Beijing Smog: Good or Bad?

I am in Beijing. The smog is bad. It is more humid than usual and the air is dirtier than usual. At his blog, James Fallows, who is also in Beijing, has posted  pictures and pollution measurements. (Incidentally, Eamonn Fingleton, an excellent writer, will be guest-blogging there. In Praise of Hard Industries is one of the best business/economics books I’ve read.)

The effect of smog on health isn’t obvious. Maybe you know about hormesis — the finding that a small dose of a poison, such as radioactivity, is beneficial. It has been observed in hundreds of experiments. It makes sense: the poisons activate repair systems. Even if you know about hormesis, you probably don’t know that one of the first studies of smoking and cancer found that inhaling cigarette smoke appeared beneficial: inhalers had less cancer than non-inhalers. R. A. Fisher, the great statistician, emphasized this (pp. 160-161):

There were fewer inhalers among the cancer patients than among the non-cancer patients. That, I think, is an exceedingly important finding.

This difference (a negative correlation) appeared in spite of two positive correlations: Heavy smokers get more cancer than light smokers; and heavy smokers are more likely to inhale than light smokers. It is far from the only fact suggesting the connection between smoking and health isn’t simple.

So I am not worried about Beijing smog. The real danger, I think, is not eating fermented foods. Which, thankfully, is infinitely more under my control.

13 Replies to “Beijing Smog: Good or Bad?”

  1. One of the most fascinating anecdotes regarding stress and recovery is in this excerpt from the book Spark: The Revolutionary New Science of Exercise and The Brain:

    “In the 1980`s the U.S. Department of Energy commisioned a study on the impacts of sustained radiation exposure. They compared two groups of nuclear shipyard workers from Baltimore who had similar jobs except for a single key difference: one group was exposed to very low levels of radiation from the materials they handled, and the other was not. The DOE tracked workers between 1990-1988, and what they found shocked everyone involved. Radiation made them healthier. The 28,000 workers exposed to radiation had a 24% lower mortality rate than their 32,000 counterparts who were not exposed to radiation. Somehow, the toxins that everyone assumed and feared were ruining the workers were doing just the opposite. Radiation is a stress in that it damages cells, and at high levels it kills them and can lead to the development of diseases such as cancer. In this case, the radiation dose was apparently low enough that instead of killing the cells of the exposed workers, it made them stronger. Neuroscientists call this phenomenon stress innoculation.”

    I often wondered how this phenomenon transferred to vices like light smoking and drinking, and as you pointed out, exposure to air pollution. It’s a fascinating discussion, but when I’ve ever brought it up in conversation, people look at me like I’ve lost my mind. Definitely not a politically correct topic, especially for anyone who’s lost a friend or family member to cancer (most people).

  2. Thanks, Sean. I didn’t know about that study, which is an especially good one. It is newly relevant in light of concern about the health effects of airport screening. I think the explanation the author gives is a bit off (the radiation “made cells stronger”). The usual explanation of radiation hormesis is that the damage caused by radiation activates repair systems. This is temporary. When the activation wears off, so does the protective effect. “Made cells more vigilant” you could say.

  3. You have the Fisher quote wrong. It’s “And the result came out that there were fewer inhalers among the cancer patients than among the non-cancer patients.” Which fits a little better with your point.

  4. Yes, the anti-smoking science is very weak.

    However, anecdotally I believe that the new chemically processed cigarettes are very bad… I develop a cough whenever I use them, and start feeling crappy.

    When I was in Beijing, my lungs burned. You see a lot of people there with bad coughs.

    I smoke handrolled cigs of pure, reasonably moist tobacco and it’s quite smooth, no lung troubles.

    There’s no animal science supporting the link between cancer and smoking; the studies instead all showed major health benefits.

  5. Can anybody here suggest a good book or article on hormesis (I am guessing that the book Sean suggests deals mostly with exercise recovery)? This is fascinating stuff.

  6. Great discussion, Seth. I think it is clear that the research on the health effects of smoking is more complex than the simplistic “smoking is bad for your health”. From your references, it is reasonable to surmise a low dose hormetic benefit from light smoking. One other confounding variable is the type of tobacco; I’ve seen some claims that certain additives (including sugar) dramatically increase the carcinogencity of tobacco and that unadulterated “organic” tobacco is more benign — perhaps even beneficial at low dosages.
    Other complicating variables besides the tobacco dose and type include: frequency of smoking and individual differences (genetic, environmental, diet) that make individuals more or less susceptible to tobacco’s effects. And I really wonder about all the extreme linear extrapolations that have led to a global campaign against “second hand smoke”.

    You’ve raised great questions about the effects of smog as well. Based on what we see with other hormetic effects, however, I would think that constant, chronic smog would be deleterious, whereas occasional smog days alternating with clear days would be better. Perhaps a study could be done comparing health effects in cities with different smog patterns — you can’t just look at the average.

    All that said, I don’t smoke or spend much time in smoggy cities. And I don’t work for a tobacco company or polluting industry. I’m just interested in getting to the bottom of the science. That’s hard to do when virtually every “health” study is done within a politicized culture where the conclusions and recommendations are more important than the truth. And where we spend more effort banning smoking from bars than addressing serious health issues.


    BTW, I’m the “guy” that Thomas and Sean mentioned in their posts. I’m glad to see all the interest in hormesis!

  7. The smoking link seems to more yell at bad research than to truly convince that smoking is not bad. I have not reviewed the literature, but the authot admits his main point is to show misconduct rather than saying smoking not bad.

    Would be happy if soeone here truly studied the literature.

    The mixed data on passive smoking is another hint that smoking is not simpky bad bad bad linearly. I always wondered at this passive findings. Now i have a clue

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