Nicolas Cantarero Environmental Studies Chemistry Emphasis

Metal Highly Toxic Gasoline, paint, pipes, solder, bullets Gold and silver Fall of Rome Why lead?

Durable Corrosion resistance Expands with water Freeze-thaw cycle Easily reparable Easy/cheap to make Highly malleable Easy to smelt

Leaches into water from corroded plumbing materials and water service lines Especially if water has been sitting in tap for more than 6 hours Monitored by EPA under SDWA (1974) Lead ban came into effect in 1992

SDWA sets maximum contaminant levels MCL for Lead is 15 ppb (too low for Flame AA) 2006 Annual Drinking Water Report: 5 ppb City wide average Can be misleading Low income neighborhoods

Short Term Effects:  Red blood cell interference  Delays in normal physical/mental development in children  Deficit in attention span  Increase in blood pressure  Hearing deficiencies Long Term Effects:  Short term effects  Stroke  Kidney Disease  Cancer

Absorbs into red blood cells and plasma Redistributes into bones and soft tissue Long residence time in bones and tissue, 10 year biological half-life Neurotoxin

Synthesize Hydroxyapatite

Mineral Ca 10 (PO 4 ) 6 (OH) 2 Makes up 70% of our bones Calcium hydroxide and phosphoric acid 10Ca(OH) 2 + 6H 3 PO 4 Ca 10 (PO 4 ) 6 (OH) H 2 O Very cheap to make High surface area Binds well to lead

Once Hydroxyapatite is synthesized bind with the lead Column (1g HA) Dissolve in Nitric acid (Conc/10%) Run on Flame AA Make standards (15 ppb) Compare unknown to standards

Laminar flow burner Air-acetylene flame Hollow cathode lamp (Pb) nm Detection Limit.1 mg/L

SamplePpb Corrected Corrected Corrected Corrected 424.8

SamplePpb

Sensitive Accurate Cost Per sample Instrument Speed Ease and availability of equipment Skill of operator required