June 16, 2010
Bone samples could be the ultimate biomarker for environmental pollution
Exposure to chemical pollutants is of growing concern to regulators, health workers, and environmentalist groups alike. Now, researchers in the US and Russia have demonstrated that samples of human bone can act as a biological marker for dozens of metals and toxic elements across the periodic table. They describe details in a study published in the International Journal of Environment and Health.
Of the 92 natural chemical elements in the periodic table, not counting those from which human tissues are mainly composed, including carbon, hydrogen, oxygen, and nitrogen, the team demonstrated the presence of 44 additional elements. Among them are toxic elements, such as aluminum, arsenic, samarium and thallium, as well as the trace elements necessary for life, including calcium, iron, magnesium, and phosphorus.
"Bone is a tissue in which the turnover of these elements, particularly those that have an affinity for bone, is extremely slow and their biological half-lives are estimated to be from few years to decades," the team explains. "This gives bone several important features as a subject of environmental monitoring."
The amount of any particular element in bone at a given time correlates with a person's intake or exposure to that element over a period of years. For elements with a strong affinity for bone, then accumulation is higher than in other tissues and so can reveal even low-level exposure after a long period. Moreover, given that the skeleton constitutes much of our body mass, the element level in bone may reflect total body content. "Bone is therefore a suitable index medium for evaluation of low-level and long-term exposure and the body burden of toxic bone-seeking elements," the team adds.
The current research paper provides a base line for bone analysis of a wide range of elements that might now be monitored in terms of environmental and dietary exposure in which gender, age, domicile and other factors are taken into account.
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