Vacuum dust sample

Most indoor studies report metal concentrations in vacuum dust samples using mass concentration units (jug g Table 11.1). In studies aimed at estimating residential exposures, settled dust samples typically are col-... 

The objective of this synchrotron application was to determine the Pb speciation in the fine fraction (<80 pm) of an archived vacuum dust sample collected from a... 

Samples were either prepared by direct addition of polymer to solvent (Method I) or by a careful method to reduce dust (Method II) In Method II, PBLG was added from a stock solution in distilled DMF via a 0 2ym filter (Millipore type FG) into preweighed cells that had been exhaustively rinsed with nearly dust-free water from a Millipore 4 stage purifier and dried Under vacuum, the samples were either concentrated or evaporated to dryness, depending respectively on whether a PBLG/DMF or PBLG/toluene sample was desired For... 

The most frequently used methods for sampling indoor surface dust for SVOC/ POM analysis is simply to use dust from a vacuum cleaner dust bag, see for example, Krause, Chutsch and Englert (1989), or a special vacuum cleaner mouthpiece containing a filter, see for example, 0ie, Hersoug and Madsen (1997). Both the mouth-piece and the filter should be cleaned prior to use. It must be assured that the SVOCs and POMs of interest are quantitatively captured by the filter (e.g., phthalates are quantitatively captured by quartz fiber filters (Clausen and Wolkoffi 1997b)) and that the vacuum cleaner exhaust does not contaminate the samples with for example, phthalates. However, the vacuum cleaner sampling method is probably very dependent on the sampling conditions (e.g., carpet or hard floor... 

To avoid the problems with vacuum cleaner surface dust sampling a special surface dust sampler, HVS-3, was developed (Roberts et al, 1991). The sampler consists of a nozzle that can be adjusted to a well defined distance to the surface, a cyclone that collects the dust particles, an air pump, and an exhaust filter to capture particles that are not retained in the cyclone. SVOCs may break through the cyclone as vapors and a PUF plug can be inserted after the cyclone. HVS-3 has been modified to ensure a more constant suction pressure and volume, and a known sampled area (Gyntelberg et al, 1994). The design and use of the HSV3 has now been standardized (ASTM, 1997, D 5438-94). 

Lewis et al. (1999) prepared a gross house dust sample by combing dust from four vacuum cleaner bags obtained from 25 middle-class homes. The composite dust was separated into seven size fractions ranging from <4 to 500 micrometer in diameter. Ten PAHs were analyzed. All of the ten target PAHs were detected... 

Indoor household dust samples gathered by a vacuum cleaner from rooms with furniture treated with a wood-preserving formulation were analyzed for CDDs (Christmann et al. 1989b). The wood-preserving... 

Several other types of hand-held vacuum samplers have been used to collect dust from residential surfaces. One of these, the Baltimore Repair and Maintenance Study Cyclone Sampler (BRMCS) (Farfel et al 1994), has been evaluated against the HVFS. The BRMCS uses the same cyclone and catch bottle assembly as the HVS3, but a different nozzle and vacuum source. The vacuumed dust is sucked into the cyclone via a semi-rigid Tygon hose (2.54-cm o.d.) that is notched on the sampling end to simulate a nozzle. Suction is provided by a small, hand-held vacuum device (Royal Hand Vac , Model 553, 2 A). The collection efficiency for the BRMCS was determined to be 44.1 % n =6, s = 3.8) for plush uylou carpet, 61.1 % (n = 6, = 6.7) for level loop carpeting, 71.8-87.8 % n =6, s = 3.5) for upholstery and 84.7 % n = 3, s = 2.3) for wood surfaces (USEPA, 1996b). 

Auother dust sampler that uses a haud-held vacuum cleaner but is capable of collectiug large dust samples was desigued by Rudel et al. (2001). The method employs a Eureka Mighty-Mite vacuum cleaner (8 A) (The Eureka Company, Bloomington, IL, USA) with the dust bag replaced by a 19-uun x 90-mm cellulose Soxhlet extraction thimble contained in a special PTFE sampling module. 

Colt, J.S., S.H. Zahm, D.E. Camann and P. Hartge (1998). Comparison of pesticides and other compounds in carpet dust samples collected from used vacuum cleaner bags and from a high-volume surface sampler. Environ. Health Perspec., 106, 721-724. 

