In a previous blog I briefly mentioned the health and environmental harm that wooden telephones cause due to the creosote and other wood preserving chemicals that their makers routinely use to protect them from fungus, insects, woodpeckers and other living things. Here is some further information about these preservatives and their effects on humans and the environment.
The three major chemical wood preservatives are pentachlorophenol (penta), creosote, and arsenicals (copper chromium arsenate, or CCA). A fourth, copper naphthenate, is considered an alternative. The major wood preservatives, including pentachlorophenol (penta or PCP), creosote, and arsenicals, are ranked among the most potent cancer agents, promoters of birth defects and reproductive problems, and nervous system toxicants. They contain chemicals that in other contexts are labeled hazardous waste because of the dioxin, furans and hexachlorobenzene contaminants that are found in them. Penta is used to treat 45 percent of wood poles in the U.S. Treatment of utility poles represents 93 percent of the remaining uses of pentachlorophenol.After crossties, poles are the largest wood product still treated with creosote. Forty-two percent of wood poles are treated with inorganic arsenicals and 13 percent are treated with creosote.
As mentioned above the sole purpose of these chemicals is to preserve by killing living organisms. Because they easily move in air, water and soil, they threaten human life. In addition to causing both short- and long- term health effects -- from extreme irritation to nerve damage to spontaneous abortions to death, penta and creosote are linked to disruption of the endocrine system. This means that they can disrupt the basic messages of life, affecting fertility, reproduction and the
functioning of the nervous and immune systems and have been linked to breast
and prostate cancer.
Regarding environmental impacts, these chemicals contaminate the soil, leach into groundwater and move through the air. Because of these effects, in many contexts the use of these chemicals is severely restricted or banned in the U.S. except for their use on telephone poles. Twenty-six countries around the world have prohibited the use of penta. Furthermore the Province of Labrador in Canada has certain distance requirements (buffers) for chemically treated poles that are in proximity to water supply areas and the City of Seattle prohibits treated wood poles in wetlands and sees composite reinforced fiberglass poles as an alternative solution.
Chemically-treated poles are used in virtually every community in the U.S. Nearly 12 percent of all wood preservatives are used to treat utility poles. The rest is used on lumber and timber, plywood, fence posts, crossties and switch and bridge ties. In most cases, the poles, soaked in wood preservatives, are placed adjacent to property lines, or in backyards, front yards and playgrounds. The utility or telephone poles coated with a dark brown or oily substance --penta or creosote-- give off a petroleum odor. Other poles appear lighter, sometimes greenish, in color with no odor. These are treated with arsenicals. To maintain preservation of a pole over time, they are often pumped full of fresh chemicals, especially at the base where the wood meets the soil.
In addition to the environmental and health issues related to the use of wooden poles, they present a serious roadside hazard due to the large number of poles located in close proximity to the roadways and the unforgiving nature of existing pole designs. Vehicle collisions with utility poles result in nearly10 percent of all fixed-object fatal crashes annually (In 1999, there were 1,070 fatalities and approximately 60,000 injuries related to utility pole crashes. A new generation of utility pole designs employing energy absorbing composite materials can provide a
solution to lower the fatality and injury rates related to utility pole and car
Tests have shown the improved safety performance characteristics, of energy absorbing composite utility poles. They offer several inherent functional advantages over current timber poles including reduced weight, improved strength-to-weight ratio, ease of installation, low maintenance, and environmental friendliness.