliance to a one ppb limit, several times more stringent than that adopted by the California EPA. Pertinent factors within the debate include (but are not limited to) the following:
- Perchlorate has been accepted for 50 years for the treatment of thyroid conditions, usually involving exposures 1000 times commonly found environmental levels.
- Occupational studies have found no anomalies in workers exposed to perchlorate at levels well above environmental exposure.
- Extrapolation of rat studies to the human condition is a problematic exercise at best.
- The rat data represent a precursor effect far removed from an actual adverse effect.
- Perchlorate is eliminated from the human body in a very efficient manner.
- The effects of nitrate ion on thyroid function, while less acute than perchlorate effects, can be represented as a greater problem because of the prevalance of nitrate exposure in humans.
Because of various uncertainty factors, it is very difficult to separate the science from the politics of the perchlorate debate. One wonders how that debate would develop if perchlorate were essential to the manufacture of chocolate rather than munitions and propellants.
January 6, 2006 in Environmental Guidelines, Media Responsibility | Permalink | Comments (0) | TrackBack
November 02, 2005
Crichton: Science or Politics ?
While not the purpose of this site to promote popular media, a new book by Michael Crichton - States of Fear: Science or Politics - promises to address topics of particular interest to viewers of this site. The announcement of a November 15, 2005 Crichton presentation and ensuing panel discussion asks: "Is environmental debate today, including global warming, bio-technology, and other issues, based on science or politics? Are popular accounts of such issues rooted in science or phantom risks? Are government policies focusing on the trivial while ignoring the real, and in the process wasting limited resources, crippling human innovation to address true dangers, and inviting tyranny?" The suggestion is made that Crichton's book is a landmark, cautionary and prophetic. One also needs to be reminded that within prevailing US regulatory structure, many issues of environmental import can be addressed at the sole discretion of the EPA Administrator based on his/her perception of "meaningful opportunity for health risk reduction."
November 2, 2005 in Media Responsibility, Political Accountability | Permalink | Comments (0) | TrackBack