Organic Pollutants Poison the Roof of the World 114
ananyo writes "Toxic chemicals are accumulating in the ecosystems of the Himalayas and the Tibetan plateau, researchers warn in the first comprehensive study to assess levels of organic pollutants in that part of the world. Persistent organic pollutants (POPs) are carbon-based compounds that are resistant to break-down. Some originate from the burning of fuel or the processing of electronic waste, and others are widely used as pesticides or herbicides or in the manufacture of solvents, plastics and pharmaceuticals. Some POPs, such as the pesticide dichlorodiphenyltrichloroethane (DDT) and the herbicide Agent Orange, can cause diseases such as cancers, neurological disorders, reproductive dysfunction and birth defects. The researchers found large amounts of POPs (including DDT) in various components of the ecosystems such as soil, grass, trees and fish in the Himalayas and in the Tibetan plateau, especially at the highest elevations."
Re:Article fail (Score:5, Informative)
High mountains may serve as “cold traps” for persistent organic pollutants (POPs) and ice cores can provide long-term records of atmospheric deposition of pollutants. In this study, DDT, hexachlorocyclohexanes (HCHs) and polycyclic aromatic hydrocarbons (PAHs) in an ice core from East Rongbuk Glacier were analyzed and the deposition fluxes of these pollutants were investigated. Concentrations of total DDTs reached maxima of approximately 2 ng l1 in mid-1970s, which is corresponding to the peak of malaria cases in India (in 1976). The decrease of DDT concentration after 1990s was in-line with the ban of DDT in India (in 1989). High level of -HCH was observed in early 1970s and it showed a decrease to undetectable level at the end of 1990s, which is in agreement with the period when India banned the usage of HCH (in 1997). Concentrations of total PAHs sharply increased after 1990 and the peak (approximately 100 ng l1) was found at the end of 1990s, when India entered the rapid industrialization (urbanization). PAHs in the ice core are dominantly pyrogenic in source, and are mainly from incomplete combustion of coal and biomass burning. Good correlations among concentrations of PAHs, nssSO42 and microparticles in snow pit samples showed that the origin of the PAHs and nssSO42 is often the same and they may be absorbed by particles and transported to high mountain regions by atmospheric circulation.
(please note that Slashdot does not support the superscript I just copied and pasted)
Also, my google fu turned up one of the original research articles [itpcas.ac.cn] that appears to be hosted for non commercial purposes only.
Re:How do we organic out of (Score:4, Informative)
burning of fuel or the processing of electronic waste? Everything is "organic". Nothing is man made besides god.
"Organic" is a term in chemistry. It refers to chemical compounds which contains the element carbon. For example, sulfuric acid is an inorganic compound, while methane is an organic compound.
Of course, you could have spent a whole 5-10 seconds Googling that instead of wallowing in your own ignorance and generally making an ass of yourself. I will never understand why people choose to be helpless when they have the means to easily and quickly inform themselves. The concept of "intellectual laziness" doesn't begin to answer this mystery. Perhaps some kind of deep-seated need for attention compels you to seek unnecessary hand-holding, but that is only a guess.
DDT gets a bad rap (Score:4, Informative)
DDT is villianized far out of proportion these days. Although admittedly they are both POPs, setting it rhetorically alongside Agent Orange as though they are the same is absurd.
DDT's carcinogenic properties are not really all that serious. We expose ourselves to more carcinogenic substances all the time, such as gasoline fumes. These minor effects were played up by DDT's opponents back in the day to scare people into accepting a DDT ban. Similarly, the acute toxicity is minor. To my knowledge, there's only one case where someone died from consuming DDT, and in that case the DDT may have contained other harmful chemicals.
On the other side of the coin, DDT saved millions of lives by eliminating malarial mosquitoes and other harmful insects. It easily saved more lives than it took.
Agent Orange on the other hand has caused awful damage in the areas where it was used extensively. If DDT was even close to as dangerous as it was made out to be by its opponents, then the present day impacts would be like a worldwide version of the Agent Orange boondoggle...times 1000.
First Study (Score:4, Informative)
I am sure this is a valuable piece of work, as it is claimed as the first of it's type and will be very useful as a benchmark. Analytic chemistry has progressed tremendously over the 40 years I was a practicing chemist, to the point where concentrations of particularly dangerous materials are possible to measure at femtograms per liter. At those concentrations you are detecting a very small number of molecules in a sample,
But since it's the first it really doesn't say much in terms of the progression of the state of affairs in these ecologies. It will be very interesting to see what the results are in a decade or two; whether the measures we are taking now to reduce the presence of these various very bad actors in the environment are being effected by environmental controls or not.
