PFOA Precursors to be phased out

Leftovers may explain perfluorinated compound puzzle:

See my earlier post about this. Looks like the EPA did want the companies to phaseout not just the PFOA, but the precursor compouds as well, and according to this article, quite a bit of progress has been made.

Eight companies have pledged to slash releases of several perfluorochemicals at their operations around the world, EPA announced on March 2.

Arkema, Asahi, Ciba, Clariant, Daikin, DuPont, 3M/Dyneon, and Solvay Solexis have agreed to reduce emissions of perfluorooctanoic acid (PFOA), its longer chain homologs, and compounds that can degrade into PFOA, EPA said. The companies will also reduce levels of these compounds in their products. Responding to a challenge EPA made in January, the eight firms volunteered to cut industrial releases of PFOA as well as amounts of the chemical in products 95% from 2000 levels by 2010 or earlier. The companies also pledged to work on eliminating releases and content of PFOA in products by 2015.

Here are the individual companies’ commitment letters. They all loudly proclaim their commitment to reduce PFOA levels in their products, not quite so universally unequivocal on the precursors… I need a lawyer to parse some of the language. 3M, for instance, says that they do not “manufacture” the telomers’, which is not the same as saying they do not use them. Solvay Solexis, is extremely straigtforward and agrees to the EPA conditions in a letter actually written in plain English! Dupont, good letter too. Let’s see how this situation plays out, outright elimination in 10 years seems nice, which leads me to believe that the companies are already moving in this direction. The journal article suggests that the residuals are mainly due to inefficiencies in the manufacturing process. The reaction yield is 70%, meaning the 30% left behind from the monomer formation reaction will need to be removed from the product.

Drugs in the water: Behold the power of synergy

funky MathES&T Online News: Can drugs found in water harm humans?

Researchers agree that aquatic species face the greatest risk from exposure to low levels of pharmaceuticals, such as synthetic hormones, which can act as endocrine disrupters at environmental levels. However, little is known about the potential human health effects arising from complex drug mixtures.

Well, it is often more difficult to analyze complex mixtures because Experimental Design 101 makes you want to isolate the effects. And when you do compounds one by one in series, the tendency is to always add them up from the individual experiments. Unfortunately, body chemistry is not like that. I’ve always wanted to design a study that started complex and then tried to isolate later.

To his surprise, Pomati observed that this mixture of drugs at environmental levels inhibited the growth of human embryonic kidney cells. After 48 hours of exposure, cell proliferation was reduced by 10–30% compared with controls. However, no inhibition was observed when cells were exposed to only the toxic cancer drug at environmental levels.

Well, that seems conclusive enough, but here comes the “Experimental Design 101” Scold:

The results show that the growth inhibition is not due to the single most cytotoxic compound alone. But that does not conclusively prove that synergistic or additive effects exist between drugs in the mixture, cautions Thomas Heberer of the Institute of Food Chemistry at the Technical University of Berlin. To show that the individual drugs behave additively, Heberer suggests that researchers should analyze the effects of compounds with a common mode of action, such as antibiotics, alone and in various mixtures.

No, No, and No. Doing this presupposes that you know that mechanism of action, meaning you’ve half answered your question. The question Heberer is trying to answer is “do individual drugs with the same mode of action behave additively”. The question Pomati is trying to answer is “Can we demonstrate cytotoxic effects of a cocktail of drugs at ambient levels in a laboratory setting”? These are two completely different questions and Pomati’s question is more valuable at this point in time. Heberer’s strategy, on the other hand, will keep a lab well funded for years to come! But, it is very much the final step.

It is more important at this point in time to demonstrate other effects such as endocrine disruption, mutagenicity, etc in the lab at environmentally relevant levels of mixtures. Then we can get a better handle on which  effects are relevant and which ones to ignore.

Deep Sixing California’s Prop 65

House mulls bill on food label removal –

“This bill would strip state governments of the ability to protect their residents through state laws and regulations relating to the safety of food and food packaging,” the attorneys general wrote.

