Hair mineral analysis in the assessment of human exposure to metals

Abstract

Exposure of human to toxic metals in one of the mostly significant problems related with pollution of the environment. Additional anthropogenic emission of these toxicants increased their mobility and consequently led to accumulation in biotic elements of the environment. Resulting, biomonitoring is becoming a required part of global environmental monitoring system. The chapter briefly describes the application of hair mineral analysis in the assessment of human exposure to metals from various sources. The content of elements in hair serves, among other biomonitors, as an example of biomarker of exposure. Elemental composition of human hair - normal ranges and mean values, growth rate - are delivered. Usefulness of hair mineral analysis in environmental biomonitoring, occupational toxicology, early prognosis of some diseases is exemplified. Additionally, the historical background of mineral analysis of hair is covered, similarly as using hair in the explanation of some historical facts. Analytical approach towards multielemental analysis of human hair from sampling, through sample digestion, finishing with the analysis itself, is discussed. The problem of validity of hair mineral analysis in the assessment of exposure to several metals is claimed. Factors influencing the levels of elements in hair, which were related with either exposure or individual characteristics are pointed out. Examples of the application of hair mineral analysis are presented: Biomonitoring of environmental pollution, identification of exposure at a workplace or exposure to metals from orthodontic appliances. The reference ranges for several elements in hair are presented and discussion about changes according to specific diseases is covered. An example of basic questionnaire for the subjects is provided. Statistical elaboration of data from questionnaires linked with the results of elemental composition of hair enables to understand better the mechanisms and factors influencing incorporation of elements to hair and consequently improves the interpretation of the results.