Patterson and Kehoe, and the great lead debate

You know what is really impressing me about Neil deGrasse Tyson's Cosmos? That he doesn't hesitate to draw connections between science and how we live our lives — there is an implicit understanding that science has become fundamental to how we see the universe. Last night's episode was no exception. What started as an explanation for how we know the age of the earth (4.55 billion years), as established by the rigorous measurement of the ratio of lead to uranium in meteorites by Claire Patterson, became an exploration of health and the misuse of science, as personified by Robert Kehoe.

Patterson was an expert in analyzing trace elements; Kehoe was a doctor who was in the pocket of the petroleum industry. Patterson saw rising levels of lead in the environment as a consequence of its use as a fuel additive; Kehoe was getting paid to sow doubt. Patterson focused on the effects of environmental lead on human health; Kehoe was more concerned with the profit margins of industry. The campaigns for lead additives in fuel resemble the abuses of science used to promote cigarette smoking and to fight actions to curb greenhouse gases. I dug up a review from the 1990s by Jerome Nriagu, and it also reminded me of something else: the damned limited perspective of proper science by the non-scientists in the skeptics movement.

Here's the first part of the abstract.

In 1925, Robert A. Kehoe enunciated a paradigm predicated upon categorical distinction between expectations and conjecture ("show me the data" mentality) from hard scientific facts on exposure outcomes. It led to a precedent-setting system of voluntary self-regulation by lead industry as a model for environmental control and implicitly signaled the level of industrial responsibility for lead pollution.

"Show me the data"? What could be wrong with that? Isn't that what we're supposed to do?

What that attitude fails to do, though, is to recognize degrees of uncertainty -- that we don't have absolute knowledge, but that all of our information comes with two measures: here's what we're pretty sure is true, and here's a measure of variability or uncertainty to give you an idea of the bounds of our confidence. So Patterson measured the age of the earth at 4.55 billion, ±70 million years (that bound is now down to around 20 million years). The uninformed or the devious can choose to emphasize that uncertainty of 70! Million! Years!, which is a very long time, while the scientists are looking at the 4.55 billion part.

That is the Kehoe Paradigm: emphasize the noise in the data. Talk about nothing but the variability. Make it sound like the scientists are baffled by their own data, simply because they are aware of the limitations of their knowledge.

Cosmos was relatively gentle with Kehoe; he was clearly the villain of the story, but it didn't make a big deal of the fact that he was a paid hack of the oil industry who was hiding the evidence in the name of profit. Well, not as big a deal as they could have, anyway — Kehoe was enabling world-wide environmental poisoning.

Here's the rest of that abstract.

It combined a cascading uncertainty rule (there is always uncertainty to be found in a world of imperfect information) with a highly skewed cost-benefit concept (immediate benefits of tetraethyl lead additives must be weighed against possible future health hazards). Many studies were funded by the lead industry to develop a theoretical framework for the paradigm which served as a strong defensive strategy against lead critics. It resulted in an unfettered growth in automotive lead pollution to over 270,000 tons per year in the United States and 350,000 tons per year worldwide during the early 1970s. Clair Patterson is credited with being the first person to mount an effective challenge against the Kehoe paradigm, and with his success came an upsurge of activity and attention to the risks of environmental lead pollution on public health.

That should sound familiar: multiply uncertainty, and balance it with a biased cost-benefit analysis. How libertarian!

Maybe not all of you remember the 1960s-1970s, but I do: I remember the ads everywhere touting one brand of gasoline that put a "tiger in your tank!" I didn't know at the time that the tiger was tetraethyl lead, and that a rather nasty environmental toxin, in addition to the carbon monoxide and carbon dioxide, was pouring out of everyone's exhaust pipes.

