Lead speciation in indoor dust: a case study to assess old paint contribution in a Canadian urban house
Residents in older homes may experience increased lead (Pb) exposures due to release of lead from interior paints manufactured in past decades, especially pre-1960s. The objective of the study was to determine the speciation of Pb in settled dust from an urban home built during WWII. X-ray absorption near-edge structure (XANES) and micro-X-ray diffraction (XRD) analyses were performed on samples of paint (380–2,920 mg Pb kg−1) and dust (200–1,000 mg Pb kg−1) collected prior to renovation. All dust samples exhibited a Pb XANES signature similar to that of Pb found in paint. Bulk XANES and micro-XRD identified Pb species commonly found as white paint pigments (Pb oxide, Pb sulfate, and Pb carbonate) as well as rutile, a titanium-based pigment, in the <150 μm house dust samples. In the dust fraction <36 μm, half of the Pb was associated with the Fe-oxyhydroxides, suggesting additional contribution of outdoor sources to Pb in the finer dust. These results confirm that old paints still contribute to Pb in the settled dust for this 65-year-old home. The Pb speciation also provided a clearer understanding of the Pb bioaccessibility: Pb carbonate > Pb oxide > Pb sulfate. This study underscores the importance of taking precautions to minimize exposures to Pb in house dust, especially in homes where old paint is exposed due to renovations or deterioration of painted surfaces.
KeywordsIndoor dust Lead speciation Old paint X-ray absorption near-edge structure spectroscopy Pb XANES
- APac Chemical Corporation. (2002). Citric acid. General product information. http://www.apacchemical.com/citricacidprint.htm. Verified 16 December 2009.
- Butte, W., & Heinzow, B. (2002). Pollutants in house dust as indicators of indoor contamination. Reviews of Environmental Contamination and Toxicology, 175, 1–46.Google Scholar
- Canada Mortgage and Housing Corporation. (2009). Lead in older homes. Website from Government of Canada. http://www.cmhc-schl.gc.ca/en/co/maho/yohoyohe/inaiqu/inaiqu_007.cfm. Verified February 9, 2010.
- Culbard, E. B., Thorton, I., Watt, J., Wheatley, M., Moorcroft, S., & Thompson, M. (1988). Metal contamination in British urban dusts and soils. Journal of Environment Quality, 17, 226–234.Google Scholar
- Encyclopædia Britannica. (2009). Anhydrite In: Encyclopædia Britannica Online. Retrieved April 15, 2009 from Encyclopædia Britannica Online: http://www.britannica.com/EDchecked/topic/25417/anhydrite.
- Gooch, J. W. (1993). Lead-based paint handbook. New York: Plenum Press.Google Scholar
- Hammersley, A. P. (1998). FIT2D V10.3 reference manual V4.0. European synchrotron research facility. Paper ESRF98-HA0IT: Grenoble, France.Google Scholar
- Health Canada. (2007). Lead and Health. Health Canada publication 4462, ISBN 978-0-662-44815-0. Available on website. http://www.hc-sc.gc.ca/ewh-semt/pubs/contaminants/lead-plomb-eng.php. Verified May 3, 2010.
- Lanphear, B. P., Hornung, R., Ho, M., Howard, C. R., Eberle, S., & Knauf, K. (2002). Environmental lead exposure during early childhood. Journal of Pediatrics, 40, 40–47.Google Scholar
- MacLean, L. C. W., Beauchemin S., & Rasmussen P. E. (2010). Application of synchrotron X-ray techniques for the determination of metal speciation in (house) dust particles. In C. L. S. Wiseman & F. Zereini (Eds.), Urban airborne particulate matter: Origins, chemistry, fate and health impacts (pp. 193–216). Springer-Verlag, Berlin.Google Scholar
- Morin, G., Ostergren, J. D., Juillot, F., Ildefonse, P., Calas, G., & Brown, G. E. (1999). XAFS determination of the chemical form of lead in smelter-contaminated soils and mine tailings: Importance of adsorption processes. American Mineralogist, 84, 420–434.Google Scholar
- Rasmussen, P. E. (2004b). Can metal concentrations in indoor dust be predicted from soil geochemistry? Canadian Journal of Analytical Sciences and Spectroscopy, 49, 166–174.Google Scholar
- Schwertmann, U., & Cornell, R. M. (1991). Iron oxides in the laboratory. Weinheim, Germany: VCH Publishers.Google Scholar
- Terzano, R., Spagnuolo, M., Vekemans, B., de Nolf, W., Janssens, K., Falkenberg, G., et al. (2007). Assessing the origin and fate of Cr, Ni, Cu, Pb, and V in industrial polluted soil by combined microspectroscopic techniques and bulk extraction methods. Environmental Science and Technology, 41, 6762–6769.CrossRefGoogle Scholar
- Van Alphen, M. (1998). Paint film components. National environmental health forum monographs, General series no. 2, Glenelg Press, Australia.Google Scholar