Health Risk Assessment of Dietary Arsenic Exposure and Selenium Deficiency in Tibet Based on In Vitro...

Area of Science:

• Environmental Science
• Toxicology
• Human Health

Background:

• The Tibetan Plateau exhibits a unique high-arsenic (As) and low-selenium (Se) geochemical background.
• This geochemistry can transfer to humans through diet, posing significant health risks.
• Traditional exposure assessments using total elemental concentrations may overlook bioavailable fractions during digestion.

Purpose of the Study:

• To evaluate dietary As exposure and Se intake in Tibetan populations.
• To assess the impact of bioaccessibility on risk and intake estimations.
• To investigate the As-Se relationship post-gastrointestinal digestion.

Main Methods:

• Utilized the Unified Bioaccessibility Method (UBM) combined with Monte Carlo simulation.
• Analyzed typical Tibetan foods for As and Se content and bioaccessibility.
• Modeled dietary exposure and intake across different age groups.

Main Results:

• A low dietary Se/As ratio (0.80) was found, significantly below the national average (4.35).
• Bioaccessibility-adjusted modeling indicated persistent carcinogenic risks from As exposure above 10⁻⁴ for all ages, highest in children.
• Estimated Se intake remained below recommended levels, suggesting deficiency.

Conclusions:

• Incorporating bioaccessibility into dietary exposure assessments is crucial for accurate risk evaluation.
• Tibetan populations face a dual burden of high As-related health risks and inadequate Se intake.
• Further public health interventions are needed to mitigate these risks and improve nutritional status.