The Time Trend of Blood Lead and Cadmium Levels in Rural Chinese Children: China Nutrition and Health Survey 2002 and...

Area of Science:

• Environmental Health
• Pediatric Toxicology
• Public Health Surveillance

Background:

• Childhood exposure to heavy metals like lead (Pb) and cadmium (Cd) poses significant health risks.
• Understanding temporal trends in blood Pb and Cd levels is essential for assessing public health interventions in vulnerable populations.

Purpose of the Study:

• To investigate the time trend of blood lead (Pb) and cadmium (Cd) levels in rural Chinese children.
• To analyze changes in the prevalence of elevated blood Pb and Cd concentrations and their reference values over a decade.

Main Methods:

• Utilized data from the China Nutrition and Health Survey (CNHS) in 2002 and 2012, involving 1698 and 1581 children, respectively.
• Measured blood Pb and Cd concentrations using inductively coupled plasma mass spectrometry (ICP-MS).
• Calculated prevalence rates for blood Pb levels >5 µg/dL and blood Cd levels >0.5 µg/L, along with 95th percentile reference values (RV95s).

Main Results:

• Median blood Pb levels decreased from 6.3 to 3.1 µg/dL, and median blood Cd levels decreased from 0.64 to 0.39 µg/L between 2002 and 2012.
• Prevalence of elevated blood Pb (>5 µg/dL) dropped from 63.6% to 14.2%, and elevated blood Cd (>0.5 µg/L) decreased from 62.7% to 33.5%.
• RV95s for blood Pb and Cd also showed a declining trend, indicating reduced exposure across the population.

Conclusions:

• Blood Pb and Cd levels in rural Chinese children have significantly improved over the 2002-2012 period.
• Despite improvements, the risks associated with Pb and Cd exposure remain a serious concern.
• Continuous health monitoring, evaluation, and collaborative efforts between government and society are necessary to mitigate exposure risks.