[Catalist] A Study in Environmental Chemistry: Lead in portable Drinking Water [Updated]

[Michael McGarry]

A Study in Environmental Chemistry: Lead in portable Drinking Water

[Updated to include comment on how de-zincification of Leaded Brass fittings in pipes can release lead into portable water carried in pipes.]

Greetings Science Colleagues,

ABC URL: http://www.abc.net.au/news/2017-04-20/govt-to-pay-lead-contamination-fix-perth-childrens-hospital/8457388 <http://www.abc.net.au/news/2017-04-20/govt-to-pay-lead-contamination-fix-perth-childrens-hospital/8457388>
The above ABC online news report motivated me to conduct www research into the causes, distribution and degree of lead contamination in Australian drinking water. [There is a serious lack of Australian webpages informing lead in drinking water.]

Dosing of portable water with Phosphates

The dosing of portable water with phosphates can reduce lead contamination.

URL: http://orendatech.com/wp-content/uploads/2014/02/Potable-Water-Treatment-phosphates.pdf <http://orendatech.com/wp-content/uploads/2014/02/Potable-Water-Treatment-phosphates.pdf>
Does phosphate dosing provide a long-term solution to lead contamination of portable drinking water?

“Brass fittings to blame for lead scare: Government” [ABC news story]

“Mr Wyatt [WA State Treasurer] said it was the Government's view the lead contamination was a result of the de-zincification of brass fittings in the pipes.”

For Mr Wyatt’s statement to be possibly true, we must assume that the brass fittings installed in the plumbing at the new Perth Children’s Hospital must have been made from leaded brass?

Lead content in Brass

Brass can be lead free or leaded brass. Lead metal is added to brass to increase the machinability of the brass during manufacture of plumbing fittings, e.g., taps.

During the machining of leaded brass, thin layers of lead metal atoms concentrate on the surface of the leaded brass. These lead metal atoms inside leaded brass taps, especially hot water taps, can leach from the leaded brass into the portable water via the de-zincification of the leaded brass fittings.

De-zincification of leaded brass plumbing fittings

How does de-zincification of leaded brass plumbing fittings result in lead contamination of portable water? The following URL provides some answers.

VPISU URL: https://theses.lib.vt.edu/theses/available/etd-12182009-203827/unrestricted/Zhang_Y_T_2009.pdf <https://theses.lib.vt.edu/theses/available/etd-12182009-203827/unrestricted/Zhang_Y_T_2009.pdf> [Chapter 5 pages 112 -118.]

Do Australian Federal and State government regulations require the installation of lead-free brass fittings in the pluming of Hospitals? Stainless steel taps do not contain lead metal!

Lead affects brain development in children resulting in learning difficulty.

Mayo Clinic URL: http://www.mayoclinic.org/diseases-conditions/lead-poisoning/symptoms-causes/dxc-20275054 <http://www.mayoclinic.org/diseases-conditions/lead-poisoning/symptoms-causes/dxc-20275054>
Additional URL’s that inform causes and distribution of lead contamination in portable water.

URL 5: https://www.newscientist.com/article/2100806-lead-in-australias-drinking-water-is-leaching-from-brass-taps/ <https://www.newscientist.com/article/2100806-lead-in-australias-drinking-water-is-leaching-from-brass-taps/>
URL 6: https://www.sciencedaily.com/releases/2010/11/101111141849.htm <https://www.sciencedaily.com/releases/2010/11/101111141849.htm>
URL 7: http://dwi.defra.gov.uk/research/completed-research/reports/DWI70-2-287exsum.pdf <http://dwi.defra.gov.uk/research/completed-research/reports/DWI70-2-287exsum.pdf>
URL 8: http://vtnews.vt.edu/articles/2010/11/111710-engineering-edwardsunc.html <http://vtnews.vt.edu/articles/2010/11/111710-engineering-edwardsunc.html>
URL 9: http://www.tandfonline.com/doi/full/10.1080/02670836.2016.1220906 <http://www.tandfonline.com/doi/full/10.1080/02670836.2016.1220906>
Colleagues this e-post illustrates that when science is applied to explain real-life situations, the science is always from my secondary science teaching experience very complicated.

Best Wishes,

Michael John McGarry
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