Deposition, resuspension, and penetration of particles within a residence

https://ira.lib.polyu.edu.hk/bitstream/10397/2570/1/B29%20Review%20on%20Urban%20Environmental%20Geochemistry%202006.pdf

Urban environmental geochemistry of trace metals.

This review shows the equal or greater importance of leaded gasoline-contaminated dust compared to lead-based paint to the child lead problem, and that soil lead, resulting from leaded gasoline and pulverized lead-based paint, is at least or more important than lead-based paint (intact and not pulverized) as a pathway of human lead exposure. Because lead-based paint is a high-dose source, the biologically relevant dosage is similar to lead in soil. Both lead-based paint and soil lead are associated with severe lead poisoning. Leaded gasoline and lead in food, but not lead-based paint, are strongly associated with population blood lead levels in both young children and adults. Soil lead and house dust, but not lead-based paint, are associated with population blood lead levels in children. Most soil lead and house dust are associated with leaded gasoline. Lead-based paint dust is associated with cases of renovation of either exterior or interior environments in which the paint was pulverized. Based upon the limited data to date, abatement of soil lead is more effective than abatement of lead-based paint in reducing blood lead levels of young children. About equal numbers of children under 7 years of age are exposed to soil lead and lead-based paint. Seasonality studies point to soil lead as the main source of population blood lead levels. Soil lead is a greater risk factor than lead-based paint to children engaged in hand-to-mouth and pica behavior. In summary, soil lead is important for addressing the population of children at risk of lead poisoning. When soil lead is acknowledged by regulators and the public health community as an important pathway of human lead exposure, then more effective opportunities for improving primary lead prevention can become a reality.

Soil is an important pathway of human lead exposure.

Trace elements in street and house dusts: sources and speciation.

A total of 106 street and household dusts have been sampled throughout Bahrain and analyzed for Pb, Zn, Cd, Ni and Cr using the atomic absorption spectrophotometric method. The sampling sites were divided into seven categories, including the control site. Results showed that dust samples contained significant levels of the metals studied compared with the control values. The mean values for Pb, Zn, Cd, Ni and Cr in street dust were 697.2, 151.8, 72.0, 125.6 and 144.4 μg g−1 respectively, whereas for household dust they were 360.0, 64.4, 37.0, 110.2 and 144.7 μg g−1. These values suggest that motor vehicles form a major source of these metals in dust samples. The values of heavy metals in dust samples in this study were compared with values found in other investigations in various countries. With respect to Ni, elevated concentration could be attributed to smoke from the burning of Kuwait oil fields. Also correlations between metal levels in dust samples for all the metals were investigated. Our results show that heavy metal levels in various sites in Bahrain are similar, which indicate that Bahrain can be considered as one big urban center with high population and traffic density.

Heavy metals in street and house dust in Bahrain

In and around well-kept homes painted with low lead paints situated in a small urban community, large amounts of lead and cadmium are found. High trace metal amounts are also found at nonresidential sites. Much of the lead is probably of automotive origin. Lead levels in dusts within homes average 600 ppM and 680 ..mu..g/m/sup 2/. In nonresidential interiors, dusts average 1400 ppM Pb and 2040 ..mu..g Pb/m/sup 2/. Unexpectedly high cadmium accumulations are found, especially in carpet dusts from rubber-backed carpets. High nonresidential settled dust and soil lead contents are due to higher traffic flows. The lead content of outdoor residential dust is 600-1950 ppM and 90-6640 ..mu..g/m/sup 2/. These values increase several times around nonresidential sites. Lead and cadmium from trace urban dusts are a significant addition to the child body burden.

John W. Hartford

Papers

Lead and cadmium in dusts and soils in a small urban community