First National Report of Blood Lead Levels in Mexican Children: An Analysis to Inform Public Health Actions and Policy

Abstract

Background. The toxic effect of lead has been documented in Mexico since 1878. Lead-Glazed Ceramics (LGC) for food consumption has been identified as the main source of exposure; however, it is not clear its contribution to blood lead levels (BLL) at the population level. To date, there is no monitoring system in Mexico. The aim of this study is to estimate the prevalence of high BLL in Mexican children and its association with LGC use, and identify states where prevention efforts should be focused. Methods. Capillary BLL was measured in 1-4 year old children from the National Health and Nutrition Survey (ENSANUT) 2018. Logit models were used to estimate the association between high BLL (≥5µg/dL) and LGC use, adjusted by sociodemographic characteristics. Results. BLL were measured in 4,713 children, representing 7.4 million. The national prevalence of high BLL is 17.3% (CI:14.8,20.0). According to high BLL prevalence and LGC use, we classified the 32 states in four groups: Twelve states with low prevalence (5.0%,CI:3.8,6.3), low frequent-use of LGC (3.9%) and high significant association (OR=8.34, p<0.00). Six states with a high prevalence (16.4%,CI:12.9,19.9), the highest frequent-use of LGC (21.4%) and the highest significant association (OR=10.47, p<0.00), being LGC the main source of exposure. Ten states with the highest prevalence (26.5%,CI:21.1,31.8), medium frequent-use of LGC (15.2%) and high significant association (OR=2.75, p<0.00), suggesting LGC as an important source along with other sources. Four states with high prevalence (13.6%,CI:7.6,19.6), but low frequent-use of LGC (5.0%) and no association (OR=0.33,p=0.26), discarding LGC and pointing to unknown sources of exposure. Conclusions. This study provides evidence of the magnitude and geographic distribution of high BLL in Mexico, confirms LGC use as an important source of exposure, and identifies states with other sources. These findings will be key to design the recently approved National Lead Exposure Control Program.