Sunday, December 09, 2007

The delayed evidence

For more than 40 years, automobile makers, oil companies and additive manufacturers kept denying that tetraethyl lead was a serious health hazard, until a scientist named Clair Patterson hit upon a method to produce the evidence and create an awareness that ultimately led to the phase out of the chemical.

The whole story is narrated by Alan Bellows in his blog, “Damn Interesting”. Bill Bryson had also devoted an entire chapter to this subject in his best-seller, “Short History of Everything” and Alan Bellows acknowledges that his own research on the subject was inspired by that book.

The story underscores the point that it can take years or decades for clear evidence to be found, but where reasonable suspicion exists ( as it did in the case of tetraethyl lead), it is best to proceed with utmost caution, before commercializing or mass-producing anything. Alas, as we see too often, when corporate interest and profit motive become the prime drivers, reason and sanity take the back seat.

The same is true for carbon emission. There are many who feel that the whole thing has been hyped up, that no climate change has taken place or, even if it has, it is due to a natural cycle and not due to CO2, etc. Commercial interests and the lobbying power of coal producers and thermal plants keep obfuscating the whole issue. There are bloggers such as this one, who debunk the whole theory of global warming and seek out material to justify their stand. Even making allowance for different opinions to co-exist, the point is, while one can’t obtain clinching evidence to ground the theory, there are enough pointers and adequate measurements to validate the fear of irreversible climate change and to raise the red flag.

Two other interesting snippets from Alan Bellows.

1) That Thomas Midgley, who had developed the lead additive was also, in later years, the brain behind the invention of chlorofluorocarbons that caused enormous damage to the ozone layer, before they were banned. The guy was certainly talented.

2) That there is a correlation between high lead levels in the atmosphere and the crime rate. The sharp decline in US crime rates which began in the early 1990s dovetails perfectly with the reduction of leaded gasoline in the early 1970s; and other countries which followed suit saw similar declines, also delayed by twenty years. (Curiously, in the book Freakonomics, the author Steve Levitt had attributed the reduction in crime rate in the same period, to the legalising of abortion.)

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