Day: February 3, 2007

Arsenic in the News, US Edition

Byoliveridley

Boy, it’s all arsenic all the time on this blog!

Chemical & Engineering News: Latest News – In Katrina’s Wake, An Arsenic Threat

An incredible 72 million m3 of debris was created when Hurricane Katrina wreaked havoc in Louisiana and Mississippi in 2005. A survey of this debris now reveals that an estimated 1,740 metric tons of arsenic could leach into groundwater from unlined landfills where the materials are being disposed (Environ. Sci. Technol., DOI: 10.1021/es0622812).

Here’s EPA’s page on arsenic treated wood, and here’s the cheerleader page for same (mmm, industry advocacy websites, delicious!). Note that the EPA is currently working with the manufacturers to “voluntarily” phase out the use of Chromated Copper Arsenate in residential settings. Note that there are several alternatives available, all of them less toxic and equally effective. While this “voluntary” action limits direct exposure for certain types of people, old wood ending up in unlined landfills will overwhelmingly affect people who live near said landfills, namely the poor, and African American. 

Even lined landfills leak eventually, and while other organic matter may degrade before the leaking, arsenic and heavy metals are not going anywhere. Unlined landfills, which is a fancy way of saying hole in the ground where you throw trash in, are completely unacceptable in this day and age in a so called developed country like the US of A. On the other hand, it is fashionable to refer to Louisiana as a third world country, so I guess anything goes for those kinds of people, eh.

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Arsenic in the News

Byoliveridley

Professor wins $1M for arsenic filter – Yahoo! News

The National Academy of Engineering announced Thursday that the 2007 Grainger Challenge Prize for Sustainability would go to Abul Hussam, a chemistry professor at George Mason University in Fairfax. Hussam’s invention is already in use today, preventing serious health problems in residents of the professor’s native Bangladesh.

This British Geological Survey website provides a good primer to the problem. Some key points:

  1. Arsenic is very toxic
  2. Arsenic is naturally occurring in the shallow groundwater aquifers of Bengal and Bangladesh at a toxic level
  3. The surface water is contaminated with bacteria and was responsible for high infant mortality, so aid agencies in the ’70s encouraged the use of tube wells and other groundwater pumps. While this contributed to a decline in infant mortality from gastrointestinal infections, it also dosed unsuspecting people with disease causing levels of arsenic
  4. The technology for removal of arsenic is very well known. But most solutions require electricity/periodic maintenance/technical skills and are thus not universal or sustainable.
  5. Simplicity is the key. You can’t tell the people to not drink the water, it is the only clean water available. You can’t install water treatment plants, there is no running water, you can’t rely on solutions that are centralized.

So with all that in mind, here’s what Prof. Hussam did:

The Gold Award-winning SONO filter is a point-of-use method for removing arsenic from drinking water.  A top bucket is filled with locally available coarse river sand and a composite iron matrix (CIM).  The sand filters coarse particles and imparts mechanical stability, while the CIM removes inorganic arsenic.  The water then flows into a second bucket where it again filters through coarse river sand, then wood charcoal to remove organics, and finally through fine river sand and wet brick chips to remove fine particles and stabilize water flow.  The SONO filter is now manufactured and used in Bangladesh. That’s great, and easy!

That’s pretty much freshman chemistry right there, further proof that most innovation does not need new science, only people willing to spend some time on problems that don’t necessarily get looked at.