Estimating arsenic biotransfer factors from feed to chicken: a viable approach to animal feed risk assessment

Abstract

Reliable biotransfer factor (BTF) data are critical for animal-feed studies in human risk assessment. A wide range of BTF values have been reported (0.0015–0.83 d/kg), expressed as the ratio of total arsenic (tAs) concentration (µg/kg) in chicken to daily intake rate (µg/d) of tAs in feed (tAs/tAs). Data on inorganic As (iAs) for chicken meat and tAs concentrations for feed were obtained from our related study. Using the linear regression technique developed in this study, we estimated the BTF as 0.016 d/kg, as iAs/tAs (R² > 0.7702) and 0.55 d/kg as tAs/tAs (R² =  0.9743) for whole chicken meat. From a mass-balance perspective, we suggest that tAs be used as the denominator for the BTF unit. To illustrate our feed-risk assessment method, we analyzed commercial feeds for tAs concentration (n = 79). Consumption data for the general population (n = 2479) were obtained from a Taiwanese total diet study. Bivariate Monte Carlo simulations (n = 10,000) showed that the 95^th percentile (P95) of estimated daily intake (EDI) was 0.002 µg/kg body weight (bw)/d as iAs (< the benchmark dose lower limit of 3.0 µg/kg bw/d). Our results thus show that the commercial chicken feeds assessed in this study are of low health concern for the general Taiwanese population. We discuss the factors that may have affected the assessment, such as the type of animals investigated, type of feeds, feed tested, type of chemical species used for BTF estimation and statistical approach.

Keywords:

• Arsenic
• biotransfer factor
• chicken-feed risk assessment
• human exposure assessment
• Monte Carlo simulation

Acknowledgements

This study was supported by the Taiwan Council of Agriculture, Executive Yuan (105AS-2.3.1-LI-L1). We thank the National Health Research Institutes (NHRI) for providing the 24-hour dietary recall data.

Disclosure statement

No potential conflict of interest was reported by the author(s). The authors declare that they have no known competing financial interests or personal relationships that may have influenced the work reported in this paper.

Additional information

Funding

This work was supported by Council of Agriculture (05AS-2.3.1-LI-L1).