The heart of the Kehoe Paradigm was to first piously state that if it could be conclusively shown that tetraethyl lead was a public health danger, then of course the lead industry would stop, as the only rational and morally acceptable response. But then he would go on to argue that it wasn't conclusive at all, yet -- so the default response should be to allow industry to continue to profit until the consequences to public health were undeniable. And this neglect of responsibility was all neatly wrapped up in the claim that it was the "scientific" way of thinking -- that somehow, science only deals with absolute truths and that you can't draw scientific conclusions until every detail is knitted up with complete certainty.

The signals that this was all wrong should have been recognized early. Science is about a gradual convergence on a truth, and we make provisional statements about reality that are always subject to revision. If the preponderance of evidence leans one way (and that breathing tetraethyl lead was bad for humans was rather obvious), the onus is on dissenters to provide strong counter-evidence…not to natter on about what the scientists don't know for sure. Need I point out that this is also familiar creationist strategy, that rather than actually providing a coherent theory and supporting body of evidence, they'd rather go on and on about our areas of uncertainty?

But also there was another obvious problem. Kehoe was bought and paid for.

Robert Kehoe and the lead industry were very closely entwined in more ways than just the theory and practice of occupational health protection -- the lead industry built and equipped a laboratory for him, paid his salary (minus the $1.00 per year he received from the University of Cincinnati), and financed most of his research. The return for the symbiosis included an unprecedented control on research and knowledge about occupational and environmental lead hazards and the stifling of environmental pollution control programs in the United States for many decades.

I'm sure you'll be pleased to know that this villain lived in prosperity and prestige to the ripe old age of 99, dying in 1992, after a lifetime spent making sure that Big Oil could freely poison all the children in the country.

Another approach of the Kehoe Paradigm was to emphasize "thresholds". A little bit of poison is OK; it's only when it reaches some particular threshold that it becomes bad for you, and as long as the industry doesn't cross that line, it is doing you no harm. In the case of lead, Kehoe argued that the threshold was 100 µg/m3 — which is a hell of a lot of lead. It's also not true that there is a "threshold". I recall getting harangued by my old genetics professor, George Streisinger, who had been testifying for the Downwinders (people who had been exposed to fallout from nuclear tests), that there is no such thing as a threshold for radiation exposure -- it's a continuous sliding scale of increasing probability of damage with increasing dosage. But if you draw an arbitrary line, sanctify it with the label of science, and say anything below the line can't hurt you…well, Science says it's safe, so it's fine. Unfortunately, the evidence doesn't say any such thing.

Patterson really was a hero, and I was happy to see Cosmos give the man credit. He used evidence to fight against Kehoe; for instance, he did measurements (as shown on the program) to show that pre-industrial levels of lead were 0.0005 µg/m3, in contrast to the modern American levels of approximately 1µg/m3 — we were breathing in 2000 times as much lead now. To argue that the lead industry was not making a massive contribution of poison to the environment was raw nonsense.

He also found fault with the whole "threshold" idea. The clinical responses to acute lead poisoning were just an extreme on a continuum -- he speculated that "below the then accepted threshold concentration there were some effects which clinically might be difficult or impossible to detect or ascribe to their real cause."

But he also emphasized the problem of bias. "You can use the data to justify your purposes. If your purpose is to sell lead alkyls, then you look at these data one way. If your purpose is to guard public health, you will look at this data in another way, and you will reach different conclusions." Ataxia, coma, convulsions, and death are easy to diagnose, so using those as markers for a threshold may be convenient, but it ignores the subtle neurological effects, which might be important, too. Perhaps it isn't surprising that crime levels have been in decline since lead emissions were limited (this is another case of a purely correlational measure, but let's not ignore it -- we've removed a neurological poison from the atmosphere, and simultaneously see a shift in human behavior? Reasonable mechanism, measurable response, worth pursuing more).

Patterson testified before congress, as shown on Cosmos, and really chewed out industry and Kehoe for their misappropriation of science.

