EWG's Comments on CCA Ban Petition HP01-3

Testimony before the Consumer Product Safety Commission

Jane Houlihan
Vice President for Research
Environmental Working Group
Washington DC

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March 17, 2003

I appreciate the extended time and the opportunity to present our viewpoints here.

My name is Jane Houlihan, and I am the Vice President for Research at the Environmental Working Group. EWG is a non-profit environmental research and advocacy organization with offices in Washington DC and Oakland, California. We are entirely foundation funded, we have no members, and we accept no industry or government money.

In May 2001 the Environmental Working Group and Healthy Building Network petitioned the Consumer Product Safety Commission to ban the use of CCA-treated wood in playground equipment, because the research available at the time showed that arsenic was a potent carcinogen, that arsenic is present at significant concentrations on CCA-treated wood and in underlying soil, and that the health risks posed by this wood are greater than previously recognized.

Since we submitted our petition, new studies show that children who regularly contact CCA-treated wood face an even greater cancer risk than previously believed. These important studies were not used by CPSC in developing the risk estimates before you today. In light of this new information, we believe CPSC has substantially underestimated the cancer risk associated with CCA-treated wood.

Given the magnitude of risk, we disagree with CPSC's recommendation to defer action on this petition. Using authority under the Federal Hazardous Substances Act, we recommend that CPSC immediately ban the use of CCA-treated wood in new playsets, a use that EPA estimates could continue for at least another year unless CPSC acts. We also recommend that CPSC immediately recall playsets on public playgrounds, and that using their authority under the Consumer Product Safety Act, Section 15(d)(3), CPSC require the treated wood industry to directly refund consumers who have purchased CCA-treated wood playsets.

These data show that CPSC has severely underestimated risk to some children, by not considering in their assessment the wide range of residue levels found on various structures. The data also point to the importance of CPSC giving the public comprehensive recommendations on mitigating risk from existing wood structures, including frequent sealing.

Conclusion and Recommendations. CCA in existing play structures is a public health problem very similar in magnitude and certainty to lead paint. Both present significant health risks that last long after regulatory action banning their sale and use. Both have been found to pose a greater health risk than believed when they were first sold. Both disproportionately affect children. In each case the regulated industries fought remedial action after the ban, and in each case, failing to take this remedial action would have very nearly completely undermined the effectiveness of the ban. Imagine the unnecessary harm to children that would have occurred had their been no remedial action to reduce lead exposures after the ban on lead in paint. The same level of harm will result from a failure on the part of commissioners to force remedial action to recall CCA-treated play structures on playgrounds.

We recommend that:


California Environmental Protection Agency. 2003. Public Health Goal for Arsenic in Drinking Water. Draft. March 2003. Available online at http://www.oehha.ca.gov/public_info/press/AsPress.html

Consumer Product Safety Commission. 2003. Briefing Package. Petition to ban chromated copper arsenate (CCA)-treated wood in playground equipment (Petition HP 01-3). February 2003.

Environmental Protection Agency (EPA). 2003. Supplemental Guidance for Assessing Cancer Susceptibility from Early-Life Exposure to Carcinogens (External Review Draft). USEPA EPA/630/R-03/003. 28 Feb 2003. U.S. Environmental Protection Agency. Risk Assessment Forum, Washington, DC, 86 p. Available online at http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=55446.

Tulve NS, JC Suggs, T McCurdy, EA Cohen Hubal, J Moya. 2002. Frequency of mouthing behavior in young children. Journal of Exposure Analysis and Environmental Epidemiology. 12, 259-264.

Waalkes MP, JM Ward, J Liu, BA Diwan. 2003. Transplacental carcinogenicity of inorganic arsenic in the drinking water: induction of hepatic, ovarian, pulmonary, and adrenal tumors in mice. Toxicology and Applied Pharmacology. 186, 7-17.


Attachment A. EWG's Sampling Instructions, Home Testing Kit for Arsenic Treated Wood.

