| 12. MTBE
Pollution
Back to: Start
Authors Opinion
Search
for Recent Information.
California's MTBE Review
There is
a balancing act between the need for fuel
quality and the overall environmental
impact of the auto-fuel system.
California wrestles with this balance and
decides to eliminate MTBE over time. But
other jurisdictions do not. Who is right?
We will see, or perhaps we will never
know!!
I
strongly suggest you attempt to assess
overall risk here. What, exactly, are we
guarding against here and what are the
costs? Can we balance the risks of MTBE
against all other risks? What is the
trisk of MTBE as compared to that of TEL?
I
recommend you look at Supreme Court
Justice Steven Breyer's book, "Breaking the Vicious Circle"
(Harvard University Press, 1993) for
indications of methodology for effective
risk regulation.
Justice
Breyer suggests that institutional
"tunnel vision" has the public
and its legislators chase down the last
standing concern, regardless of the
overall benefit. He suggests we do not
have as a nation, an overall risk
ordering that somehow compares the cost
of change as compared to its related
benefit.
|
|
|
|
The
State of California will require that MTBE be removed
from motor fuel by the end of 2002. This action,
initiated by Governor Gray Davis follows the
recommendations of a lengthy report prepared by the
University of California, Davis. I urge you to take the time to
read this report. You may well come to a differnt set of
conclusions than the author. This report makes the following
claims:
| 1.
That MTBE does NOT provide a significantly
beneficial effect in the emissions from
automobiles AS COMPARED TO OTHER REFORMULATED
GASOLINES. |
But the report de-emphasizes the
importance of the reformulated gasoline's AND the
difficulties of meeting the reformulated gasoline
requirements without MTBE. And it goes on
to deal at length with the potential toxicity of
the minor amounts of uncombusted tailpipe
effluents that do not, as their conclusions
indicate, adversely effect tailpipe emissions. |
| 2.
We find that humans can taste and smell MTBE at
below 1ppm (1 part per million)(1mg/ml) with some
people apparently able to detect the material at
as low as 1ppb (1 part per billion).
|
It is highly unusual that a material
should have this low a human detectable limit. Please note, the
detection limit has nothing whatsoever to do with
toxicity! |
| 3.
MTBE clears rapidly from the system - 1/2 life -
the time after which one half is gone - is one
hour. One major product that results from MTBE
metabolism is t-butyl alcohol, the 1/2 life of
TBA is about 12 hours.
|
MTBE if ingested is soon
gone. |
| 4.
Researchers try to find a relationship between
MTBE and cancer, asthma, neurotoxicity and
reproduction. They report anecdotal evidence of
neurotoxicity and asthma, can find nothing in the
way of reproductive problems in rodents but can
increase rat tumor rates by inhalation studies at
8,000ppm.
|
We will soon note the actual
concentrations we breathe or drink. |
| 5. Three-quarters of
Californias surface water reservoirs have no
detectable or less than 5ppb MTBE. About 10% are
above 14ppb. The California State standard is
35ppb maximum but will be reduced to 5ppb.
|
|
| 6. MTBE moves
along with underground water and perhaps 1% of .5
million water wells have a detectable MTBE
concentration as result of leakage of thousands
of California's underground storage tanks.
|
|
| 7. We will be
exposed to up to 5 micrograms/kg/day. That is
5ppb. Children may be exposed to 10% greater
amounts. |
The
rat studies above were done at more than 1
million times the concentration of exposure. The
report makes NO conclusions regarding the effect
of MTBE on humans. Further it does not cite the
lack of effect in animals at anywhere near the
concentrations of the human exposure. It calls
for more studies. |
| 8. Removal of
MTBE from gasoline is more cost effective than
remediation steps of cleaning air and water. All
costs anticipated are in the billiopns of dollars. |
|
| |
|
Matt Hermes
speaks:
This author believes the States
have the obligation to keep the MTBE level below what can
be detected by 99+% of people in the water supply. I
believe this must be done by vigorous action reducing
underground tank leakage. Tank failures present a far
greater hazard for their emission of hydrocarbons than
might be expected from the MTBE.
Other methods for the production
of reformulated fuels - replacement with ethanol, and
other materials will just generate new uncertainties.
Now, please look at
|