The obvious target, they said, is California’s Proposition 65, a law passed by voters requiring companies to warn the public of potentially dangerous toxins in food. The law has prompted California to file lawsuits seeking an array of warnings, including the mercury content in canned tuna and the presence of lead in Mexican candy.

Prop 65 is a California Law that requires the state of California to “publish, at least annually, a list of chemicals known to the state to cause cancer or reproductive toxicity” and for businesses to post warning labels. Well naturally, it kinda depresses sales of canned tuna if you have mercury warnings on the labels, mmm, lead in my candy, so delicious…

This is obviously not good for the consumer, I undestand that businesses feel the burden of extra labeling, depressed sales, etc, but why should the onus always be on the consumer? If the assumption that it is the consumer’s responsibility to find out that there is mercury in his/her tuna and that the informed consumer will make informed choices, why not make it easier on the consumer to find out and then rely on him/her to make that choice? What are the companies afraid of, exactly?

Update 4:24 PM 3-3-2006

More herehere and here

Rising Temperatures Affect Indian Crop Yields

feb-temp.jpgThis story in the Indian Express talks about unusually warm February weather affecting wheat yields in Punjab and Haryana (India’s breadbasket, BTW). This will become more and more common as average temperatures rise from Global Warming. From Lester Brown’s most informative book Plan B 2.0:

Two scientists in India, K.S. Kavi Kumar and Jyoti Parikh, assessed the effect of higher temperatures on wheat and rice yields. Basing their model on data from 10 sites, they concluded that in north India a 1-degree Celsius rise in mean temperature did not meaningfully reduce wheat yields, but a 2-degree rise lowered yields at almost all the sites. When they looked at temperature change alone, a 2-degree Celsius rise led to a decline in irrigated wheat yields ranging from 37 percent to 58 percent. When they combined the negative effects of higher temperature with the positive effects of CO2 fertilization, the decline in yields among the various sites ranged from 8 percent to 38 percent. For a country projected to add 500 million people by mid-century, this is a troubling prospect

We might as well accept that this is going to happen and plan
accordingly. I guess changing the variety would help, so would shifting the growing season a little (I am no crop scientist, so I need to read about this).

Good Bye, Clean Water (Act)

Judith Lewis of the LA Weekly summarizes the issues before the Supreme Court currently debating the Clean Water Act. Among the things she says:

One state’s boon is another state’s disaster, and it doesn’t much matter whether that state is red or blue: If you’ve seen what happens when your swamps disappear, as they have in Florida, you know why it’s important to protect them.

In other words, each state is free to screw up its water and then realize too late that they need to protect their wetlands? This points to the insanity that underlies all Federal Environmental Regulation, they are based on the Federal Government’s authority to “Regulate Interstate Commerce” under the Commerce clause of the Constitution. Since Environmental Protection is not mentioned in the Constitution (did they even have indoor plumbing of the non chamber pot variety?), it is considered a state subject unless it affects “commerce”. This can be interpreted either expansively to protect the environment, or Scalialisciously (thank you, the very wonderful Dahlia Lithwick, the only Supreme Court columnist to have her own fan page) to let any one build/dump wherever they please as long as they are not on the banks of the Mississippi! The CWA specifically empowers states to issue permits and it would seem that an successful challenge would really muddy the waters  🙁

Reading Lithwick’s dispatch leaves me to believe that it’s going to be a close call. Justices Scalia and Roberts seem to be finely parsing language and displaying a contemptuous and obviously fake ignorance of watershed hydrology. Hopefully, the center (Kennedy) will hold, He is a “States Rights” kinda guy, though, which is scary. On the other hand, he likes European Law and Europe is the Queen of classic command and control environmental regulation. Help, I can’t stand the suspense, what do the Vegas lines say???! Here are some of the possible consequences of an unfavorable ruling –

Under that topsy-turvy interpretation of the landmark 1972 law, more than half of all streams in the United States, as well as one-fifth of all wetlands, would no longer be protected, according to the federal Environmental Protection Agency. And waterways that provide drinking water for more than one in three Americans would be at risk. Nearly 150,000 miles of protected streams in California could be threatened.

