The reference value of blood lead level among the general adult population of eastern Iran.

The aim of this study to the estimate the lead concentrations in the blood of the adult population in South Khorasan Province, evaluate factors related to high lead blood concentrations and establish lead reference values (RVs) in our study population. In cross-sectional study, 400 people who lived in the province of South Khorasan in 2017 were selected. Demographic information was collected and clinical examinations were performed. As the geometric means, blood lead concentration (BLC) was expressed, 10th, 50th, 90th, and 95th percentiles, and 95% confidence intervals (CI) of the 95th percentile. The upper limits rounded values of the 95% CI with the 95th percentile were applied to calculate RVs. Mean BLC was 6.02 ± 7.41 µg dL, median of BLC was 4.4 µg dL (IQR: 2.9-6.5; range 0.9-54.7 µg dL). One hundred and twenty-five (31.2%) participants had BLCs between 5 and 10.0 µg dL, 40 (10.0%) between 10 and 20.0 µg dL, and 15 (3.8%%) over 20 µg dL. The RVs for BLC for men and women were 16 [95% CI: 10.13-15.96] µg dL and 15 [95% CI: 9.81-14.45] µg dL, respectively. Higher BLCs were significantly associated with age, gender, hemoglobin, white blood cell count, and serum phosphorus concentration. This bio-monitoring study of BLCs in the general population of South Khorasan Province offers important demographic and lifestyle factors-stratified reference data. It is essential to continue efforts to reduce lead exposure.