The development of reference values of trace elements is recognized as a fundamental prerequisite for the assessment of trace element nutritional status and health risks. In this study, a total of 1400 pregnant women aged 27.0 ± 4.5 years were randomly selected from the China Nutrition and Health Survey 2010–2012 (CNHS 2010–2012). The concentrations of 14 serum trace elements were determined by high-resolution inductively coupled plasma mass spectrometry. Reference values were calculated covering the central 95% reference intervals (P2.5–P97.5) after excluding outliers by Dixon’s test. The overall reference values of serum trace elements were 131.5 (55.8-265.0 μg/dL for iron (Fe), 195.5 (107.0–362.4) μg/dL for copper (Cu), 74.0 (51.8–111.3) μg/dL for zinc (Zn), 22.3 (14.0–62.0) μg/dL for rubidium (Rb), 72.2 (39.9–111.6) μg/L for selenium (Se), 45.9 (23.8-104.3) μg/L for strontium (Sr), 1.8 (1.2–3.6) μg/L for molybdenum (Mo), 2.4 (1.2–8.4) μg/L for manganese (Mn), 1.9 (0.6–9.0) ng/L for lead (Pb), 1.1 (0.3-5.6) ng/L for arsenic (As), 835.6 (219.8–4287.7) ng/L for chromium (Cr), 337.9 (57.0–1130.0) ng/L for cobalt (Co), 193.2 (23.6–2323.1) ng/L for vanadium (V), and 133.7 (72.1–595.1) ng/L for cadmium (Cd). Furthermore, some significant differences in serum trace element reference values were observed between different groupings of age intervals, residences, anthropometric status, and duration of pregnancy. We found that serum Fe, Zn, and Se concentrations significantly decreased, whereas serum Cu, Sr, and Co concentrations elevated progressively compared with reference values of 14 serum trace elements in pregnant Chinese women. The reference values of serum trace elements established could play a key role in the following nutritional status and health risk assessment.

Lead (Pb) pollution is a global public health problem and adversely affects children health across a wide range of exposure levels. This study was conducted to evaluate the blood Pb levels (BLLs) of Chinese urban children aged 6−11 years and to describe the temporal variations from the China Nutrition and Health Survey (CNHS) in 2002 and 2012. A total of 2182 (1036vs.1146) Chinese urban children were selected in the CNHS 2002 and the CNHS 2012 using the multistage stratified cluster random and probability proportional to size sampling method. The BLLs of urban children were determined using inductively coupled plasma mass spectrometer (ICP-MS), whilst the prevalence of BLLs >50 µg/L and >100 µg/L were calculated, as well as the reference values (RV₉₅s: the upper limit of 95% confidence interval of 95th percentile). From the CNHS 2002 to the CNHS 2021, the median BLLs of Chinese urban children had obviously changed from 67.4 µg/L to 36.9 µg/L, and the RV₉₅s of BLLs had also descrended from 149.1 µg/L to 107.9 µg/L. In addition, the prevalence of BLLs with >50 µg/L and >100 µg/L had markedly decreased from 74.0% and 18.2% in the CNHS 2002 to 28.4% and 5.2% in the CNHS 2021. In conclusion, the BLLs of Chinese urban children had been definitely improved in the past 10 years. However, the findings of our study suggested that it is imperative to implement the monitoring and evaluating and to continue control Pb exposure.