Lead dust

Dust Lead. Table III, IV, and V show the levels of lead in household dust inside the households in this study. These lead levels were markedly below what is normally found in household dust. Because the levels are inexplicably low, the resulting lead levels in the dust are not considered in the analysis. 

Table III. Distribution of Mean Dust Lead Levels by Study Area...

Table IV. Medians of Dust Lead (lig/cm ) by Distance, Traffic, and Study Area...

Interroute extrapolation. The IEUBK Model includes an exposure module that simulates age-specific lead exposures via inhalation, and ingestion of lead in diet, dust, lead-based paint, soil, and water. The total exposure from each route is defined as the total lead uptake ( pg/day) over a 1-month period. Other routes of exposure may be simulated by the IEUBK Model pending available information from which to characterize both the exposure and media-specific absorption variables. Values for variables in the biokinetic component of the IEUBK Model are independent of the route of exposure. 

Damaged lead-based paint is associated with excessive dust lead levels. Approximately 14 million homes (19% of pre-1980 housing) have more that 5 square feet of damaged lead-based paint, and nearly half (47%) of those homes have excessive dust lead levels (EPA 1995c). 

Lanphear et al. (1996a, 1996b, 1997, 1998b) studied factors affecting PbB levels in urban children and found the following independent predictors of children s PbB levels dust lead loading in homes, African-American race/ethnicity, soil lead levels, ingestion of soil or dirt, lead content and condition of painted... 

Bomschein RL, Succop PA, Krafft KM, et al. 1986. Exterior surface dust lead, interior house dust lead and childhood lead exposure in an urban environment. In Hemphil DD, ed. Trace substances in environmental health. Vol. 20. Columbia, MO University of Missouri 322-332. 

Mielke HW, Adams JL, Reagan PL, et al. 1989. Soil-dust lead and childhood lead exposure as a function of city size and community traffic flow The case for lead abatement in Minnesota. Environ Chem Health 9(Supp) 253-271. 

Pbs=soil lead concentration PbD=dust lead concentration Pbw=water lead concentration PbA0=outside air lead concentration PbAI = inside air concentration PbF=food lead concentration T=relative time spent... 

Heavy dusts Heavy/wet sawdust, metal turnings, foundry tumbling barrels and shake-out, sand blast dust, wood blocks, brass turnings, cast iron boring dust, lead dust 4000-4500 20-23... 

Calculations Visible extinction Estimate of the extinction along a line of sight due to dust, leading to the idea of reddened stars... 

Potula, V., Hegarty-Steck, M. and Hu, H., Blood lead levels in relation to paint and dust lead levels The lead-safe Cambridge program, Am. J. Public Health, 91, 1973, 2001. 

In 1974, at a different place, an attempt to synthesize a 2-acetinone [1,2] by reacting benzonitrile with bromoacetic acid in the presence of zinc dust lead to the preparation of 141 (R = C6H5) in small yield ... 

While there are standards for lead exposure, at this time there is no level that is considered safe, so the best policy is to avoid lead exposure. This is difficult because as a contaminant in food, water, or dust, lead cannot be seen, tasted, or smelled. 

A classical type of dimerization of heterocyclic compounds is the formation of a twin molecule consisting of the same fragments. Such a reaction is known for 2-benzopyrylium salts. Thus, the reduction of the 2-benzopyry-lium salt 261 by zinc dust leads to the intermediate radical 262, which is dimerized in situ to the bisisochromene 263 (76KGS999) (cf. Section IV, B). 

Emond et al. (1997) showed that the method of sampling can significantly influence dust lead and children s blood lead levels. They showed, by field measurements of lead-contaminated... 

Emond MJ, Lanphear BP, Watts A, Eberly S, and Members of the Rochester Lead-in-Dust Study Group (1997) Measurement error and its impact on the estimated relationship between dust lead and children s blood lead. Environmental Research, 72(1) 82-92. 

Clark S, Bornschein RL, Pan W, Menrath W, Roda S, Grote J. 1996. The relationship between surface dust lead loadings on carpets and the blood lead of young children. Environ Geochem Health 18 143-146. 

Increased precipitation over the oceans may increase the supply of a more bioavailable, dissolved aeolian Fe via wet deposition (Fig. 35.5 path 8-9-11 direct effect). During long range transport, dust particles undergo heterogeneous reactions at gas-soHd-Hquid interfaces involving poUution-derived substances that may lead to the increased solubility of aeolian Fe (Dentener et al, 1996 Meshidzke et al, 2003 Underwood et al, 2001). Photochemical reduction in more acidic cloud waters and precipitation promote dissolution of Fe in dust, leading to the production... 

Heavy dusts Metal turnings, sand blast dust, lead dust 4000 500... 

Heavy or moist dust (very heavy dust) Lead dust with small chips, moist cement dust, quick lime dust 4500 and up... 

Lead Group Inc (1999) Research into Ceiling Dust. Lead Action News 7 1. 

Support for the thesis that household dust leads to contamination comes from correlations between biocides in dust and in samples of human origin. This correlation was reported for PCP in the urine of women and children and dust from vacuum cleaner bags (Krause and Englert, 1980), and in PDSP and urine respectively (MeiBner and Schweinsberg, 1996). On the other hand, no correlation was observed between PCP in household dust and blood by Liebl et al. (1996). 

Dust may be regarded as the ideal material for detection and identification of indoor biocides and any of their residues still existing. Commercial vacuum cleaners ean be used for taking samples. Analysis using the < 63-pm fraction of dust lead to results that are more reproducible than those for any other fraction. Reliable results are only obtained under equilibrium conditions in rooms therefore there should be no cleaning for at least one week before dust samples are taken. Since the Umweltsurveys and two case control studies published recently are based on representative samples for household du.st of the German population (especially PCP, lindane and pyrethroids), the assessment of results is possible by comparison with reference values. 

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