Elements and Their Compounds in Indoor Environments

Hassan

et al. 2010

Water Air Soil Pollut

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Trace elements, especially those associated with fine particles in airborne particulate matter (PM), may play an important role in PM adverse health effect. The aim of this paper is to characterize elements in a wide particle size range from nano (57-100 nm) to fine (100-1,000 nm) and to coarse (1,000-10,000 nm) fractions of two urban PM samples collected in Ottawa. Size-selective particle sampling was performed using a micro-orifice uniform deposit impactor, and element concentrations were determined in each different size fraction by inductively coupled plasma-mass spectroscopy. A general trend of increasing element concentration with decreasing aerodynamic diameter was observed for elements V, Mn, Ni, Cu, Zn, Se, and Cd, indicating they were predominately concentrated in the nanoparticle size range. Other elements including Fe, Sr, Mo, Sn, Sb, Ba, and Pb were predominately concentrated in the fine-size range. Increased concentration of elements in the nano and fine particle size range is significant due to their ability to penetrate into the deepest alveolar area of the lungs. This was confirmed by the calculation of median concentration diameters, which were less than 800 nm for most of the investigated elements. Particle size distribution and element correlation analysis suggest that the elements concentrated in the nano-and fine-size fractions originated mainly from vehicular combustion and emission. Long-range airborne transport and soil or road dust resuspension may also contribute. Particle size had an important effect on element bioaccessibility for the studied urban PM samples showing a general trend of increasing element bioaccessibility with decreasing particle size. These results emphasize the importance of acquiring information on nano and/or fine PM-bound elements and their bioaccessibilities for accurate element and PM exposure assessment.

Section: Ehc-93 Samplesmentioning

confidence: 98%

Section: Particle Size Dependent Bioaccessibilitymentioning

confidence: 99%

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Concentration Distribution and Bioaccessibility of Trace Elements in Nano and Fine Urban Airborne Particulate Matter: Influence of Particle Size

Niu

Hassan

et al. 2010

Water Air Soil Pollut

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“…The literature indicates that indoor/outdoor metal concentration ratios (I/O ratios) vary widely depending on proximity to exterior metal sources, exceeding unity in residential settings with low impact from industrial sources, to less than unity in the vicinity of geochemical "hotspots" where elevated soil concentrations occur due to industrial and/or geological sources (Rasmussen 2004a). …”

Section: Introductionmentioning

confidence: 98%

Influence of Matrix Composition on the Bioaccessibility of Copper, Zinc, and Nickel in Urban Residential Dust and Soil

Human and Ecological Risk Assessment: An International Journal

Beauchemin

Nugent

et al. 2008

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This study examines factors affecting oral bioaccessibility of metals in household dust, in particular metal speciation, organic carbon content, and particle size, with the goal of addressing risk assessment information requirements. Investigation of copper (Cu) and zinc (Zn) speciation in two size fractions of dust (<36 µm and 80-150 µm) using synchrotron X-ray absorption spectroscopy (XAS) indicates that the two metals are bound to different components of the dust: Cu is predominately associated with the organic phase of the dust, while Zn is predominately associated with the mineral fraction. Total and bioaccessible Cu, nickel (Ni), and Zn were determined (on dry weight basis) in the <150 µm size fraction of a set of archived indoor dust samples (n = 63) and corresponding garden soil samples (n = 66) from the City of Ottawa, Canada. The median bioaccessible Cu content is 66 µg g −1 in dust compared to 5 µg g −1 in soil; the median bioaccessible Ni content is 16 µg g −1 in dust compared to 2 µg g −1 in soil; and the median bioaccessible Zn content is 410 µg g −1 in dust compared to 18 µg g −1 in soil. For the same data set, the median total Cu content is 152 µg g −1 in dust compared to 17 µg g −1 in soil; the median total Ni content is 41 µg g −1 in dust compared to 13 µg g −1 in soil; and the median total Zn content is 626 µg g −1 in dust compared to 84 µg g −1 in soil. Organic carbon is elevated in indoor dust (median 28%) compared to soil (median 5%), and is a key factor controlling metal partitioning and therefore bioaccessibility. The results show that house dust and soil have distinct geochemical signatures and should not be treated as identical media in exposure and risk assessments. Separate measurements of the indoor and outdoor environment are essential to improve the accuracy of residential risk assessments.

“…A key pathway of childhood exposure to lead (Pb) is ingestion of soil and house dust (Culbard et al 1988;Lanphear et al 2002;Butte and Heinzow 2002;Rasmussen 2004a). The main sources of Pb in indoor residential dust include deteriorating lead-based paints, tracking-in of soils and street dusts, and penetration of airborne dust particles (e.g.…”

Section: Introductionmentioning

confidence: 99%

Lead speciation in indoor dust: a case study to assess old paint contribution in a Canadian urban house

Beauchemin

MacLean

2011

Environ Geochem Health

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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.