People greatly underestimate the versatility of Nature as a chemist. Some of the worst chemicals found in these studies are formed not only by man, but by Nature as well. For example DDT like chemicals have been found to exist in every evolutionary epoch.
http://books.google.com/books/about/Naturally_Occurring_Organohalogen_Compou.html?id=u45Z-kh61ngC [google.com]
http://books.google.com/books?id=S2fvZsZwgQ4C&pg=PA185&dq=naturally+produced+ddt&hl=en&sa=X&ei=p0FoUe69C6nD4APzwoGYBA&ved=0CDQQ6AEwAQ#v=onepage&q=naturally%20produced%20ddt&f=false [google.com]
Re:DDT gets a bad rap (Score:2, Informative)
Re:DDT gets a bad rap (Score:4, Informative)
I think you're forgetting the primary concern with DDT was birth defects, not cancer. Primarily in animal populations. ...and the fact that insects were becoming resistant to it anyway, in some cases.
Re:How do we organic out of (Score:4, Informative)
When you're talking about chemical compounds, the term "organic" has a very specific meaning, regardless of whether you're currently inside a lab or who you're talking to. This is the meaning used in the article summary.
If you were talking about a head of cabbage, then "organic" would have a very different, specific meaning, once again regardless of lab setting or listener.
This is how words work.
Re:DDT? (Score:5, Informative)
I worked for many years in vector borne disease surveillance. Most of what you have said is wrong or misleading.
DDT based mosquito "eradication" programs never eradicated any mosquito populations, because a single surviving gravid Anopheles mosquito can lay over two hundred eggs at a time. But malaria has a weakness that mosquito borne encephalitis does not have: most strains of Plasmodium have no significant enzootic reservoirs -- that is to say most strains that infect humans, infect humans exclusively. This means if you can eradicate human-to-human transmission, you eradicate the underlying infectious agent.
In the late 40s DDT *was* instrumental in eradicating endemic malaria in the US, but that was through over four million "domestic" treatments -- applications. These are treatments of the *interiors* of homes. In domestic applications, the DDT does not enter the food chain and does not bio-accumulate.
DDT is not magic pixie dust. It's not the only pesticide that works, and it is neither necessary nor sufficient for malaria eradication. It is, however, valuable. It is cheap, effective, and relatively long-lasting, which is a huge boon in domestic applications because it reduces the number of re-treatments you have to do. That same property of longevity makes it a very poor choice for agricultural use.
I attended a number of meetings where the prospect of using DDT for malaria eradication in the third world was discussed. The key problem is that many places where it is needed are desperately poor, and theft is rife. I knew plenty of researchers who had their field equipment stolen; some of them took to putting their computers and backups in a backpack and slept with it to keep from losing their data. There is a high risk of DDT being stolen and diverted to agricultural use, where its drawbacks come into play: under certain conditions it can persist in the soil for years, and it has a high potential to bio-accumulate, so even small concentrations can have effects on predatory animals. Furthermore runoff into water sources in sub-lethal concentrations has a high potential to create DDT resistance in target species including Anopheles, the vector of malaria. That could undermine attempts to eradicate a number of mosquito borne diseases other than malaria. This could have significant effects on attempts to control many mosquito borne diseases, malaria included.
Well, this is kind of a strawman argument. I've worked with people in the pesticide industry, in public health, and with environmental groups, and as far as I can see the images you mention here are entirely a figment of your own imagination. Everybody who studied this problem understand there are risks and benefits to using DDT, mainly they differ on how they weigh the risks.
In any case, if we knew that domestic DDT applications could eradicate malaria in an area back in 1950, why wasn't it eradicated worldwide? Because there's never been the political will to do that. There has never been a worldwide ban on DDT (which is why they're seeing way up in Tibet), so why hasn't it been eradicated in more places? Because there was never the political will to do it. If the will existed, we could do it, with or without DDT, just with somewhat less initial cash outlay for DDT.
Let me reiterate: DDT is not magic pixie dust. It *does* have potential to reduce the initial *cost* of eradicating malaria (except in SE Asia, where zoonotic forms of Plasmodium exist). But wherever malaria could be eradicated *with* DDT, it could also be eradicated with something else, say with synthetic pyrethrins. Pyrethrins have a very short half-life outdoors, reducing problems of pesticide resistance and bio-accumulation. The main drawback is that they also have a somewhat shorter half-life indoors, requiring more repeat treatments in the eradication phase. That'd still be a bargain in terms of human life.