The Consumer Product Safety Commission scared parents this week about wood playground equipment causing cancer in children. It’s another case of a make-believe health risk leading to very real costs for consumers.

A new CPSC report claims some children may face an increased risk of lung or bladder cancer over their lifetimes from playing on playground equipment made from chromated copper arsenate (CCA) pressure-treated wood. Supposedly, arsenic residue from the treated wood gets on kids’ hands and hands go into mouths.

CCA is a chemical preservative that protects wood from rotting and that has been used to pressure treat lumber used for decks, playsets and other outdoor uses since the 1930s.

CPSC estimated the increased cancer risk to range from two cases in every million people to 100 in a million.

For comparison, about one out of every 10,000 nonsmokers (0.01 percent) gets lung cancer. So based on CPSC estimates, playing on CCA-treated playground equipment might increase someone’s lifetime lung cancer risk from a baseline lifetime risk of 0.01 percent to between 0.0102 to 0.020 percent.

Based on CPSC estimates, playing on CCA-treated playground equipment might increase lifetime bladder cancer risk for men from about 2 percent to between 2.0002 to 2.010 percent. For women the hypothetical risk increases from about 0.5 percent to between 0.5002 and 0.510 percent.

Even if CPSC’s cancer risk guess-timates are true, these obviously aren’t meaningful increases in risk. But is it even reasonable to believe that CCA-treated wood is a cancer risk in the first place?


First, there is not the slightest evidence that any child has ever developed cancer from CCA-treated wood.

Next, studies don’t show that wood treatment plant workers and carpenters -- who have relatively higher exposures to CCA -- have increased health risks.

So what’s the reason for the CCA scare?

CCA contains arsenic, a substance the Environmental Protection Agency considers as “known” to cause cancer in humans. The EPA’s opinion is based on studies reporting that some human populations exposed to relatively high levels of arsenic in drinking water -- in Taiwan, for example -- experienced higher (not high) rates of various cancers.

The EPA and, apparently, CPSC assume that because high exposures to arsenic in drinking water -- on the order of 2000 micrograms (millionths of a gram) per day and greater -- might slightly increase cancer risk in some people, then any exposure to arsenic increases cancer risk in everyone.

This assumption, however, is not supported by studies that do not show increased cancer risk among populations with lower levels of arsenic exposure from drinking water.

Moreover, children are exposed only to trace levels of arsenic through playground equipment -- about 3.5 micrograms (millionths of a gram) per day, according to the CPSC. This level is more than 570 times lower than the level claimed by the EPA to increase cancer risk slightly from arsenic in drinking water.

More compelling evidence that arsenic in CCA-treated wood is not a health threat to children was pointed out by the Florida Physicians Arsenic Workgroup in a June 2002 letter to the Florida Department of Health.

Noting that arsenic is known to cause skin diseases, the Workgroup wrote, “CCA-treated wood has never been linked to skin diseases or cancer in children exposed during recreational use. Manifestations of arsenical skin diseases and cancers would be expected after 30-plus years of use if toxic levels of arsenic were leaching from the wood.”

That is, if children were exposed to harmful levels arsenic, there should at least be reports of skin disease related to arsenic. But there aren’t.

How did the CPSC get tangled up in the pressure-treated wood jungle gym?

Anti-chemical activists at the Environmental Working Group petitioned the CPSC to ban the use of CCA pressure-treated wood in 2001.

The Bush administration’s CPSC -- unwilling to be pilloried as the Bush EPA was by the arsenic-in-drinking water controversy in 2001 -- apparently is inclined to cave on the CCA controversy for fear of more bad publicity on arsenic. Still, the agency says it will defer final action on CCA pressure-treat wood matter until next month.

In the meantime, the CPSC is hoping the EPA can bully CCA manufacturers into phasing out CCA treatment of wood for most consumer uses by the end of 2003. That way, the CPSC can dispose of the controversy without imposing a ban -- that is, painlessly.

For consumers, however, there is no bright side. Prices for wood pressure-treated with a CCA substitute are estimated to increase by 20 to 25 percent.

You won’t be any safer -- just poorer.

Steven Milloy is the publisher of JunkScience.com, an adjunct scholar at the Cato Institute and the author of Junk Science Judo: Self-defense Against Health Scares and Scams (Cato Institute, 2001).

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