A biokinetic model to describe the distribution and excretion of arsenic by man following acute and chronic intakes of arsenite/arsenate compounds by ingestion

Abstract

<jats:p> An empirical mathematical model, comprising 17 compartments, has been produced to describe the biokinetics of ingested inorganic arsenic (As) in man — required to interpret bioassay data and to predict As tissue concentrations resulting from acute and chronic intakes of inorganic As. The rate constants used to describe the bi-directional transfer of As between compartments were chosen to result in model outcomes that match published data on the distribution of As in tissues and on the retention and excretion of radioisotopes of As administered to human subjects. The model was deployed in acute and chronic intake modes to produce predictions of tissue concentrations and excretion levels. Under conditions of chronic daily intake (1 μg d<jats:sup>-1</jats:sup>) for 50 years predicted final tissue concentrations vary by a factor of ∼2. Highest concentrations are predicted to occur in skin and bone (∼230ng kg<jats:sup>-1</jats:sup>). Tissue concentrations in all tissues other than bone are predicted to reach equilibrium after ∼100 days, and at this time, the amount of As excreted in urine has also reached approximate equilibrium at 79% of the daily dietary intake. This level then remains relatively constant unless intake ceases when tissue levels of As fall rapidly. Data on organic and inorganic As concentrations in urine were used to predict inorganic As intake and average tissue content for the USA population. Predicted tissue concentrations ranged from 2.3 μg kg<jats:sup> -1</jats:sup> in skin to 1.1 μg kg<jats:sup>-1</jats:sup> in muscle for an average inorganic As intake of 9.3 μg d<jats:sup>-1</jats:sup>. </jats:p>

A pilot study: The importance of inter-individual differences in inorganic arsenic metabolism for birth weight outcome

“…We acknowledge the possibility for attenuation bias (Sobus et al, 2010) in that it is possible that one biomarker measurement may not truly reflect variance over time within the individual; however most studies of iAs methylation do use a single urine and toenail sample to estimate exposure and to investigate various health outcomes (Ahsan et al, 2007; Heck et al, 2009; Steinmaus et al, 2010). Moreover, our study takes advantage of long-standing residence status and stable Romanian ground water arsenic levels; taken together this stability supports long-standing metabolic equilibrium of iAs in both the primary tissues and body fluids (Adeyemi et al, 2010). …”

Chronic arsenic intoxication diagnostic score (CAsIDS)

“…To estimate the BAsL/SW in patients that do not present a circadian variation in urinary arsenic concentration, we use the urinary arsenic concentration to calculate the fraction of the arsenic retained in the bone according to the multicompartment model of the Middlesex University (Adeyemi et al, ). This model states that under conditions of chronic intake the concentrations of arsenic in the body reach equilibrium after 100 days – only bone continues to accumulate arsenic.…”

“…As to CAsE grading over time we start from the minimal time required for arsenic to reach equilibrium in the body compartments, as predicted by the Middlesex University multicompartment model (Adeyemi et al, ), and refer to the latency periods between the onset of CAsE and the clinical manifestation of CAsI as reported in a series of reports by Grobe (, , , ) where the latency time varied from 3 to 50 years (average: 26 years), depending on the level of CAsE (Table ).…”

“…These estimates indicate a 9-to 236-fold increase in annual anthropogenic arsenic emission in the next decades, based solely on the estimated arsenic content in known reserves of gold, coal and oil. (Adeyemi et al, 2010), and refer to the latency periods between the onset of CAsE and the clinical manifestation of CAsI as reported in a series of reports by Grobe (1976Grobe ( , 1977Grobe ( , 1980Grobe ( , 1982 where the latency time varied from 3 to 50 years (average: 26 years), depending on the level of CAsE (Table 1).…”

Arsenic and fasting blood glucose in the context of other drinking water chemicals: a cross-sectional study in Bangladesh

“…To do the spatial data merge and exposure assignment, we used administrative shapefiles for Bangladesh from DIVA-GIS [16]. We extracted the GPS locations of the BDHS clusters and BGS-DPHE wells, then imported and projected these in ArcGIS 10.4.1 using the UTM 1984 45 N projection system.…”