Biomonitoring Activities

The current scientific infrastructure to support the committee s research recommendations is severely limited. Improvements in research-related infrastructure are needed to support these recommendations and to enhance the value of biomonitoring activities. The infrastructure needs encompass enhancing laboratory capabilities, expanding the scope and utility of CDC s National Health and Nutrition Examination Survey (NHANES) data, maximizing the use of collected human samples, and fostering international biomonitoring collaboration. Many of these recommendations for infrastructure improvement are cost-effective because they rely on expansion of structures and activities that are already in place. 

Boogaard, P.J. (2007) Human biomonitoring activities - programmes by industry. International Journal of Hygiene and Environmental Health 210 259-261. 

In addition to the similar need for highest representative quality of the sample to be analyzed or to be used as a bioindicator, most general rules and prerequisites of quality control in chemical analysis must be taken into account in biomonitoring activities. During the past 20 years, a strict differentiation between the terms precision (reproducibility) and accuracy (the true value) has been established in chemical analytical research. The practical application of this differentiation makes it possible to determine... 

In this physical methodology, hand-rinsing the volunteers immediately following the activity period removed some test substance from the hands if left on the hands, this substance would have had the opportunity to be absorbed and therefore would have increased the biomonitoring values. In addition, we do not currently know the efficiency of the hand rinse. It is generally thought that the efficiency of the hand rinse using anionic surfactants to remove chlorpyrifos is no better than 50%,5 a value to be determined in future research. 

Pesticide exposure assessment Jazzercize activities to determine extreme case indoor exposure potential and in-use biomonitoring... 

If a further refinement of the determination of exposure is necessary, an exposure study using the product of concern and conducted under conditions of real practice might be required. The exposure study may include passive dosimetry or biomonitoring, depending on the properties of the active substance and the data on metabolism and toxicokinetics in mammals. 

Fig. 6 Biomonitoring of pollution in the Ebro Delta with Daphnia magna and Corbicula fluminea. (a) Map of sampling sites. Site 1 is out of the figure limits, close to Amposta (see Fig. 1). (b) Assays for neurotoxic activity (ChE and CbE) and D. magna feeding). Note the different pattern for the microcrustacean (sensitive to insecticides), which show a maximal toxic (inhibitory) effect in May and June, and the mollusk (relatively resistant), (c) Oxidative stress markers. These markers showed a similar response for both species with maximal effects (activation) in May (month 5) and August (month 8). Data from [43] and [44], Dm and Cf identify markers from D. magna and C. fluminea, respectively...

Schmitt, C.J., M.L. Wildhaber, J.B. Hunn, T. Nash, M.N. Tieger, and B.L. Steadman. 1993. Biomonitoring of lead-contaminated Missouri streams with an assay for erythrocyte delta-aminolevulinic acid dehydratase activity in fish blood. Arch. Environ. Contam. Toxicol. 25 464-475. 

Presently available methods to diagnose and biomonitor exposure to anticholinesterases, e.g., nerve agents, rely mostly on measurement of residual enzyme activity of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) in blood. More specific methods involve analysis of the intact poison or its degradation products in blood and/or urine. These approaches have serious drawbacks. Measurement of cholinesterase inhibition in blood does not identify the anticholinesterase and does not provide reliable evidence for exposure at inhibition levels less than 20 %. The intact poison and its degradation products can only be measured shortly after exposure. Moreover, the degradation products of pesticides may enter the body as such upon ingestion of food products containing these products. 

When evaluating the safety of chemicals in humans, it is very important to know the fate of chemicals in the human body and the amounts of exposure in daily activity. This section reviews the metabolic reactions of pyrethroids in humans, and the biomonitoring of pyrethroid metabolites in human urine for the exposure assessment. Mathematical modeling is a useful tool to predict the fate of chemicals in humans. This section also deals with the recent advance of mathematical modeling of pyrethroids to predict the pharmacokinetics of pyrethroids. 

Legler, J., Leonards, P., SpenkeUnk, A., Murk, A.J. (2003). In vitro biomonitoring in soUd phase matrices reveals the presence of unknown compounds with estrogenic activity. Ecotoxicology, 12 239-249. 

Loppi, S. Bonini, I. 2000. Lichens and mosses as biomonitors of trace elements in areas with thermal springs and fumarolic activity (Mt. Amiata, Central Italy). Chemosphere, 41, 1333-1336. 

Continuum of Risk-Assessment and -Management Activities Related to Exposure Biomonitoring, 74... 

Although ILSI-HESI is not directly involved in collecting biomonitoring data, it is actively researching their interpretation and potential regulatory... 

A number of environmental groups have been actively involved in collecting biomonitoring data in the United States, Canada, and Europe. Those organizations include the Environmental Working Group (EWG), the World Wildlife Fund (WWF), Commonweal, and Environmental Defence (based in Canada). The studies have often been conducted on a smaller scale and with samples from a few people in a select region. Examples are discussed below. 

Of the European studies reviewed, many measured heavy metals, cotinine, PCBs, pesticides, PAHs, dioxins, phthalates, and VOCs. Germany has taken a substantial lead in this respect through its comprehensive population-based surveys (German Environment Surveys) and concerted efforts to develop health-protective reference values for the general population. In addition European countries have been actively involved in occupational biomonitoring efforts. In fact, some countries have biomonitoring surveillance programs that have been required by law. 

APHL (American Public Health Laboratories). 2006. Recent Activities. Biomonitoring in the States The APHL Minute 1 12-13 [online]. Available https //www.aphl.org/docs/ newsletter/january february 3.pdf [accessed Jan. 18,2006]. 

Utah Department of Health. 2006. Environmental Public Health Tracking Biomonitoring. Utah Department of Health, Office of Epidemiology [online]. Available http //health. utah.gov/els/epidemiology/envepi/activities/EPHTP/ephtb.htm [accessed Jan. 18, 2006]. 

All those activities have specific purposes and may be conducted alone (for example, for priority-setting among public-health actions) or as parts of a multitier strategy. Links between risk-assessment and -management activities (why biomonitoring is conducted) and the properties of the biomarkers (what characteristics our biomonitoring tools need to have for us to be able to conduct these activities) will be presented below. 

It is usual whenever biologic samples are obtained in medical practice or in any health encounter for results to be expressed in relation to normal. In fact, a relationship to normal is the question almost every subject asks first when presented with such information. For biomonitoring results, it is a generally meaningless question— normal for human-made chemicals or chemicals that did not enter the environment except for human activity, is actually zero. Despite that, many laboratories report results, such as blood lead concentrations, in just this way—a practice likely to result in confusion. For example, it is not rare to see reports of blood concentrations that contain the phrase normal for industrial workers. In truth, such concentrations may be common in industrial workers, or even typical, but hardly normal in the usual meaning of that word in relation to health. Such comparisons are especially problematic for biomarkers whose relationship to health and environmental sources is less well studied. The discussion below touches briefly on the scientific issues raised by such implicit or explicit comparisons of results with reference ranges. 

---