Concentrations of pesticides in indoor environments are dependent on their usage. Dust samples, for example, collected using vacuum cleaners, in households where wood preservatives were applied showed a median value of 13 mg g" of PCP, as compared with 0.008 mg g in samples from the control group [13]. 

Dust samples exactly 7-days old, collected by vacuuming according to VDI guideline 4300, part 8 [84], no sieving ( =33). 

House dust serves as a reservoir for pesticides in households [85]. Dust ingestion scenarios show that exposures could also exceed the diazinon chronic reference dose [115]. Support for the thesis that household dust may not only be a direct exposure path but may serve as an indicator for all indoor exposure paths can be concluded from correlations between pesticides in dust and in samples of human origin. Regarding PCP, a semivolatile pesticide, concentrations in urine of women and children corresponded well with indoor dust samples from vacuum cleaner bags [13,136]. 

The choice of dust sampling method depends on the purpose of the study. A number of publications compare various wipe and vacuum methods for Pb sampling (e.g., U.S. EPA, 1995 Sutton etal., 1995 Laxen et ah, 1988). Wipe methods have the advantage of being simple and inexpensive compared to vacuum techniques. However, vacuum methods have some distinct advantages over common wipe methods vacuum... 

Whereas the analytical part of the determination of biocides in dust displays only minor differences, samples referred to as household dust vary significantly. So far, no standard protocol for dust sampling has been reported. In the United States a High Volume Small Surface Sampler (HVS3) collecting dust samples of 2-100 g from carpets and bare floors in about 15 min has been developed (Roberts and Dickey, 1995). In Germany, predominantly dust samples from vacuum cleaner bags collected by commercial vacuum cleaners are used for evaluation of biocides in some cases samples were analyzed in passively deposited suspended particulate (PDSP) (Krause et al.. 

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. 

First, but very few, results on the occurrence of phthalates indoors were collected by Warns.The first report on the occurrence of a flame retardant plasticizer in house dust was on TDCPP. Sellstrom and Jansson mentioned it to be present in one out of two Swedish dust samples (from vacuum cleaner bags) but gave no concentration. In the last years however, quite a few results on phthalates and organophosphate plasticizers have been published. Some of them are compiled in Tables 17.5.5 and 17.5.6. 

House dust, exactly one week old, sampled with commercial vacuum cleaners (Germany), analysis of total dust, values given are the average of 3 laboratories participating in an inter-laboratory exposure study. House dust sampled with commercial vacuum cleaners (Germany), analysis of total dust. 

As set forth in U.S. HUD (1995), dust sampling by use of surface wipes is preferred on the basis of ease of use, relative cost, and a generally favorable performance record for routine samplings. For example, children s blood lead levels and dust wipe lead content in the same units are well correlated (Farfel et al., 1994 Lanphear et al., 1995). Certain vacuum collection approaches can also be used with trained operators in research studies. Measuring dust lead loading from hard surfaces is more reliable than firom complex surfaces such as upholstery or carpeting (Ewers et al., 1994). 

Dust sampling for evaluation of residences as part of hazardous waste site evaluations as occur in Superfund activities entails determination of dust lead concentration, usually by vacuum collection through use of vacuum cleaners (von Lindem et al., 2003b) or, preferably, filter collection units attached to vacuum sources. 

Carpet Do dust sampling to determine No occupancy during Carefully remove and package HEPA vacuum floor... 

Vacuum cleaner bags provide many researehers with dust samples. In general, this method has proved ineffective, largely beeause of the wide range in the efficiency of the typical vacuum cleaner bag. Furthermore, this method does not measure pg/m and thus fails to give a measure of dust loading. 

Preparation of REAOENTS.t It is essential for this preparation that the zinc powder should be in an active condition. For this purpose, it is usually sufficient if a sample of ordinary technical zinc powder is vigorously shaken in a flask with pure ether, and then filtered off at the pump, washed once with ether, quickly drained and without delay transferred to a vacuum desiccator. If, however, an impure sample of zinc dust fails to respond to this treatment, it should be vigorously stirred in a beaker with 5% aqueous sodium hydroxide solution until an effervescence of hydrogen occurs, and then filtered at the pump, washed thoroughly with distilled water, and then rapidly with ethanol and ether, and dried as before in a vacuum desiccator. The ethyl bromoacetate (b.p. 159 ) and the benzaldehyde (b.p. 179 ) should be dried and distilled before use. 

Sampling in small diameter vacuum ducts resulted in higher vacuum pressures, flow velocities, dust concentrations and charge densities, but lower flow rates. 

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