Laserfiche WebLink
219 <br /> 6. ANALYTICAL METHODS <br /> digesting samples with acid and analyzing by either AAS or the more sensitive GFAAS (Chau et al. 1980; <br /> FPA 1982c, 1986e). <br /> Dusts, Sediments, and Soil. Both total and organic lead have been determined in dusts, sediments, and <br /> ;oils. In most cases the sample must be digested with acid to break down the organic matrix prior to <br /> analysis (Beyer and Cromartie 1987; Bloom and Crecelius 1987; EPA 1982c, 1986e; Krueger and Duguay <br /> 1939; Que Hee and Boyle 1988; Que Hee et al. 1985b; Schmitt et al. 1988), although organic extraction <br /> jChau et al. 1979) and purge-and-trap (Chau et al. 1980) have been used. The primary detection methods <br /> etre AAS or GFAAS with GFAAS more sensitive, but also more susceptible to interference. When <br /> Iuantification of organic lead is desired, GC is employed to separate the alkyl lead species (Chau et al. <br /> '1979,1980). Precision and accuracy are acceptable for these atomic absorption-based methods (Beyer and <br /> =Cromartie 1987; Bloom and Crecelius 1987; Chau et al. 1979; EPA 1982c, 1986e; Krueger and Duguay <br /> 1989; Que Hee et al. 1985b). ICP-AES is reported to be more sensitive and reliable than atomic <br /> Ibsorption techniques (Schmitt et al. 1988), but sample collection and preparation methods have been <br /> 11 <br /> hown to strongly influence the reliability of the overall method (Que Hee et al. 1985b). Sampling of - <br /> �house dust and hand dust of children requires special procedures (Que Hee et al. 1985b). XRFS appears <br /> io provide a simpler method of measuring lead in soil matrices; however, the available data do not permit <br /> n assessment of the techniques sensitivity and reliability for soil analysis (Krueger and Duguay 1989). <br /> ether Matrices. Lead has been determined in several other environmental matrices, including paint, fish, <br /> vegetation, agricultural crops, and various foods. As with soil, the methods of choice are either ICP-AES, <br /> SAS, or GFAAS. Samples may be prepared using one of the methods described for sediment and soil <br /> )r by wet or dry ashing (Aroza et al. 1989; Capar and Rigsby 1989; Que Hee and Boyle 1988; Que Hee <br /> ,t al. 1985b; Satzger et al. 1982). ASV and DPASV have also been used with good sensitivity (ppb) and <br /> reliability to analyze for lead in other environmental media (Capar and Rigsby 1989; Ellen and Van Loon <br /> 1990; Satzger et al. 1982). <br /> 113 ADEQUACY OF THE DATABASE <br /> Section 104(i)(5) of CERCLA, as amended, directs the Administrator of ATSDR (in consultation with <br /> to Administrator of EPA and agencies and programs of the Public Health Service) to assess whether <br /> Idequate information on the health effects of lead is available. Where adequate information is not <br /> mailable, ATSDR, in conjunction with NTP, is required to assure the initiation of a program of research <br /> 1eSigned to determine the health effects (and techniques for developing methods to determine such health <br /> affects) of lead. <br /> the following categories of possible data needs have been identified by a joint team of scientists from <br /> aTSDR, NTP, and EPA. They are defined as substance-specific informational needs that if met would <br /> educe or eliminate the uncertainties of human health assessment. This definition should not be <br /> �terpreted to mean that all data needs discussed in this section must be filled. In the future, the <br /> dentified data needs will be evaluated and prioritized, and a substance-specific research agenda will be <br /> Proposed. <br /> 63.1 Identification of Data Needs <br /> ethods for Determining Biomarkers of Exposure and Effect. Methods are available for measuring <br /> organic lead in blood, serum, urine, cerebrospinal fluid, tissues, bone, teeth, and hair (Aguilera et al. <br /> 989; Batuman et al. 1989; Blakley and Archer 1982; Blakley et al. 1982; Christoffersson et al. 1986; Delves <br /> P <br />