Association between total ingested arsenic and toenail arsenic concentrations

Area of Science:

• Environmental Health
• Toxicology
• Biomonitoring

Background:

• Arsenic exposure from drinking water shows non-linear associations with toenail arsenic at low levels.
• This nonlinearity may stem from exposure misclassification.
• Dietary intake is a potential, often overlooked, contributor to overall arsenic burden.

Purpose of the Study:

• To investigate the contribution of dietary arsenic intake to toenail arsenic concentrations.
• To assess potential exposure misclassification in arsenic biomonitoring studies.
• To evaluate the combined impact of water and food arsenic on internal dose.

Main Methods:

• A duplicate diet study was conducted over 6 days with 47 women in Pabna, Bangladesh.
• Total inorganic arsenic in food samples was measured using ICP-DRC-MS.
• Multivariate regression models analyzed the association between dietary intake, water arsenic, and toenail arsenic.

Main Results:

• Median daily arsenic intake from food was 48.3 µg/day and from drinking water was 4.2 µg/day.
• Dietary intake (1.0 µg/kg-day) contributed more to the median daily arsenic dose than drinking water (0.1 µg/kg-day).
• Total daily arsenic intake from both food and drinking water explained 71% of the variability in toenail arsenic concentrations.

Conclusions:

• Both dietary intake and drinking water are significant contributors to internal arsenic dose, as indicated by toenail arsenic concentrations.
• Dietary arsenic exposure should be considered in biomonitoring studies to avoid misclassification.
• Understanding total arsenic exposure from multiple sources is crucial for accurate risk assessment.