Environmental lead exposure measure

Pocock SJ, Smith M, Baghurst P Environmental lead and children s intelligence a systematic review of the epidemiological evidence. BMJ 309 1189-1197, 1994 Rice DC The health effects of environmental lead exposure closing Pandora s box, in Behavioral Measures of Neurotoxicity. Edited by Russell RW, Llattau PE, Pope AM. Washington, DC, National Academy Press, 1990, pp 243-267... 

Trace-metal-clean techniques are also necessary in analysis of clinical samples with relatively low lead concentrations. This is illustrated by the relative contribution of contaminant lead in measurements of elevated (50 fig/dL) and low (1 /xg/dL) PbB (Fig. 8). Moreover, the importance of these techniques will increase in clinical settings with projected declines in environmental lead exposures to humans in the U.S. and elsewhere (Brody et al. 1994 Flegal and Smith 1992b Smith and Flegal 1995). 

ALAD, an enzyme occurring early in the heme pathway, is also considered a sensitive indicator of lead effect (Hemberg et al. 1970 Morris et al. 1988 Somashekaraiah et al. 1990 Tola et al. 1973). Because there is no well-defined blood lead threshold at which inhibition of ALAD does not occur, it allows measurement of the effect on the general population at environmental lead levels and does not require high exposure levels as with occupational workers (Hemberg et al. 1970). However, ALAD activity may also be decreased with other diseases or conditions such as porphyria, liver cirrhosis, and alcoholism (Somashekaraiah et al. 1990). 

Hu H Department of Environmental Health, Boston, MA Measure in vivo bone lead level in a National Institute of new longitudinal study of lead exposure Environmental Health and reproduction among married Sciences women and men ... 

Wolff MS Mount Sinai School of Medicine of CUNY, New York, NY Analytical support for comprehensive assessment of lead exposures body burden measures will include blood lead, plasma lead, ZPP, bone lead, representing multiple compartments for deposition of lead and widely variable rates of elimination measurement of total lead in soil extracts to validate quantitative measures National Institute of Environmental Health Sciences... 

Flegal AR, Smith DR. 1995. Measurements of environmental lead contamination and human exposure. Rev Environ Contam Toxicol 143 1-45. 

Trillingsgaard, A., O.N. Hansen, and I. Beese. 1985. The Bender-Gestalt Test as a neurobehavioral measure of preclinical visual-motor integration deficits in children with low-level lead exposure. Pp. 189-193 in WHO Environmental Health, Document 3. Neurobehavioral Methods in Occupational and Environmental Health, Second International Symposium, Copenhagen, Denmark, Aug.6-9,1985. Copenhagen, Denmark World Health OrganizatioiL... 

Measuring lead exposure in infants, children, and other sensitive populations. Board Environmental Studies and Toxicology, National Research Council, Washington, DC, (1993). 

For measuring lead in environmental media providing potential human lead exposures, this chapter includes older published data for lead concentrations in media, data which are old enough to encompass the full lifetimes of living populations. This is because of long-term Pb storage in bone. One concern with any appraisal of older lead measurement data in media is that of analytical and statistical data reliability versus that of methods employed with more recent accepted techniques. Sensitivity is of particular concern. A potent toxicant such as environmental lead requires methods for quantification of concentrations of lead at ultra-trace levels in order to permit estimates of the full range of Pb exposures. 

Environmental media of interest in this section on measurement are the same as those producing potential human lead exposures ambient air, lead paints, diet, drinking water, soils and dusts, and some of the more problematic idiosyncratic sources. Sampling and laboratory measurement techniques now widely used are emphasized with comparative statements for older methods provided mainly to offer perspective. Biomarker sampling and measurement methodologies, i.e., procedures for lead in biological media directly relevant to human lead exposures, are presented in a later chapter. 

Concentrations of lead in the various environmental media described in this section are presented for extended periods. The available data that meet minimal statistical and measurement criteria generally only extend from the late 1960s/early 1970s to the present. The purposes of a wide temporal look at environmental lead concentrations are several. First, the nature of lead as an accumulating contaminant in the bodies of human populations requires an appreciation of the amounts of environmental lead that existed in past decades. As noted earlier, lead levels in media have been changing, mainly downward, so that current human body lead burdens are only partially quantifiable from current lead intakes into body compartments. Secondly, the use of predictive, biokinetic models of human lead exposures for simulating Ufe-time lead exposures requires knowledge of lead intakes from the earliest periods of life. 

National Academy of Sciences National Research Council, 1993. Measuring Lead Exposure in Infants, Children, and Other Sensitive Populations. National Academy Press, Washington, DC. Nriagu, J.O., 1983. Lead and Lead Poisoning in Antiquity, lohn Wiley Sons, New York. Nriagu, J.O., 1985. Historical perspective on the contamination of food and beverages with lead. In Mahaffey, K.R. (Ed.), Dietary and Environmental Lead Human Health Effects. Elsevier, New York, pp. 1—41. 

Consequently, this review is designed to briefly summarize many of the available techniques for accurate measurements of environmental and human lead contamination. This includes the importance of ultraclean techniques for lead analysis as well as brief descriptions of some current and emerging analytical techniques for measuring lead exposures in humans. The descriptions are preceded by abbreviated discussions of the chemical properties of lead, natural and anthropogenic variations in its stable isotopic composition, and historical records of lead contamination in the environment. The report concludes with a summary of some indirect methods of measuring lead exposure and toxicity in humans. Much of the material in this report is based on reviews written for several recent reports Measuring Lead Exposure in Infants, Children, and Other Sensitive Populations (NRC 1993), Lead in the Biosphere Recent Trends (Smith and Flegal 1995), and In Vivo Measurement and Speciation of Nephrotoxic Metals (Smith and McNeill 1995). 

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