Speed‐mapping of arsenic distribution in the tissues of earthworms inhabiting arsenious soil.

Abstract

We have examined the distribution of arsenic in the metal-sequestering chloragogenous tissue of a population of the earthworm, Lumbricus rubellus, exposed to the metalloid in its natural environment. The localization technique was qualitative digital X-ray speed mapping (2 minute total acquisition time) offresh air dried tissue smears. Arsenic was located in association with sulphur in a discrete chloragocytic compartment; it was not detected in the phosphate-rich chloragosome granules. In earthworm tissues arsenic was distributed according to its sulphydryl-seeking trivalent form, not as the phosphate-resembling pentavalent form.

Earthworms as agents for arsenic transport and transformation in roxarsone-impacted soil mesocosms: A µXANES and modeling study

“…XANES spectra collected from the earthworm cross-section suggest that As within the earthworm has been reduced to As(III) and bound to glutathione in agreement with previous studies (Morgan et al, 1994;Langdon et al, 2002Langdon et al, , 2005. Extracts of earthworms have shown the presence of organoarsenic compounds such as arsenobetaine, DMA(V), and MMA, along with multiple arsenosugars (Geiszinger et al, 1998(Geiszinger et al, , 2002.…”

Arsenic biotransformation in earthworms from contaminated soils

“…The resistance is more likely due to a second process (Fig. 2, c) whereby As is thought to be sequestered via binding with sulphur-rich metallothionein within the chloragogenous tissue 3,17,31 allowing the continued 15 accumulation of inorganic As (Fig. 3a) in a form that is not biologically reactive 6 .…”

Derivation of ecotoxicologically based soil quality criteria for arsenic

“…In einem zweitem Experiment nahmen die LCs0 fiber 4 d mit Ver~inderung der Bodentextur yon Lehm nach Sand, mit Zunahme des Boden-pH und Abnahme des Humusgehahes von 280 mg As/kg auf 60 mg As/kg ab. Morgan et al (1994) In der Literatur ist nur eine NOEC aus l~ingerfristigen Tests an subletalen Parametern fOr Bodeninvertebraten belegt (--~ Tabelle 1). Dieser NOEC von 48 mg As/kg Boden TG, den Fischer 8, Kozorus (1992) fOr Eisenia foetida ermittelt haben, und der NOEC-Wert ftir die Mortalit~it tiber 4 d von 50 mg As/kg bzw.…”

“…Ausnahmen yon diesem Verteilungsmuster stellen BGden dar, die mit arsenhaltigen Pflanzenschutzmitteln kontaminiert sind (MEHARG et al, 1998). In schlecht oder nicht beliifteten BGden ist As(Ill) die vorherrschende Oxidationsstufe (HAMASAKI et al, 1995;MEHARG et al, 1998 & KEENEu 1975;MORGAN et al, 1994). In verschiedenen Studien wurde beobachtet, dass die Oxidationsstufe die HGhe der Toxizidit beeinflusst.…”