It is clear, from the history of development of the lead pollution problem in the United States that responsible and regulatory persons and organizations concerned in this matter have failed to distinguish between scientific activity and the utilization of observations for material purpose. [such utilization] is not science…it is the defense and promotion of industrial activity. This utilization is not done objectively. It is done subjectively. … It is not just a mistake for public health agencies to cooperate and collaborate with industries in investigating and deciding whether public health is endangered—it is a direct abrogation and violation of the duties and responsibilities of those public health organizations. In the past, these bodies have acted as though their own activities and those of lead industries in health matters were science, and they could be considered objectively in that sense.

Patterson eventually won on this one specific issue, and we're no longer burning tons and tons of lead. I wish I could say he'd won on the broader principle, though, because he didn't — the Kehoe Paradigm is still the standard pseudoscientific approach used by industry to justify great evils. For instance, CEI is arguing that we shouldn't expand regulation of industrial chemicals just because of a little ol' spill in West Virgina with a slew of half-truths…including the claim that MCHM has "low toxicity". It's the threshold argument again.

We're still trying to unravel the tangle he made of science policy, though. Kehoe's Paradigm lives on at various right-wing think tanks, for instance, the Heartland Institute, where the headline that greeted me when I just visited was Climate Change Reconsidered, which concludes that the human effect is likely to be small relative to natural variability, and whatever small warming is likely to occur will produce benefits as well as costs. Change climate change to environmental lead, and it could be straight from Kehoe, and is just as honest.

At least Cosmos is making an effort to show that good science matters, and matters everywhere in your life.


Nriagu JO (1998) Clair Patterson and Robert Kehoe's paradigm of "show me the data" on environmental lead poisoning. Environ Res. 78(2):71-8.

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It's not so much that there aren't reasonable thresholds as that the thresholds chosen are ludicrously high.

Perhaps my favorite is formaldehyde. No two ways about it, the stuff has nasty physiological effects and we need to be careful about introducing it both to our bodies and our environments. On the other hand ... our livers produce it continuously and there's a bit of it in blood and other tissues no matter how little we eat, drink, or breath. Setting an environmental limit so low that its impact on physiological concentrations can't be measured just might be overdoing it.

The same goes for radiation (or urine in your reservoir) -- once you get anthropogenic exposure down an order of magnitude or so below the background level, you're probably overdoing it.

By D. C. Sessions (not verified) on 21 Apr 2014 #permalink

You wonder what the mentality was for someone like Kehoe. Was he just an unabashed, amoral sell-out who was happy to provide a back-stop for industries generating environmental lead pollution as long as it meant he kept a good salary and his own laboratory? Was he some kind of stodgy libertarian crank who believed his theories and found a backer who shared his belief?

In any case, he was bad news - and I think the "lead leading to crime" hypothesis is pretty good. It helps that you see something similar happening in other countries that have massive lead pollution followed by cutbacks.

In any case, he was bad news – and I think the “lead leading to crime” hypothesis is pretty good.

IIRC it even works down to regional levels if you correlate crime stats to where the criminals were children -- including children from upper SES backgrounds who lived downwind of high traffic and other lead pollution sources.

By D. C. Sessions (not verified) on 21 Apr 2014 #permalink

Setting an environmental limit so low that its impact on physiological concentrations can’t be measured just might be overdoing it.

OTOH, this is how we found out that radon in basements is a hazard. As I recall the story, a nuke plant worker in Pennsylvania was always setting off exposure alarms at the plant, no matter how careful he was. One day, on a whim, he suited up and then immediately walked through the detector, triggering the alarm. So they checked out the guy's house, and there it was.

By Eric Lund (not verified) on 21 Apr 2014 #permalink

I remember as a kid -- 1950s or 60s -- seeing full-page ads -- in Scientific American, I think, since that came to our house -- showing a strip of pavement and grass along the side and the assertion that lead from automobile exhaust all stayed within a few feet of the road's edge. Been looking for those recently. Anyone else remember them? I forget which gasoline company they advertised.

By Hank Roberts (not verified) on 21 Apr 2014 #permalink

I remember as a kid -- 1950s or 60s -- seeing full-page ads -- in Scientific American, I think, since that came to our house -- showing a strip of pavement and grass along the side and the assertion that lead from automobile exhaust all stayed within a few feet of the road's edge. Been looking for those recently. Anyone else remember them? I forget which gasoline company they advertised.

