Lead in the Environment - PowerPoint Presentation

Slide1

Lead in the Environment

Unit 1

,

Class 2

: Occupational Exposures

Lead in pre-industrialized timesRoman era, I Lead is one of first metals humans learned to use due to ease of extraction, ductility

Lead toxicity first documented as early as 2

nd

century, BCE

Acute effects (paralysis, saturnine colic) associated with high-dose lead exposure

Nicander

of Colophon, Hellenistic physician

Not defined clinically; lack of interest in disease possibly due population exposed – typically artisans who were low socio-economic class

Lead in pre-industrialized timesRoman era, II1st century BC, expanded use of lead due to Roman conquest of Britain, where ore

was rich

in lead

Common lead exposures

Lead in water

Water and sanitation pipes very sophisticated, and lined with lead!

But… water heavily mineralized with calcium carbonate, which would have coated pipes and formed strong protection against release of lead salts

Lead in wine

Wine used

sapa

, a reduction of must (grape juice reduced to a syrup), that was prepared in lead containers

Lead acetate (also called “lead sugar”) used to sweeten low quality wines

Wines also stored in lead-lined amphora

Lead in pre-industrialized timesRenaissance era, IOccupational use of lead by artisan class (which earned greater respect in this period):

Artists (use of

cerussite

, also known as lead carbonate or “white lead”)

Fine metalworkers,

especially

goldsmiths

Alchemists

Possible victims of lead poisoning

Piero

della

Francesca (c. 1416-1492)

Rembrandt (1606-1669)

Francisco Goya (1746-1828)

Lead in pre-industrialized timesRenaissance era, IIIncreased understanding of occupational lead toxicity Ulrich Ellenbog

, German physician, 1440-1499, guided metalsmiths to not breathe in metal fumes

Georgius

Bauer

(also known as

Agriciola

), Saxon physician, 1494-1556, studied health problems of German miners

Paracelsus

, German-Swiss physician, 1493-1541, Use of lead as pharmaceutical, “Dose makes the poison” (contested)

Samuel Stockhausen

, German physician, 1656, advised German miners to avoid aspiration of dust

Bernardino

Ramazzini

, Italian physician, 1633-1714, identified all lead processes for metalworkers, and all mining activities, as dangerous, resulting in palsied hands, abdominal colic, fatigue, cachexia,

edentulism

(loss of teeth)

Lead in pre-industrialized timesNon-occupational etiology of lead Lead exposure from ingestion:Eberhard

Gockel

, German physician, 1636-1703, linked “

colica

pictonum

” – an intensely painful disease involving GI tract frequently resulting in death – to lead levels in wine

Sir George Baker

, British physician, 1722-1809, linked “Devonshire

cholic

” to ingestion of lead

Johann Peter Frank

, German hygienist, 1745-1821, recommended avoiding water flowing from lead pipes

Lead in industrialized eraLinking lead exposure to symptomsLouis Tanquerel des Planches, French physician, 1810-1862, examined 1200 cases of lead poisoning at

Hôpital

de la

Charité

, Paris, finding disease more common in those working with lead fumes than solid lead, and identified neuropsychiatric manifestations of lead poisoning

René Laennec

, French physician, 1781-1826, identified anemia with occupational exposure to lead

Henry Burton

, British neurologist, 1799-1849, identified blue-purple line along

gumline

as symptom of occupational exposure to lead

Sir Alfred Baring

Garrod

, physician, 1819-1907, linked occupational lead poisoning to gout

Jean-Étienne Dominique

Esquirol

, 1772-1840,

and then

Daniel Hack

Tuke

, 1795-1833, both documented mental disorders associated with chronic low-dose occupational exposures of lead

Lead in the industrialized eraOccupational protectionsCharles Turner Thackrah, British advocate, 1795-1833, efforts to improve worker conditions resulted in legislation to remove and replace harmful agents in the production cycle

Children forbidden to work in white lead factories in Britain, 1878

Factories Act: Prevention of Lead Poisoning

, 1883, British Parliament took steps to reduce exposure within occupational setting

White Lead Painting Convention

, International Labor Office, Geneva, 1921, treaty to ban indoor use of paint (not ratified by Britain or US)

Lead Poisoning and Lead Absorption

, Treatise by Sir Thomas Morrison

Legge

, 1863-1932, and Sir Kenneth Weldon

Goadby

, 1873-1958 on occupational risks from lead exposure

Modern eraChildhood exposure to lead paintChildhood exposure to residual lead has brought about key scientific and legislative advances1887: US first documents childhood lead

poisoning.

1904: John Lockhart Gibson, Australian physician, 1860-1944, childhood lead poisoning linked to domestic lead exposure from leaded

paints.

1909: France, Belgium, Austria ban use of white lead interior

paint.

1914: Australia restricts use of lead in

paints.

1922

: League

of Nations bans white-lead

interior

paint.

US

declines to

adopt.

1922:

Tunisia and Greece ban white-lead interior

paint.

1926: Great

Britain, 

and

Sweden, ban white – lead interior

paint.

1927:

Poland bans white lead interior

paint.

1931: Spain

and Yugoslavia ban white lead interior

paint.

1978: US bans lead in interior

paints.

Modern EraExposure to lead from gasolineCorporate interests, weak US economy, and wartime needs stymied US efforts

1920: General Motors engineer Thomas

Midgely

, Jr. (1889-1944) identified anti-knock effect of tetra-ethylene lead (TEL) when added to gasoline and formally introduces leaded gas into commercial sales

1923:

First tetraethyl lead poisoning deaths

occur

1980: National

Academy of Sciences calls leaded gasoline greatest source of atmospheric lead

pollution

1980s-90s: Benzene used to replace TEL in gasoline

1986: TEL banned from gasoline for cars and trucks in US

1995: TEL banned from all US land vehicles (airlines still exempt)