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It would seem to me given the various warning about working with pressure treated wood (see Appendix 2) this section should not exist, but due to the fact that both of these items abound in our communities I shall address this serious concern.
David Stilwell has written four papers, that I am aware of, on this subject. You would be hard pressed to study this subject without crossing his name or the name of his research team partner, on his first study, Katja Gorny. The EPA has requested their studies and is presently reviewing these concerns. While most of Dr. Stilwells research published to date, has been well accepted, very little has been done about the problems of which he has made us aware. His four papers are included in the recommended reading section.
Here I quote from his paper, Arsenic in Pressure Treated Wood, "A controversy exists on the extent of arsenic exposure due to physical contact with CCA wood surfaces. Such surfaces include playground equipment, decks and picnic tables built using CCA treated wood. Studies have shown that virtually no inorganic arsenic is absorbed through the skin, but is readily taken up by ingestion. Thus the potential exposure is hand to mouth, and therefore, children are considered the most vulnerable to this potential risk." In his findings Dr. Stilwell recommends "consider the use of alternative products on areas that may be contacted by children."3
In a Report by the European Commission it states "Limited data on exposure
derived from dermal contact of children in playgrounds are considered. It is
concluded that, in a worse case scenario, the latter situation can result in
arsenic intake that alone can exceed the total TDI for children while even under
less extreme conditions it may make up a substantial proportion of the TDI.
It is therefore concluded that such exposure may constitute a health risk for
Surprisingly this conclusion is not carried through to the conclusions section of the Report. An attempt to downplay this risk by comparing it to the (unavoidable) risk from exposure to uncontaminated soil cannot be considered valid.
Finally, to the risks for children via dermal exposure, one could add here the risks of additional exposure via ingestion or inhalation of sand particles containing high concentrations of arsenic."7
The National Occupational Health and Safety Commission of the Commonwealth of Australia in a publication on the Uses of CCA treated wood says, "Where treated timber is to be used for playground equipment or log cabin construction, a storage period of four to six weeks is recommended before distribution. All treated timber intended for this use should also be washed prior to distribution to remove surface build-up of dried salts."5
In a excerpt from Spectrum Magazine we are told that, "the U.S.Product Safety Commission studied wood playground equipment and found that merely touching CCA treated wood can leave arsenic on the skin. Very young children can ingest up to 2,016 micrograms of arsenic per day from playing on treated wood if they put their hands in their mouth. The maximum safe amount of arsenic for a 25-pound child is 3.4 micrograms per day."13
In a health news bulletin put out by biolifeplus it states that "soil samples taken from a playground made from pressure treated wood showed an astounding 500 parts per million of arsenic. These levels are so high, that if a child ate just 2 tablespoons of contaminated dirt every day, it could prove fatal. Long term exposure to smaller amounts can cause nerve and blood vessel damage and several types of cancer among other things. Treated wood manufactures will insist that the wood is safe, but if you can obtain a product brochure from the company, you may be shocked to find out that this product has the potential to kill you."14
In an article in Kitchen Garden published in July 1998 we are told, "Far more important is the risk of potential transfer of arsenic to skin and mouths, particularly for children, whose small bodies don't tolerate arsenic as well as ours do. Chaney of the United Stated Department of Agriculture (USDA) points out that persistent leaching, however small, means that arsenic is continually coming to the surface of the wood, where it can easily be transferred to us or our children when we touch the wood. "There's just no way around it," Chaney says. "For me, this is the overriding decision not to use CCA."15
From an article published by Weather-Bos called, Wood Treatment Linked to Dangers, Samuel Rotenberg, a toxicologist at the EPA's Philadelphia regional office says, "As far as a boardwalk or deck built from CCA wood, I don't think that would present an unreasonable risk. But I would not build a children's sandbox out of the stuff because arsenic can leach into the sand and be eaten by the children. I also wouldn't build a sandbox under such a deck because we know now that there can be increased arsenic levels in those areas from sawdust produced during construction."2
In an issue of Environmental Building News published in January/February 1993 we read that, "Some playground manufacturers have begun substituting plastic for handrails and other surfaces where the danger of splinters is great. Picnic tables and park benches are an increasingly popular use for recycled plastic, particularily as this addresses the concerns about treated lumber and food."16
"Traces of the chemical salts can dissolve in water and then be transferred to the food by contact."17 This information comes from the Canada Plan Service (plan M-9401) Wood Preservatives.
In an article Kids at Risk, we read, "as the structure ages, the compounds may leach out into the dirt. In lower doses, according to numerous studies, CCA can impair intelligence and memory."18
In their article on pressure treated wood the Environmental News Network warns, " since chemicals may seep out, avoid using CCA wood on projects that will come in contact with food or water." Also they state, "Even the smallest amount of arsenic can kill a human being."19
On a fact sheet presented in a question and answer format from a maker of pressure treated wood we are on one hand told to wear gloves to avoid splinters when working with pressure treated wood and then we are told it is safe for picnic tables and playground equipment.20
In an evaluation of risk to children using arsenic treated playground equipment published by the Conrad Wood Preserving Co. in an article titled, Is Wolmanized wood safe around people, plants, and pets? We are giving the following conclusions:
On a fact sheet printed by the Connecticut Department of Health we are told, "the most toxic part of the CCA pesticide formulation is arsenic. Arsenic is a known human carcinogen, which can also be toxic to the skin and internal organs. These effects require long-term exposure and take years to develop. At high doses arsenic is an acute (immediate) poison that can cause death. However, the levels of exposure possible from arsenic in wood are too low to cause such acute effects. The major health concerns are that daily contact with arsenic leached from CCA treated wood might, under certain circumstances, lead to an increased risk for cancer or other long term health effects.
Recent studies have shown that rainwater leaches (releases) CCA from the treated wood. This can lead to contamination of soil beneath the wood structure. Also, a significant pesticide residue (fine coating) can be left on the wood's surface and picked up on hands or clothing. While the amount taken up depends on many factors, studies show that new boards and older boards both have significant amount of the arsenic on the surface. Given the widespread use of CCA-treated wood, it is possible for a child to be exposed to dislodgable arsenic at home, at the playground, and at school, making this an everyday kind of exposure for such children.
Young children (under six years of age) who play on CCA-treated decks or playscapes are expected to receive the greatest exposure to arsenic leached from wood. Children in this age category may play for extended periods on backyard or playground structures and they exhibit frequent hand-to-mouth activity. They are also most likely to play for periods of time underneath playscapes or decks.
Older children and adults who spend considerable time playing and working with CCA- treated structures may also receive significant exposures. Further, people who frequently eat on CCA-treated picnic tables that are not properly sealed may receive greater exposures."6
In CBS's Buyer Beware story on pressure treated we are told, "Arsenic doesn't disappear, that's the problem with these kinds of toxic heavy metals is it goes into the environment, you never get rid of arsenic you can just move it from place to place and the place I would like to keep it out of is the brains and tummies of people, especially young children."22
In the article Arsenic and Old Wood we read, "a decade ago, state officials in California became concerned that arsenic could rub off onto children climbing on playground equipment built of pressure- treated wood and required all new equipment at public playgrounds to be sealed every two years."1
David Stilwell's research23
shows clearly the importance of sealing pressure-treated wood to stop arsenic
leaching and is discussed under decks made from pressure treated wood. But I
will quote him here from an article in Weather-Bos, "If alternative materials
are available, why not use them and remove toxic materials away from children's
paths."2 In this
article Stilwell also questioned why the EPA requires warning stickers on CCA-treated
lumber, but not on products such as picnic tables or playground equipment manufactured
from the wood.
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