By Hank Roberts (not verified) on 21 Apr 2014 #permalink

I’m sure you’ll be pleased to know that this villain lived in prosperity and prestige to the ripe old age of 99

It was all that damned lead!

Patterson is a world Hero!
We need someone like him today to help save our waterways

By ChesapeakeGem (not verified) on 21 Apr 2014 #permalink

Does anyone know if Kehoe ever apologized for or retracted anything he said or published? If he lived that long maybe he saw the light?

By Tiktaalik (not verified) on 21 Apr 2014 #permalink

Don't be surprised if the Kehoe backstory becomes the lede for a sucker punch-up of Midgeley, who turned from adding ethyl bromide to gasoline to held get all that lead out the tailpipe to inventing the chemically related CFC's that led to the ozone hole-- it's pratically a self-assembling Connections script

A very well thought out and specific summation of the last Cosmos episode. Nice connection @Russell.

By Dimitrios Papa… (not verified) on 22 Apr 2014 #permalink

This has been an amazing learning curve for me. Watching Cosmos and reading your comments on the Patterson/Kehoe controversy was fascinating. I remembered the ads of the 60's, "putting a tiger i your tank', as well as the campaign against led in paint, the link to substandard housing in the slums using paint with led and how it related to inner city children s learning problems.
Are there any books that cover this amazing history?

By Daniel del Valle (not verified) on 22 Apr 2014 #permalink

"Kehoe was enabling world-wide environmental poisoning."

That's where the parallel between the tobacco industry and the gas industry - otherwise quite apt - no longer shines. Tobacco use quite disproportionately affects the user, and even second-hand (and third-hand) smoke is a relatively direct and clear of effect (a chain of custody, if you will, of ill effects).

Leaded gasoline, on the other hand, has poisoned the very soil, and the actual long-term effects (especially in developing nations) may well be incalculable.

I often wonder what damages we have truly caused ourselves - and our children - in the name of profit. Then I have another beer, because damned if there aren't a whole lot of unknowable damages out there. ;)

I searched for the reference at the end of Dr. Myers' article and found it available for $41.95 on ScienceDirect. Anyone know of another (less expensive!) source?

Simply write to the authors and ask them for the pdf.

Remember, authors don't get any royalties or anything from having their papers sold by a commercial publisher. We're not paid for publishing; we have no interest in paywalls, only the publishers do.

Yes, it's weird. That's why open access is the future and increasingly the present.

By David Marjanović (not verified) on 25 Apr 2014 #permalink

@ Hank Roberts #7

I was one of the people measuring roadside lead levels when I was an undergrad at Caltech back in the 70's, and there is some truth to this. The lead aerosols did in fact mostly settle out within a few feet of the roadway, but the lead levels there were so tremendously high I felt like running away in terror. You just knew that that stuff was going to be easily mobilized.

Of course, at this point in time, you could not always see to the end of the block in Pasadena because of the smog, and there was no point in buying expensive tires because they would rot before they wore out anyway. There are still environmental problems of course, but we have come a long way.

By CherryBombSim (not verified) on 25 Apr 2014 #permalink

NFL v Concussions; Cigarettes v Cancer; Science v Lead Industry...will it ever end?

While thresholds aren't a bright line, the model of linear response to dose probably also isn't right. Some toxins stimulate growth in small quantities and kill in larger quantities. In the case of radiation, there is a significant natural variation in exposure between high altitude cities such as Denver and low altitude cities, and small additional doses to a resident of LA could well result in less total dose than a resident of Denver is naturally exposed to.

Patterson was absolutely right about about lead, but he found several orders of magnitude more lead than in preindustrial times. Dosage makes the poison. Cosmos could have done a better job of explaining this, for example by numerically describing background lead levels, increase in exposure due to TEL and other sources, and current levels.