Attachment B. Waalkes MP, JM Ward, J Liu, BA Diwan. 2003. Transplacental carcinogenicity of inorganic arsenic in the drinking water: induction of hepatic, ovarian, pulmonary, and adrenal tumors in mice. Toxicology and Applied Pharmacology. 186, 7-17.

Attachment C. Tulve NS, JC Suggs, T McCurdy, EA Cohen Hubal, J Moya. 2002. Frequency of mouthing behavior in young children. Journal of Exposure Analysis and Environmental Epidemiology. 12, 259-264.

Attachment D. Model Methodology. Cancer Risks from Children's Exposures to Arsenic-Treated Wood: Methodology for Monte Carlo Style Risk Analysis

  1. EPA's New Assessment of Enhanced Potency of Carcinogens in Early Life. On March 3 2003 the EPA released cancer risk assessment guidelines showing that carcinogens are more potent in early life exposures. Through its review of 23 peer-reviewed studies of cancer incidence from the past 50 years, EPA has determined that infants up to age two are, on average, ten times more vulnerable to carcinogenic chemicals than adults, and for some cancer-causing agents are up to 65 times more vulnerable. The Agency also found that children from age two to 15 are three times more vulnerable to carcinogens than adults.

    In developing these potency factors the Agency cites as key evidence a new National Cancer Institute study of cancer incidence from early life exposures to arsenic in lab animals (Waalkes et al. 2003). Under its new guidelines, the Agency will require its staff to incorporate these potency factors when assessing early life exposures to chemicals that cause genetic damage. These factors are not safety or uncertainty factors, rather they are based on a review of the literature that showed that 82% of mutagens were more carcinogenic when exposure occurred earlier in life and the median increased potency of mutagens was 10. CPSC has not taken this new information into account in its risk assessment, resulting in an underestimate of risk by a factor of about four.

  2. National Cancer Institute study shows early life susceptibility cancers caused by arsenic, and supports a linear model for cancer risk. A 2003 study conducted by the National Cancer Institute and National Institute of Environmental Health Sciences (NCI-NIEHS) found that a brief 10-day drinking water exposure to arsenic in utero at 42.5 and 85 parts per million (ppm) caused dramatic increases of malignant, benign and precancerous lesions at multiple sites in the mice in later life. Tumors sites included the lung, liver, adrenal gland and ovary. In addition, arsenic caused proliferative lesions to develop in the uterus and oviduct. Some of the tumor sites, such as lung and liver, overlap with known human arsenic target organs. Moreover, arsenic significantly increased the incidence of developing any type of tumor, including malignant tumors, which is also consistent with the human epidemiology findings.

    Waalkes et al. suggest that arsenic is acting at the first stage of carcinogenesis as a tumor initiator, or mutagen, because arsenic dramatically increased tumor incidence at multiple sites following a 10-day exposure early in life. The short-term exposure argues against arsenic acting as a tumor promoter, which generally requires long-term exposure and shows reversibility of action when exposure stops. The early in life exposure argues against arsenic acting as a tumor progressor because tumor progressors typically act on cells that have already been neoplastically transformed, and progression, as a stage of carcinogenesis, is typically associated with concurrent existence of benign or malignant neoplasms. In summary, this new study supports prior decisions by various government agencies to assume that arsenic's mechanism of carcinogenicity produces a linear response.

  3. New data show high and persistent arsenic residue levels on hundreds of wood structures. Since November 2001, consumers across the country have tested 598 playsets, picnic tables, decks, and treehouses across the country, and in some cases the arsenic-contaminated soil beneath them, through an at-cost testing kit sold through EWG's website, www.ewg.org. The samples are analyzed by the University of North Carolina - Asheville's Environmental Quality Institute. The sampling method is analogous to methods used by various government agencies in conducting residue sampling, and is included in this testimony as Attachment A. The results of the consumer testing program show:

    • Arsenic residue levels on 295 playsets ranged from 0 to 960 micrograms on an area the size of a four-year-old's handprint (100 cm2), with a median value of 8.3 ug/100cm2.

