Treated Poles
In Use
Installation
Toxic releases
to the general public and worker exposure. Since utility poles are
virtually everywhere, public exposure to them is widespread. Preservative
depletion while a pole is in service represents the most significant
release reported in the literature, although it is acknowledged that
there has not been adequate research. The main modes of chemical depletion
in poles are gravity migration, bio-, photo- and chemical degradation,
evaporation and leaching. Dermal exposure poses a significant risk
to utility workers who install and climb poles. Splinters from the
pole can also carry toxic materials directly into the bloodstream.
Workers who handled CCA-treated wood have been awarded compensation
by the courts.
Toxic chemicals
can seep out of poles, resulting in concentrations of highly contaminated
soil, or pooled liquid residue at the base of poles. Many of these
poles are in cities, parks, playgrounds and backyards. The bare
ground around a pole in a backyard may provide the pet cat's favorite
place to find loose soil. The pole may provide the backrest at the
baseball field for a child waiting for the next game. It may be
"base" for a game of tag.
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"A
United States Department of Agriculture employee who experienced
internal bleeding and vomiting followed by complete disability
after building picnic tables in an unventilated shop received
a total of $767,000 from CCA manufacutreres in 1987. Evidence
introduced during the trial included a memo from Koppers, Inc.
[a CCA manufacturer] indicating that they had reports of illness
from workers sawing treated wood as early as 1968. In 1990,
an employee of the Whatcom County (Washington) parks and Recreation
District whose nervous system was damaged during the installation
of bridges constructed of CCA-treated wood was awarded $450,000
in compensatory damages."49
From Journal of Pesticide Reform, 1991. |
Ecological
effects
The toxic chemicals
in treated poles seep out when poles are in place. The chemicals
can be carried into both surface and groundwater in concentrations
that can contaminate drinking water and impact the life of aquatic
organisms. Three poles treated with penta and located adjacent to
drinking water wells caused water contamination.
Retreatment
Retreatment processes and chemicals Treated wood poles have
a life expectancy of about 40 years, with considerable variability
depending on tree species, treatment method, and climate. Although
many utilities routinely replace poles as needed, many now conduct
inspections to identify poles that can be retreated and/or repaired.
Utilities companies
vary in their approaches to retreatment. A utility in Oregon reported
a ten-year retreatment cycle as preventive maintenance; a Washington
state utility conducts a periodic inspection and retreatment on
an as-needed basis. Other utilities have discontinued their inspection
and retreatment programs, in one case for budgetary reasons.
Retreatments
may be applied either externally or internally. External treatments
are used mostly with Southern or Ponderosa Pine and sometimes with
Douglas Fir and Lodgepole Pine treated with penta. They are applied
below the groundline using formulations of copper naphthenate (which
provides good surface protection but does not migrate very deeply
into the pole) and/or boron or sodium fluoride, which can penetrate
more deeply. Internal applications include:
- Void treatments,
in which an oil-based preservative such as copper naphthenate,
with or without an insecticide such as chlorpyrifos, is forced
into the pole through an inspection hole under pressure.
- Fumigation,
in which a volatile liquid or solid is placed into an inspection
hole, which is plugged. The fumigant--chloropicrin, methyl isothiocyanate,
and metam sodium (which decomposes to methyl isothiocyanate)--vaporizes
and moves through the wood.
- Water diffusible
systems, which use moisture in the pole to carry the active ingredient--sodium
octaborate tetrahydrate or copper naphthenate--through the pole.
Retreatment chemicals
expand the number of hazardous chemicals associated with the use of
chemically treated wood poles. Chloropicrin is an example of an extremely
toxic chemical used for tretreatment. (see
below) |
Chloropicrin:
A Deadly Retreatment Chemical
go back up Chloropicrin is extremely toxic.
The probable oral lethal dose in a human weighing 150 pounds
(70 kg) is 5-50 mg/kg, or between seven drops and one teaspoonful.
Chloropicrin may be fatal if inhaled, swallowed or absorbed
through the skin. Contact may cause burns to skin and eyes.
Runoff from fire control or dilution water may cause pollution.
It is not flammable. Very short exposure to this chemical could
cause death or major residual injury even though prompt medical
treatment is given.
EPA required
labeling includes the following precautionary statements:
Hazards to Humans and Domestic Animals; This pesticide
is toxic to fish and wildlife. Do not contaminate water by
cleaning equipment or disposal of wastes. Threshold concentrations
cause immediate burning of the eyes, spasmodic winking, tearing
and pain but no tissue damage. Permanent eye injury is unlikely
except following exposure to very high concentrations of chloracetopheonone.
Bronchospasm and laryngospasm may occur shortly following
exposure due to the irritant effects. Pulmonary edema may
be noted up to 12 to 24 hours after exposure. Can cause nausea,
vomiting, skin irritation. Hypersensitivity reactions have
been reported.
In the
atmosphere, chloropicrin will photodegrade with a half-life
of 20 days, forming phosgene and nitrosyl chloride. Chloropicrin
is washed out of the atmosphere by rain. If chloropicrin is
spilled, it will volatilize and leach into the groundwater
where its fate is unknown. In water it will volatilize (half-life
7.4 hours from a typical river) and photodegrade (half-life
3 days). It would not be expected to adsorb to sediment or
bioconcentrate in fish. Although its use as a fumigant, fungicide,
insecticide, tear gas and war chemical has a high potential
for exposure, no occupational or ambient air concentration
levels could be located. Chloropicrin is a contaminant in
drinking water of several U.S. cities which may result from
direct contamination of the water supply or from chlorination
of other contaminants.
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Number of Poles
in Use
The toxic trail
of wood utility poles runs from coast to coast. Below are tables which
show the concentration of utility "pole miles" by state and by the
service area of America's 100 largest utilities. Because every toxic
wood pole has been treated, and often times retreated, with highly
toxic wood preservatives, each of these poles serves as a mini-toxic
waste site. This means, in addition to the hundreds of EPA Superfunds
sits that are created as a result of producing these poles, using
a pole distribution formula explained below, there are well over 116
million mini-waste sites in backyards, school yards, along rivers
and lakes, and up and down roadsides across the country. Out of the
over 3,000 electric utilities in the U.S., over one-half of these
toxic poles are put in place by the 100 largest utilities. That translates
to more than one toxic pole per household.
The state of
Texas shows the highest number of poles with 395,752 pole miles
and over 11 million poles. West Virginia shows the least number
of poles with just under 89,000.
American Electric
Power, an investor-owned utility based in Columbus, Ohio has close
to 3.3 million utility poles in its service area. The second highest
concentration of poles is in California's Pacific Gas and Electric
Company service area. Their utility poles number almost 2.8 million.
Based on information
compiled from utility companies, and assuming a total of 135 million
utility poles nation-wide, there are 28.5 treated wood poles per
mile. This is based on a weighted average of 22 poles per mile in
REAs/PUDs (representing 41%of utilities). For the top 100 utilities
ranked by distribution of pole miles, there are an average of 32
poles per miles based on IOUs/MUNIS comprising 89% of the total
and REAs/PUDs comprising 11%.
Purchasers
of Utility Poles in the U.S.
| Type |
Number |
Total
Estimated Annual Purchase Volumes Mile |
%
Pole |
| IOUs |
198 |
3.100,000 |
44 |
| MUNIs |
1,818 |
1,450,000 |
15 |
| REA/PUDs |
997 |
2,280,000 |
41 |
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