Sunday, May 29, 2016

Get the lead out

Yard Sales provide a glimpse back in time, and in spite of my feeble efforts to rid myself of stuff, I relented and purchased a box of old National Geographic Magazines.

During the 1980s I had a subscription to this magazine and stored the issues in the attic. It is the type magazine that you would keep, When I places a box of those issues by the road with a free sign, the disappeared almost instantly.

So why, one might ask would I pick up another box? These are not just old, they are really old, dated from 1917 till 1928.

The issues show a world which has changed a bit over 88 to 90 years. The advertising is especially interesting such as these gems.

One innovation of the 1920s that was ill conceived was the addition of Tetraethyl lead to gasoline as an anti-knock fuel additive. It made gasoline engine more efficient. It also caused widespread lead pollution of the soil and water. By 2000 most (but not all) of the industrialized nations had discontinued it's use. The Wikipedia entry on Tetraethyl lead toxicity is especially sobering.

Lead pollution from engine exhaust is dispersed into the air and into the vicinity of roads and easily inhaled. Contact with concentrated TEL leads to acute lead poisoning.
Lead is a toxic metal that accumulates in the body and is associated with subtle and insidious neurotoxic effects especially at low exposure levels, such as low IQ and antisocial behavior.[42][43][44] It has particularly harmful effects on children. These concerns eventually led to the ban on TEL in automobile gasoline in many countries. Some neurologists have speculated that the lead phaseout may have caused average IQ levels to rise by several points in the US (by reducing cumulative brain damage throughout the population, especially in the young). For the entire US population, during and after the TEL phaseout, the mean blood lead level dropped from 16 μg/dL in 1976 to only 3 μg/dL in 1991.[45] The US Centers for Disease Control considered blood lead levels "elevated" when they were above 10 μg/dL.
Lead exposure affects the intelligence quotient (IQ) such that a blood lead level of 30 μg/dL is associated with a 6.9-point reduction of IQ, with most reduction (3.9 points) occurring below 10 μg/dL.[46]
Reduction in the average blood lead level is believed to have been a major cause for falling violent crime rates in the United States[47] and South Africa.[48] Researchers including Amherst College economist Jessica Wolpaw Reyes, Department of Housing and Urban Development consultant Rick Nevin, and Howard Mielke of Tulane University, say that declining exposure to lead is responsible for up to a 56% decline in crime from 1992 to 2002.[49] Including other factors that are believed to have increased crime rates over that period Reyes found that this led to an actual decline of 34% over that period.[50]
A statistically significant correlation has been found between the usage rate of leaded gasoline and violent crime: taking into account a 22-year time lag, the violent crime curve virtually tracks the lead exposure curve.[45][51] After the ban on TEL, blood lead levels in US children dramatically decreased.[45]
Although leaded gasoline is largely gone in North America, it has left high concentrations of lead in the soil adjacent to roads that were constructed prior to its phaseout. Children are particularly at risk if they consume this.[52] 

But first a word from our sponsor

National Geographic - April 1928
National Geographic Magazine - April 1928
Get the Lead Out
National Geographic magazine - October1928

Want more lead?

National Geographic - April 1928
April 1928 advertisement

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