Human biomonitoring reference values for metals and trace elements in blood and urine derived from the Canadian Health Measures Survey 2007-2013.

Human biomonitoring reference values are statistical estimates that indicate the upper margin of background exposure to a given chemical at a given time. Nationally representative human biomonitoring data on 176 chemicals, including several metals and trace elements, are available in Canada from 2007 to 2013 through the Canadian Health Measures Survey (CHMS). In this work, we used a systematic approach based on the reference interval concept proposed by the International Federation of Clinical Chemistry and Laboratory Medicine and the International Union of Pure and Applied Chemistry to derive reference values (RVs) for metals and trace elements. These RVs were derived for blood and urine matrices in the general Canadian population based on the latest biomonitoring data from the CHMS. Biomarkers were chosen based on specific selection criteria, including widespread detection in Canadians (≥66% detection rate). Reference populations were created for each biomarker by applying appropriate exclusion criteria. Age and sex were evaluated as possible partitioning criteria and separate RVs were derived for the sub-populations in cases where partitioning was deemed necessary. The RVs for metals and trace elements in blood ranged from 0.18μg/L for cadmium in young children aged 3-5 years to 7900μg/L for zinc in males aged 20-79 years. In the case of urinary biomarkers, the RVs ranged from 0.17μg/L for antimony in the total population aged 3-79 years to 1400mg/L for fluoride in adults aged 20-79 years. These RVs represent the first set of reference values for metals and trace elements in the general Canadian population. We compare the RVs from other countries where available and discuss factors that could influence such comparisons.