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Blog #11
I’ll talk mostly about my research here. Well, we (we being
myself and my advisors and a PhD student at USF who is very involved with
Madagascar for his research) decided that it would be worthwhile to investigate
the possibility of lead leaching significantly into the water drawn from
Pitcher pumps. Lead can pose a serious problem for everyone, and is implicated
in illnesses including neurological development issues, cardiovascular
diseases, impaired renal function, hypertension, reproductive effects, and
suspected carcinogenicity (WHO 2011a,b). The risk is especially
urgent for children under 5. Even the most stringent regulations to date have
been recently linked to significant health impacts (WHO 2011b).
These particular pumps are pretty simple suction pumps that
are hammered into the ground after a sort of sludging method is used to remove
the first few meters of sandy soil. It has been used to supply household level
water for over 50 years in Madagascar with no subsidies. There are over 50 independent
pump manufacturers just in the Tamatave area. This is really impressive for a
self-supply market, and is the subject of some extensive research done by Mike
MacCarthy at USF.
Anyway, Meghan Wahlstrom and I started our research in
December to see what the water quality was like when varied across several
factors: Meghan looked at microbial quality; I looked at quality with respect
to heavy metals (lead).
Lead can leach from the solder and the well-screen, which
contain different percentages of lead in the alloys. We still have the same
problem in the US, but centralized water providers to prevent high lead levels
by controlling water characteristics (Triantafyllido & Edwards 2012). The
other place lead comes from is the check valves in the pump head, which is pure
(more or less) lead harvested from old car batteries.
To keep things brief, I’ll say that lead leaching is
significant in the pumps. We’d like to be able to suggest affordable ways for
people to mitigate this threat. One proposed solution, for example, is to flush a certain amount of water from the pump before drawing for consumption. Another potential solution is to replace the lead check valves in the pump head with iron.
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Mike and Meghan determining well depth with a local manufacturer and USF's research assistant Onnie. |
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Me looking at water quality with an instrument that totally
looks like Ghostbusters. |
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Leaded components for the well screen. |
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Leaded components for the check valves. Molten lead is cooling in an indention in the sand to the left. |
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Substitute for the lead valve weights is iron. |
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The portable instrument that lets me see lead content using Anodic Stripping Voltammetry. |
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Actually running a sample. |
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Meghan getting her "just desserts" after a day of research. I credit PCV Sam Irwin with the terrible pun. |
At this point, I’ve completed 2 trips to the east coast for
data collection. I will make another trip in July for a final round of data
collection, and to begin sharing pertinent results with stakeholders in
whatever ways are feasible for such a short time. I think that part of the
requirements for the MI program is to get our final thesis translated into the
language of the host country for PC service. That’s one way to further share
results. Anyway, that’s where things stand at the moment with research. It has
been going well and seems to be a worthwhile project.
I should also note here that in between my 2 research trips
a lot happened, one of which being that I was able to go home and see friends
and family for the first time in a year and a half for Christmas. That was
pretty great, and now I’m counting down from like 4 months before I’ll see
people again.
Triantafyllido, S. &
Edwards, M. (2012). Lead (Pb) in tap water and blood: Implications for lead
exposure in the United States. Critical Reviews in Environmental Science and
Technology. 42, 1297-1352
World Health Organization
(WHO), (2011)a. Drinking water quality guidelines, 3rd ed. Geneva:
World Health Organization.
World Health Organization
(WHO), (2011)b. Lead in drinking-water: Background document for
development of Guidelines for
drinking-water quality Rev/1. Geneva: World Health Organization.