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Re: Deaths from fossil fuel burning air pollution
Automobile and truck exhaust contain mostly CO by weight, NO, NO2, some
hydrocarbon emissions. Diesel exhaust contains fine particles but gasoline
engine exhaust doesn't have a significant amount of particulate matter.
Crustal dust and agricultural dust do contain 10-micron particles (and some
smaller) and since 10-micron is usually considered respirable (inhaled into
the lung alveoli) I have never understood how one can distinguish
epidemiologically between 10-micron and 2.5-micron particles, EPA
notwithstanding. Aluminum smelters produce mostly fluoride emissions.
Copper smelters produce a lot more sulfur dioxide than power plants
(unregulated, a pound of SO2 per pound of copper) and the particulate
constituents are quite different from those of fossil fuel plants
(especially in metal content). coke ovens produce CO and hydrocarbons, as
well as very fine carbon particles. Gas-fired fossil fuel plants produce
almost no particulate matter and emit mainly NO and NO2. Kraft-process pulp
mills produce emit hydrogen sulfide.
In most urbanized areas, the most prevalent pollutant by weight is CO. In
places like Los Angeles and Denver, it is photochemical smog formed by the
photochemical reaction of hydrocarbon vapors and NO. In Tacoma, WA, it was
SO2 and arsenic particles from the smelter until the smelter was shut down.
In Kellogg, ID, it was lead from the lead smelter.
Depending on where one lives, the pollutants one inhales can be very
different. This is why I do not find the results of the cited studies very
credible. Moreover, health effects of the common air pollutants (like SO2,
with and without particulate matter) are generally observed in individuals
only at much higher concentrations than are present in ambient air, even
polluted air, and we are not talking about death here, but about stimulating
a cough reflex or producing an unpleasant or sickening odor. One gets back
to the problem that isolating the effect of one constituent of polluted
ambient air is extraordinarily difficult.
None of this is meant to be a defense of polluting the air, and I believe
that is pretty clear. I am just disturbed that the projection of "air
pollution deaths" uses the same simplistic notions that we object to in
projecting cancer deaths from exposure to ionizing radiation. Air pollution
is unpleasant, various pollutants enhance allergic reactions and respiratory
problems and make your eyes sting, persistent odors can make you sick, and
all of this is and has been quite enough for the U. S. to have embarked on a
major cleanup of the air in 1970 that continues today, and has, in fact,
been quite effective. Nuclear power is a perfectly good way to produce
electricity, and its dangers and health effects are greatly overstated.
However, burning fossil fuels and controlling the emissions of the plants is
also an acceptable electrical production method, and I do not think much is
gained in the argument by overstating its dangers and health effects.
(No I don't have stock in any utility no matter what kind of fuel it uses,
and I am not and have never been employed by any industry associated with
fossil fuel power generation. Quite the contrary.)
Ruth Weiner
ruth_weiner@msn.com
-----Original Message-----
From: Bernard L Cohen <blc+@pitt.edu>
To: Multiple recipients of list <radsafe@romulus.ehs.uiuc.edu>
Date: Wednesday, November 29, 2000 10:02 AM
Subject: Re: Deaths from fossil fuel burning air pollution
>
>On Wed, 29 Nov 2000, ruth_weiner wrote:
>
>> Re: definition of air pollution: I was responding to the question of how
air
>> pollution is defined, and I responded with a rather standard legislative
and
>> textbook definition, namely (briefly) that a pollutant is something not
>> found in "clean air," or not found in high concentrations therein. It
makes
>> no sense for each of us to make up our own definition. There are
certainly
>> sources of air pollutants in addition to fossil fuel burning power plants
>> (and indeed, natural gas plants emit fewer and different pollutants than
>> coal plants -- no particulates, for example). Automobile and truck
exhaust,
>> all kinds of smelters, coke ovens, agricultural and road dust, crop
>> spraying, chemical plants are just a few. One source used by Pope, et al,
>> is, I believe, a steel plant and not a power plant.
>
> --I meant the definition for purposes of my message. The people
>who do these studies have concluded that fine particulate (<2.5 microns)
>is a suitable surrogate for fossil fuel burning pollution. There is a long
>history of how this was decided on, and I am not enough of an expert to
>defend it here. I believe agricultural and road dust particles are coarser
>than 2.5 microns.Most of the other things you mention are from fossil fuel
>burning.
>
>>
>> Re reference to the LNT: a linear conversion factor implies a linear
>> dose-response relationship, does it not? The objections to applying a
>> linear conversion factor in the case of radiation health effects are, in
>> part, that it involves an extrapolation outside of the data, but data on
>> health effects from large doses of ionizing radiation certainly exist
(e.g.,
>> the radium dial painters study). The citation of the large number of
>> "deaths" or "premature deaths" postulated in the air pollution case also
>> involves extrapolation and a linear conversion factor.
>
> --There is a huge difference. For radiation, there are no data on
>effects below 20 rem, but people use it for much lower levels, truly an
>extrapolation. For air pollution there are lots of data points throughout
>the region where it is used, so there is no extrapolation involved
>
>
>> Finally, to reiterate: years of life lost would appear to be a much
better
>> metric than death, or even premature death. Controlling the confounding
>> factors in putative deaths from inhaling air pollutants is
extraordinarily
>> difficult, if not impossible.
>
> --EPA and others do estimate the loss of life expectancy for
>victims of air pollution - I have been using 7 years - and this allows a
>quantitative comparison with nuclear victims for whom loss of life
>expectancy averages about 16 years. Dozens of investigators have faced the
>problem of controlling for confounding factors so this issue has been
>worked over extensively. The early work on this was done by Lave and
>Seskin and they wrote a book on the subject.
>
> --Granted that there are difficult problems, does that mean that
>we should ignore the health effects of air pollution? That is the game
>played by the anti-nukes. They say that nuclear power can kill people (<10
>per year treated probabilistically, even with LNT), whereas they ignore
>the 10,000 or so deaths per year from the competing source of
>electricity, air pollution from coal burning. Basically, that is the case
>for nuclear power if public health is the issue.
> How do you respond to the fears that nuclear power can kill
>people?
>
>
> >
>> >
>> >On Tue, 28 Nov 2000, ruth_weiner wrote:
>> >>
>> >> This type of conversion factor is now being applied to inhaled air
>> >> pollutants (and this is in fact an application of the LNT theory),
which
>> is
>> >> quite a stretch, and which I myself do not agree with.
>> >>
>> >> An air pollutant is defined in a number of laws and regulations as a
>> >> substance other than nitrogen, oxygen, carbon dioxide, water vapor,
>> ozone,
>> >> and argon, or a significant quantities of a substance like CO and
some
>> >> terpenes that may in very small quantities be constituents of clean
air.
>> >> Particulate matter is a pollutant whether it comes from a stack, is
>> crustal
>> >> dust, or comes from a volcanoic eruption.
>> >
>> > --Here I define air pollution as things emitted from fossil fuel
>> >burning, with very fine particulate (<1.5 miicron) serving as a
surrogate.
>> >How do you explain the fact that there is a statistically robust
tendency
>> >for areas with high air pollution to have higher mortality rates than
>> >areas with low air pollution, after considering other factors that may
be
>> >relevant? No linear-no threshold assumption is involved; these are
>> >straightforward data. Also, how do you explain the fact that in a given
>> >city, mortality rates are higher when pollution is higher? Dozens of
>> >studies have corroborated these findings.
>> >
>> >
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>>
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>
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