    • Arsenic residue levels on 598 wood structures, including playsets, picnic tables, decks, and treehouses ranged from 0 to 2813 ug/100cm2, with a median value of 9.0 ug/100cm2. On ten structures the residue level exceeded 500 ug/100cm2.

    • Older decks and playsets (seven to 15 years old) expose people to just as much arsenic on the wood surface as newer structures (less than one year old). The amount of arsenic that testers wiped off a small area of wood about the size of a four-year-old's handprint (100 square centimeters) typically far exceeds what EPA allows in a glass of water under the Safe Drinking Water Act standard (EWG 2002).

    • Commercial deck sealants provide no long-term reduction in arsenic levels on the surface of arsenic-treated wood. Sealants appear to reduce arsenic levels for about six months, but surface arsenic levels on wood sealed more than six months ago are statistically indistinguishable from levels on wood that has never been sealed. Just after application, sealants begin to wear off through physical abrasion and weathering. The highest arsenic level measured from 300 samples, 1053 micrograms on a 100 cm2 wood surface, was found on a Houston, Texas structure sealed two years prior to testing.

    • New study from EPA shows children put their hands in their mouths far more often than previously believed. Scientists from EPA's National Exposure Research Laboratory compiled statistics on detailed observations of mouthing behavior among more than 300 children, and found that children put their hands in their mouths at nearly twice the rate previously believed - on average 16 times per hour for children over 2 years old, and 18 times per hour for children less than 2 years old. The study recorded hand-to-mouth behavior a maximum of 48 times per hour. Also of note in this study are two frequent behaviors that could dominate risk but are not included in CPSC's risk assessment: mouthing of playset surfaces (mean of 4 to 7 times an hour for the children studied), and mouthing of toys stored beneath playsets (such as sandbox toys), a behavior observed on average between 42 and 56 times an hour. This study is included as Attachment C.

    • New risk assessment from California shows the average residue on a hand-sized area of CCA-treated wood structure is 2000 times higher than safe levels (defined as a 1 in 1,000,000 cancer risk). On March 7 2003, California's branch of the EPA released new arsenic risk assessments that show a dramatically lower "safe" level for arsenic in drinking water than US EPA's new standard, setting their public health goal for arsenic at 0.004 micrograms per day (4 parts per trillion in water), 2500 times lower than EPA's new standard of 10 parts per billion, and 2000 times the average arsenic residue level on 100 cm2 of wood. California's risk assessment adds to the growing number of public health agencies that have confirmed the cancer-causing potential of very low doses of arsenic.

    • Risk assessment incorporating new findings shows average excess lifetime cancer risk of 1 in 500 for children who play on CCA-treated wood three times a week. In 2001 EWG constructed a risk assessment model incorporating Monte Carlo techniques that account for variability in arsenic residue levels, behavior patterns, and size of a child, and that compute the spectrum of risk across the population. We presented this model to the EPA's Scientific Advisory Panel in October 2001. The Panel recommended that EPA adopt this modeling technique in their assessment of risk from CCA wood, and the Agency is moving forward with a Monte Carlo style assessment. EWG's model methodology is attached as Attachment D. When we incorporate findings from the new studies described above, the model shows:

      • One in 500 children who play on CCA-treated playsets three times a week are expected to develop cancer from these exposures.

      • Ten percent of children who regularly play on CCA-treated playsets face an excess lifetime cancer risk greater than one in 100.

      • CPSC immediately ban the use of CCA-treated wood for new playsets.

      • CPSC immediately recall all play structures on public playgrounds, because these facilities clearly present the greatest long-term risk to children because of their long life and heavy use.

      • Using authority under the Consumer Product Safety Act, Section 15(d)(3), CPSC require the treated wood industry to directly refund consumers who have purchased CCA-treated wood playsets.

      • CPSC work with EPA to expedite studies of the effectiveness of sealants, and launch an aggressive consumer education campaign designed to teach people how to mitigate risk from CCA-treated playsets and other structures.

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