By Jim Christian (not verified) on 27 Apr 2014 #permalink

I regard Kehoe as a by theoil -industry paid criminal.
Even after all the evidence of the ledproblemen/contaminations Kehoe just ignored everything.
In the end, you could not even call him a scientist.
Just a fraud.

I really, really think it's important to do a lot of hard stomping on Dr. Kehoe's face, and his memory. It's important to drag his name through the filth he dumped all over this world .

It's not 100% certain to leave a mark for future would-be prostitutes of science to see, but it sure would help, i think, in dissuading some folks from glibly falling in line.

Maybe we could also get a start in kicking Stephen Milloy, who's a modern day Robert Kehoe, and make it so he can't open up a web page without seeing his name slopped in his own crap.

Do I sound harsh? Well, lead poisoning is f-ing harsh. I don't know if financial punishments can work for this, but maybe we can use simple shame. These people are beneath contempt. They're not doctors. They're not scientists. They're prostitutes. Let's call them what they are. For sale.

if you think academia has learned anything, Google Dr. Robert Kehoe and click on The Society of Toxicology discussion of his career.

The controversial debate concerning the lead industry makes individuals, such as myself, question the intentions of the so called informed scientific community. At what point is it justifiable for the concerns of a neutral community to be ignored (by an individual such as Kehoe) in an attempt to convince the neutral audience that the views of the specific individual are correct. There is an imbalance of power that is not always advantageous on a larger scale.

Kehoe claims that lead presents little danger to people as it is a natural part of the human environment and people have developed mechanisms to excrete lead once inhaled or ingested.

A survey “Public Knowledge and Attitudes on Lead” conducted by the “Opinion Research Corporation” showed that 42% of the public viewed lead as one of the ten substances harmful to health. Lead was ranked second to carbon monoxide in America’s perceptions of risk.
Although this is based on perception, one should not entirely disregard the views of the affected public. There is underlying logic in their arguments.

Also, it cannot be justified that there is a threshold for the danger of lead. Taking the broad range of individuals into account, one cannot pinpoint at what exact point the lead poses a threat to health. Age, gender and health status are factors that influence these statistics. The views of the neutral community should thus be taken into account.

The “Society of Toxicology” discusses this in more depth as mentioned by @Rick. I found these sources highly informative.

It would be nice if people did not recklessly merge the idea of uncontrolled environmental destruction with libertarianism. In truth, they are incompatible.

In a libertarian world, persons and businesses would be held responsible for the damage that they cause. Kehoe and his cohorts would likely have been imprisoned, and he and the companies involved would be paying restitution and working to clean up the mess they caused.

Cronyism and corporate capitalism - an economic system in which corporations enjoy special privileges, and well-connected persons (cronies) are rewarded - deserve the scorn, not libertarianism. Libertarianism (free-market capitalism) requires that everyone be responsible for their actions.

In a libertarian world, persons and businesses would be held responsible for the damage that they cause.

Who by?

Who can hold a sovereign corporation responsible for anything? The lawyers it pays? The legislators whose campaigns it has financed?

A libertarian world would live by the golden rule: the one with the gold makes the rules.

Cronyism and corporate capitalism – an economic system in which corporations enjoy special privileges, and well-connected persons (cronies) are rewarded – deserve the scorn, not libertarianism.

Intended or not, they are an inevitable outcome of libertarianism.

Libertarianism (free-market capitalism) requires that everyone be responsible for their actions.

That's exactly why it doesn't work.

By David Marjanović (not verified) on 02 May 2014 #permalink

Max: "Insulting" someone by calling them a prostitute is itself a case of contemptible slut-shaming. It's too bad there's no quick word (that I can think of) that basically means "Person who would commit any evil at all for the right price", but that's no excuse to talk in sexist terms. Selling one's sexual activity isn't shameful at all, but selling the world's health is.

This has been an amazing learning curve for me. Watching Cosmos and reading your comments on the Patterson/Kehoe controversy was fascinating