Environmental Engineering Reference
In-Depth Information
fracking. If Fox had opposed drilling, he wouldn't have gotten very far, because the public knows that,
while accidents can happen while drilling, drilling itself is a vital human activity.
A more sophisticated version of false attribution uses prestigious studies based on speculative models.
Justasclimate discussionstodayaregovernedbyspeculative modelswhose(in)validityisrarelyspecified,
so are pollution discussions. Regulators often use models that assert unprovable relationships between tiny
amounts of particulate emissions and health problems.
The evidence is brought to us via “studies,” cited by news media eager to run dramatic, “if it bleeds it
leads” headlines. The main thing to watch out for here is a statement like “X causes Y”—e.g., “coal causes
asthma.” That's usually an oversimplification at best; often it's completely bogus. It's hard to prove cause
and effect. Here's a good question to ask when you encounter these kinds of claims: “Could you explain
how you prove that—how you know that coal
in particular
caused asthma instead of everything else that
might have caused it?” Usually the answer is no.
Let's look briefly at the claim that coal causes asthma problems through power plants' emission of par-
ticulate matter (PM).
triggered a variety of theories about the causes.
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Claims about decreasing air quality or increasing expos-
ure to toxins do not stand up,
as the increase in prevalence seems to be strongest in countries with much
improved environmental quality;
for example, wealthier, cleaner West Germany had more asthma prob-
lems than poorer, dirtier East Germany.
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To put it in reverse,
countries with higher pollution levels have systematically shown lower rates of
chronic respiratory diseases like asthma.
Something like asthma is a complex issue, and to use it to attack
coal is to attack the health of everyone.
Or take mercury. Here's a summary of the typical argument about coal and mercury: Coal naturally
contains mercury, a neurotoxin that can damage the nervous system, the brain, and other organs. When we
burn coal, that mercury gets released into the atmosphere and ultimately rains down into bodies of water.
This leads to higher mercury levels in fish, which lead to higher mercury levels in our bodies when we
eat fish. Those levels are dangerous, particularly to the fetuses of pregnant women, whose children can
experience developmental problems and learning disabilities. Therefore, coal is a massive threat to public
health.
But here's the full context.
Mercury, a metal element, exists naturally throughout the world, most notably in the oceans, which con-
tain an estimated 40 million to 200 million tons of mercury, as well as in most forms of plant and animal
life. Mercury is released into the air by volcanoes, wildfires, and in far lesser quantities, the burning of
coal. Natural causes of mercury are why the region of the United States with the highest mercury levels is
the Southwest, whereas there are much lower levels in coal-heavy West Virginia and Kentucky.
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Mercury, like any substance, is toxic in certain forms and doses and harmless in others. The form of
mercury that is of particular concern to human health is called methylmercury (or monomethylmercury),
a combination of mercury, carbon, and hydrogen. Discussions of “mercury poisoning” are misleading, be-
causemercurybecomesmethylmercuryonlyundercertainconditions,andmethylmercurycanbeabsorbed
by human beings in relevant quantities only under certain conditions (for example, the element selenium
seems to prevent the absorption of methylmercury).
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To be sure, negative cause-and-effect relationships do exist between fossil fuel emissions and human
health—in certain concentrations and in certain contexts—but this doesn't appear to be one of them.
Which brings us to the no-threshold fallacy.
