Unintended Consequences

Today, let’s examine the strange case of a Mr. Thomas Midgley. I was doing one of my regular wanderings through the Wikipedia the other day, and somehow ended up reading all about CFCs and the depletion of the ozone layer, and all of that good stuff. I remembered that as entering freshmen at MIT way back in 1996, we were treated to a brief lecture on the topic by Professor Molina, who had just won a share of the 1995 Nobel Prize in Chemistry for explaining the link between CFCs and ozone layer depletion. But, I digress.

Back to Midgley now, he was working for a subsidiary of GM back in 1930 when he began work on developing a safe refrigerant for use in household appliances. You see, back then people used nasty things like ammonia or sulfur dioxide in their refrigerators, and people were dying and getting poisoned left and right from leaks.

What he came up with was a little compound known as Dichlorodiflouromethane, and an entire family of these chloroflourocarbons (CFC) with unique boiling points that can be used safely in any number of applications as propellants (e.g. aerosal cans), as well as refrigerants and cleaning solvents. At the time, understandably, he was hailed as a hero. Apparently, in a demonstration of the compound’s safety, he inhaled a breath of the stuff and then used it to blow out a candle. Of course we all know the rest of the story, how in the ’80s and ’90s scientists like Molina discovered a mechanism by which the CFCs, once inevitably released into the air, would destroy the earth’s protective ozone layer. You see, that’s a good example of unintended consequences. Here’s a genius engineer who comes out with an amazing invention, wins all sorts of awards, etc. and still ends up having to take at least part of the blame for the CFC/ozone debacle that we’re still dealing with to this very day.

Alas, that is not where the story ends with Mr. Midgley, however. Earlier in his career with GM, back in the roaring ’20s, he came up with another gem. Midgley discovered that adding a small amount of a chemical known as “tetra-ethyl lead” (TEL) to gasoline, thus making “leaded gasoline,” he could raise the effective octane level of the fuel and prevent engines from knocking. As with his CFC discovery, of course he won all sorts of awards and accolades. However, unlike the CFC issue, issues with leaded gasoline, pollution and lead toxicity arose early on, and indications are that Midgley actually was aware of problems. Dozens of workers in the factories that made TEL ended up falling ill, and in many cases dying. Midgley himself apparently suffered from a bout of lead poisoning. From tailpipe emissions contaminating soil and groundwater (especially in urban and highway-proximate areas), it’s estimated that about 68 million children had toxic exposures to lead from gasoline between 1927 and 1987. As many as 5000 americans died annually from lead-related heart disease prior to the phaseout of leaded gasoline. Since leaded gasoline is no longer in use, the mean blood-lead level of the American population has declined more than 75 percent. (citation)

Hero, or Villian? Midgley “had more impact on the atmosphere than any single organism in earth history.” He ended up contracting polio in 1940, and being the engineer that he was, he constructed an elaborate system of cables, rope and pulleys to get him in and out of bed. Ironically, that system was the cause of his death as he got caught up in it and was strangled at age 55. Unintended consequences, indeed!

Thomas Midgley
Paper on the discovery of Tetra-Ethyl Lead and Midgley’s lead poisoning
Another article about leaded gasoline. What did the makers know, and when did they know it?

  1. #1 by Mike on May 14, 2007 - 4:41 pm

    Good stuff. Very interesting. Mark J sent me an email calling this post “Blogging Hall of Fame stuff,” and I think I agree.

  2. #2 by amanda on May 16, 2007 - 9:03 am

    interesting story, benoc!

  3. #3 by MRhé on May 22, 2007 - 5:01 pm

    This is actually a very A-side blog entry. Interesting, well-written, full of…information.