|
220
<br /> 6. ANALYTICAL METHODS
<br /> and Campbell 1988; Ellen and Van Loon 1990; Exon et al. 1979; Hu et al. 1989, 1990, 1991; Jason and
<br /> Kellogg 1981; Manton and Cook 1984; NIOSH 1977a, 1977d, 1977e, 1977f, 1977g 1977h; Que Hee and
<br /> Boyle 1988; Que Hee et al. 1985a; Wielopolski et al. 1986). Available methods for determining lead in
<br /> body fluids are sensitive and reliable for measuring background exposure levels, as well as exposure levels the i
<br /> at which health effects have been observed to occur. Blood lead levels have been found to correlate best nedia
<br /> with exposure concentrations (Rabinowitz et al. 1985). Methods of quantifying lead in tissues, bone, teeth, TSL
<br /> and hair are generally reliable, but are only sensitive at relatively high exposure concentrations. There is Rte)
<br /> a need for more sensitive methods of detection for matrices so that correlations between lead levels in
<br /> these media and exposure concentrations can be more reliably determined. Several nonspecific biomarkers letnot
<br /> are used to assess exposure to lead. These include ALAD activity and ALA, EP, coproporphyrin, and 1,25- ;mica
<br /> dihydroxyvitamin D concentrations (Braithwaite and Brown 1987; EPA 1986a; Grandjean and Olsen 1984; �11kyl I
<br /> Stokinger 1981; Tabuchi et al. 1989; Tomokuni and Ichiba 1988; Tomokuni et al. 1988). The methods for 12lue
<br /> determining these variables are sensitive, reliable, and well established. No additional research for these The F
<br /> biomarkers appears to be needed. 1,000,
<br /> Existing methods for measuring lead in biological fluids and tissues are the same as those for exposure. CEPA
<br /> The limitations and anticipated research needs are the same in that there is a need for improved methods that It
<br /> inhale
<br /> of quantifying lead in tissues, bone, teeth, and hair. The primary biomarkers of effect for lead are ALAD, Lancer
<br /> EP, basophilic stippling and premature erythrocyte hemolysis, and presence of intranuclear lead inclusion
<br /> I;tate,
<br /> bodies in the kidneys. Sensitive, reliable, well-established methods exist to monitor for these biomarkers; Additi
<br /> however, they are not specific for lead exposure. Iprocec
<br /> Methods for Determining Parent Compounds and Degradation Products in Environmental Media. The C
<br /> Numerous analytical methods are available for measuring inorganic and organic lead compounds in air, 1991).
<br /> water, sediments, soil, fish, agricultural products, and foodstuffs (Eckel and Jacob 1988; EPA 1982a, 1986a,
<br /> 1988b, 1988f, 1989f, 1989h, 1990c; Lee et al. 1989; Maenhaut et al. 1979; Mielke 1992; Mielke et al. 1983, In an
<br /> 1985, 1989). Most of these are sensitive and reliable for determining background concentrations of lead KCLC
<br /> compounds in the environment and levels at which health effects might occur. The most frequently used improi
<br /> methods are AAS, GFAAS, ASV, and ICP-AES, the methods recommended by EPA and NIOSH (Birch the wa
<br /> et al. 1980; EPA 1988b; NIOSH 1977c, 1981, 1984; Scott et al. 1976). The definitive method is IDMS, lead ir.
<br /> which is used to produce reference standards by which laboratories can determine the reliability of their of tare
<br /> analyses (Volkening et al. 1988). No additional analytical methods for determining low levels of lead treatm
<br /> compounds in environmental media are needed. if lead
<br /> 6.3.2 On-going Studies Lead i
<br /> o
<br /> FL Milder (Applied Biomedical Corporation, Massachusetts) is developing a technique using X-ray electro
<br /> fluorescence in a transmission geometry to measure total lead, in vivo, noninvasively. The distribution of Manu ,
<br /> lead bone stores in cadavers will be investigated and results will be used to design and build a prototype finisht
<br /> machine for measuring lead in humans. Ultimately, the machine developed will be useful as .(1) a and elf
<br /> diagnostic tool in determining the presence of lead poisoning and elevated levels of body lead; (2) a
<br /> monitoring device in following the progress of chelation treatment; and (3) a screening device to The Lr
<br /> complement or replace erythrocyte protoporphyrin testing in children and to do epidemiologic studies in (1) req
<br /> adults and children. No additional information concerning methods for measuring lead in biological and drinkin
<br /> environmental samples was located. establi�
<br /> Water i
<br /> CDC o
<br /> Record
<br />
|