The federal government is arguing for the continuation of the CWA, which I guess is some relief, hope they want to win this one.

Best Primer to Climate Change ever

The Beeb does it again. Best use of simple graphics to clearly explain science.

Gulf Stream

  1. Surface currents carry warm, salty water from the tropics.
  2. The water cools, its density increases and it sinks to the deep ocean.
  3. The cold water flows back to the equator, driving the “ocean conveyor” which in turn contributes to the Gulf Stream that warms northern Europe.
  4. As ice melts, freshwater dilutes the warm salty water from the tropics.
  5. The water becomes less dense so does not sink as fast, weakening the “conveyor” and therefore possibly disrupting the Gulf Stream.

Gulf Stream

Dramatic temperature shifts have happened in the past, driven partly by changes in a major ocean currents.

A “great ocean conveyor” helps transport heat around the globe via surface and deep-sea movements of water.

Scientists are exploring whether global warming might slow or shut it down – a scenario considered “low probability, high impact”.

This could disrupt mostly wind-driven surface currents such as the Gulf Stream, which brings milder weather to Northern Europe.

Low Probability, High impact indeed, aka the “Hell Freezes Over” Scenario. The Gulf Stream example is one of my favorites, check all the other animation out, it is great.

EPA Calls for End to Releases of Chemical in Teflon Process

Check out this story from the January 26, 2006 LA Times.

In a rare move to phase out a widely used industrial compound, the Environmental Protection Agency announced Wednesday that it was asking all U.S. companies to virtually eliminate public exposure to a toxic chemical used to make Teflon cookware and thousands of other products.

EPA’s system of regulating chemicals leads to some really perverse incentives. The burden of proof shifts to the EPA to prove beyond reasonable doubt that a chemical has definite harmful effects on humans at ambient exposure levels. So the preferred route has been for the EPA to “suggest” to the companies to participate in a voluntary phaseout.

No one knows how the chemical is getting into people’s bloodstreams and in the bodies of polar bears and other animals. Although it is used in production of cookware, it is not found in the cookware, clothing and other fluoropolymers after manufacture.

Well, not quite. This from a paper published in the Environmental Science and Technology on January the 25th.

Polyfluorinated telomer alcohols and sulfonamides are classes of compounds recently identified as precursor molecules to the perfluorinated acids detected in the environment. Despite the detection and quantification of these volatile compounds in the atmosphere, their sources remain unknown. Both classes of compounds are used in the synthesis of various fluorosurfactants and incorporated in polymeric materials used extensively in the carpet, textile, and paper industries. This study has identified the presence of residual unbound fluoro telomer alcohols (FTOHs) in varying chain lengths (C6-C14) in several commercially available and industrially applied polymeric and surfactant materials…

This study suggests that elimination or reduction of these residual alcohols from all marketed fluorinated polymers and fluorosurfactants is key in reducing the prevalence of perfluorinated acids formed in the environment.

Well, that explains it a little better, this article from ES&T provides a nice executive summary like context.

An emerging theory that explains how PFOA (perfluorooctanoic acid) and other PFCAs (perfluorocarboxylic acids) have contaminated the Arctic has received a boost from a new modeling study published in this issue of ES&T (pp 924–930). The theory contends that Arctic contamination is due to atmospheric transport and breakdown of fluorotelomer alcohols, chemicals that are used in products that include stain protectors, microwave-popcorn bags, fast-food wrappers, polishes, and paints.

Well, it sure looks like we need to focus much more on the PFOA precursors rather than on the PFOA itself. Dupont and 3M are not going to be happy about that!