Arsenic Speciation, Distribution, and Bioaccessibility in Shrews and Their Food

Abstract

Shrews (Sorex cinereus) collected at a historic mine in Nova Scotia, Canada, had approximately twice the arsenic body burden and 100 times greater daily intake of arsenic compared with shrews from a nearby uncontaminated background site. Shrews store arsenic as inorganic and simple methylated arsenicals. Much of the arsenic associated with their primary food source, i.e., small invertebrates, may be soil adsorbed to their exoskeletons. A physiologically based extraction test estimated that 47 ± 2% of invertebrate arsenic is bioaccessible in the shrew gastrointestinal tract. Overall, shrews appear to be efficient at processing and excreting inorganic arsenic.

Implications of in vitro bioaccessibility differences for the assessment of risks of metals to bats

“…Literature values for the diets of 14 United Kingdom bat species were used to identify the main insect orders that bats feed on (; Supplemental Data, Table S2). The bat diet data are expressed in percentage volume of a given prey taxa in all fecal pellets analyzed, which is the commonly used method for characterizing dietary composition .…”

“…The intestinal phase P2 was started by adjusting the pH of the samples to 7 with Na 2 CO 3 solution. Bile extracts, pancreatin , and chitinase were added to the sample solutions. The mixture was incubated and shaken at 275 rpm in a controlled temperature shaker for a further 4 h. Next, the samples were centrifuged for 10 min at 3661 g to separate the chyme and the digested matrix and were filtered with 0.45 μm syringe filter .…”

“…Bile extracts, pancreatin , and chitinase were added to the sample solutions. The mixture was incubated and shaken at 275 rpm in a controlled temperature shaker for a further 4 h. Next, the samples were centrifuged for 10 min at 3661 g to separate the chyme and the digested matrix and were filtered with 0.45 μm syringe filter . Negative and positive controls were run to assess the enzyme activity during the digestion process (further details in Supplemental Data).…”

Bioavailability, Bioaccesibility of Heavy Metal Elements and Speciation of as in Contaminated Areas of Chile

“…It is also recognized that inorganic arsenic are probably the most dangerous forms of arsenic in food, being As (III) more toxic than As (V) [18]. The formation of As (III) from the As (V) species present in natural environmental conditions, obeys in some case to an initial reduction before the methylation or other bigger species formation (arsenobetain, arsenosugar, etc.…”

Assessing the Bioavailability and Bioaccessibility of Total Arsenic and Arsenic Species in Environmental Samples

“…A way to quantify the absorbable fraction in trace element bioaccessibility is the "in vitro" simulation of digestion processes 15 . It is also recognized that inorganic arsenic are probably the most dangerous forms of arsenic in food, being As (III) more toxic than As(V) 16 . The formation of As (III) from the As(V) species present in natural environmental conditions, obeys in some case to an a initial reduction before the methylation or other bigger species formation (arsenobetain, arsenosugar, etc.…”