can cause cancer
of Human Exposure to CCA-Treated Timber
can cause cancer
chromium and arsenic are all heavy metals which means that they
are metallic chemical elements that have a high density and are
toxic to humans at very low concentrations. Arsenic is of most concern
in this context because there is evidence from several published
scientific studies (see for example Children's
Health section) that the arsenic leaches out of CCA-treated
wood over time.
to the World Health Organisation (cited in Sharp and Walker, 2001:
2) and the US Environmental Protection Agency (Office of Pesticide
Programs, 2002b) arsenic is “a known carcinogen and is acutely
toxic”. It can cause various cancers including lung, bladder
and skin cancer, as well as non-cancer damage, including reproductive
and neurological problems (CPSC, 2003b: 14). People can be exposed
through touching the timber as surface arsenic sticks to human skin
(Gray and Houlihan, 2002: 9). It can be absorbed by the skin (less
likely), breathed in with wood dust particles, or transferred to
the mouth, for example by subsequent handling of food (CPSC, 2003b:
of Human Exposure to CCA-Treated Timber
cutting, drilling etc
Adapted from (Standards Australia, 2003: 7)
a wide range of research from international sources documenting
the effects of cumulative exposure to arsenic:
US Consumer Product Safety Commission (CPSC, 2003a) cites studies
showing high levels of arsenic in drinking water are linked with
increased incidence of lung and bladder tumours in Taiwan.
et al (2003) report that in rats exposed to CCA, arsenic
was detected in lung, liver, heart and the viscera, and copper
was detected in the liver.
on toenail clippings by Beane Freeman et al (2004) found
an increased risk of melanoma for participants with arsenic exposure,
measured through toenail arsenic concentrations. The majority
of participants who reported they had been exposed to arsenic
on the job had the highest arsenic levels of all participants,
“indicating that occupational exposure may be an important
source of arsenic contamination”.
et al (2001) found that, at extremely low levels of exposure,
arsenic is found to alter hormonal function in the 'glucocorticoid'
system, which influences physiological processes, such as growth
control, glucose regulation and protein metabolism.
there is not enough epidemiological evidence to ensure agreement
about the health impacts of CCA exposure. This is explained by Belluck
et al (2003) as due to:
not being trained to recognize soil arsenic exposures;
- No mandatory
surveillance and reporting system (or tabulation of data) for
soil-induced health impacts;
effects (eg dermal, cerebrovascular and cerebral effects) being
attributed to other causes;
health effects from exposure not being observed until the damage
is advanced; and
being associated with more than thirty different health effects.
are aware that correlating health impacts with soil-related arsenic
exposures in highly mobile populations is very difficult, but reiterate
that there is not sufficient data to rule out elevated surface soils
levels of arsenic as a cause of human morbidity or mortality (Belluck
et al, 2003).
is exacerbated by the fact that during the decades that timber has
been treated with CCA, there has been no real effort collate the
long term health records of people working in the industry. The
Australian Pesticides and Veterinary Medicines Authority (APVMA)
is only now belatedly recommending that health data be kept by the
uncertainty is whether the CCA components (copper, chromium and
arsenate) in combination differ from effects caused by an exposure
to each metal separately. For example, the presence of chromium
and copper may alter the health impacts of the arsenic, such as
absorption, retention and excretion (US EPA, 2003). Also some people
are more sensitive to chemicals than others (Buckland, 2005).
Freeman, L., Dennis, L., Lynch, C., Thorne, P. and Just, C. (2004),
‘Toenail Arsenic Content and Cutaneous Melanoma in Iowa’,
American Journal of Epidemiology, 160(7):679-687.
D., Benjamin, S., Baveye, P., Sampson, J., and Johnson, B. (2003),
‘Widespread Arsenic Contamination of Soils in Residential
Areas and Public Spaces: An Emerging Regulatory or Medical Crisis?’,
International Journal of Toxicology, 22, pp. 109-128.
D. (2005), ‘Global Recognition Campaign
for Multiple Chemical Sensitivity’,
(2003a), Fact Sheet: Chromated Copper Arsenate (CCA) -Treated
Wood Used in Playground Equipment, U.S. Consumer Product
Safety Commission, February 7, http://www.cpsc.gov,
(2003b), Briefing Package: Petition to Ban Chromated Copper
Arsenate (CCA)-Treated Wood in Playground Equipment (Petititon
Hp 01-3). Washington, DC: US Consumer Product Safety Commission
S. and Houlihan, J. (2002), All Hands on Deck, Washington,
D.C.: Environmental Working Group (EWG). August. http://www.ewg.org/reports/allhandsondeck
R., Davis, A., Lariviere, J-P, and Hamilton, J. (2001), ‘Arsenic
Alters the Function of the Glucocorticoid Receptor as a Transcription
Factor’, Environmental Health Perspectives, 109: 245-251.
D-H, Son, D-W, Lee, M, and Kang, C (2003), ‘Biological Safety
Evaluation Of Animal Contact Of Preservative-Treated Wood’,
International Research Group, 34th Annual Meeting, Brisbane, Australia,
of Pesticide Programs (2002b). ‘Questions & Answers:
What You Need to Know About Wood Pressure Treated with Chromated
Copper Arsenate (CCA).’ US Environmental Protection Agency
(EPA). 12 February. http://www.epa.gov/oppad001/reregistration/cca/cca_qa.htm.
R. and Walker, B. (2001), Poisoned Playgrounds: Arsenic in
'Pressure-Treated' Wood, Environmental Working Group and
Healthy Building Network, Washington D.C. http://www.ewg.org/reports/poisonedplaygrounds
Australia (2003), ‘DR03476-03481: Draft for Public Comment’.
EPA (2003), ‘Effects Of Metal-Metal Interactions On Toxicokinetics
Of Arsenic From CCA-contaminated Materials And Environmental Media
(Soil, Dislodgeable Material)’, A Probabilistic Risk Assessment
For Children Who Contact CCA-Treated Playsets And Decks, Draft
Preliminary Report, November 10,Pp 297—298.