Poison Poles — A Report About Their Toxic Trail and Safer Alternatives The Toxic Trail


Treated Poles In Use


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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.

"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 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.

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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