Dust, lead sampling

ASTM. 1998b. ASTM E 1644. Standard practice for hot plate digestion of dust wipe samples for the determination of lead by atomic spectrometry. American Society for Testing and Materials. 

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... 

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. 

A homeowner or tenant can also do dust wipe sampling to assess the safety of his or her home. This gives a good indication of how much lead dust is collecting around the home from friction and abrasion or deteriorating paint. 

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. 

The NHANES 2004 PbB survey was accompanied by household dust Pb sampling and the relationships between blood lead and household dust Pb analyzed through various statistical methods (Dixon et al., 2009 Gaitens et al., 2009). There was a statistical association of PbB to floor dust Pb. Child age and other child/family variables as well as year of house construction and window sill and floor Pb were significant predictors of PbB. These workers also calculated via logistic regression analyses that up to 5% of children in homes with floor dust Pb at 12 pg/ft would have a PbB >10 pg/dl. 

A dust-lead hazard is surface dust that contains a mass-per-area concentration of lead equal to or exceeding 40 micrograms per square foot (pg/fC) on floors or 250pg/ft on interior windowsills based on wipe samples. A soil-lead hazard is bare soil that contains total lead equal to or exceeding 400 parts per million (ppm) in a play area or average of 1200 ppm of bare soil in the rest of the yard based on soil samples. 

Before interior renovation activities were performed, the floors and windowsills in the work area and adjacent rooms were cleaned. In most cases, prework cleaning resulted in dust lead levels on floors of less than lOpg/fC nearly all floors were less than 40 J,g/ft before work started. Most windowsills that would be used for later sampling were cleaned to dust lead levels less than 250 j,g/ft. In the few cases where that level was not achieved on a windowsill needed for sampling, dust collection trays were used. Interior renovation activities included the following jobs ... 

Windowsill sample results were similar the geometric mean dust lead levels after renovation activities performed in accordance with the proposed rule exceeded 250 ig/ft only where power planing or a high-temperature heat gun were used. When baseline practices were used, the geometric mean dust lead levels on the windowsills exceeded 250 ig/ft for kitchen cabinet removal, window replacement, high-temperature heat gun use, and power planing. 

Except as provided in 40 CER 745.85(c), this final rule does not allow dust clearance sampling to be performed in lieu of post-renovation cleaning verification. However, some property owners may still choose to have dust clearance sampling performed after the renovation. Dust sampling technicians certified in accordance with this final rule will be available to perform dust clearance sampling after renovations and for the purposes of HUD s Lead-Safe Housing Rule. 

The Environmental Field Sampling Study found that the following activities created dust-lead hazards at a distance of 6 feet from where the work was being performed ... 

Windowsills were also tested. For the dry cloth protocol, 96.4% of the sills that achieved white glove were also confirmed by dust wipe sampling to be below the dust-lead hazard standard for windowsills, and the one sill that did not achieve white glove was also below the standard. For the wet cloth protocol, all of the sills that achieved white glove were also below the dust-lead hazard standard, as were the four sills that did not reach white glove. ... 

EPA proposed to allow optional dust clearance sampling at the completion of renovation activities instead of the postrenovation cleaning verification described in 745.85(b). Some commenters agreed that the decision whether to perform clearance at the conclusion of the job should be left to the home-owner. One commenter asked EPA to require that, if a resident arranged for clearance testing and found lead hazards, the contractor would have to reclean to the resident s satisfaction. 

In response to these comments, EPA has further considered the issue and decided to allow dust clearance sampling instead of cleaning verification only in certain limited situations. EPA agrees with the commenters that, if the rule were to allow clearance sampling instead of verification, EPA would have to require the renovator to achieve clearance, otherwise there would be no check on whether the renovation had been safely performed. HUD s Lead-Safe Housing Rule requires clearance to be achieved in many situations, as do several states. For example, the State of New Jersey requires dust clearance sampling and clearance in certain situations in multi-unit rental housing. 

Therefore, in situations where the contract between the renovation firm and the property owner or another regulation, such as HUD s Lead-Safe Housing Rule or a state regulation, requires dust clearance sampling by a properly qualified person and requires the certified renovator or a worker under the direction of the certified renovator to reclean until clearance is achieved. 

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