Uptake of Aromatic Arsenicals from Soil Contaminated with Diphenylarsinic Acid by Rice

Abstract

Chemical warfare agents containing aromatic arsenicals (AAs) such as Clark I (diphenylchloroarsine) are well-known, as is the risk of leakage from such munitions into the environment. We investigated the uptake of AAs in agricultural soils by rice. Methylphenylarsinic acid (MPAA) was detected in brown rice grown in contaminated soil. Dimethylphenylarsine oxide (DMPAO) and methyldiphenylarsine oxide (MDPAO) were detected in the straw but not in the grains grown in the contaminated soil. Inthe contaminated soil, phenylarsonic acid (PAA) and MPAA concentrations decreased and DMPAO concentration increased under the flooded conditions; however, their concentrations remained unchanged underthe upland conditions. DMPAO was detected in the straw of the rice grown in PAA- or MPAA-amended soil but was not detected in that grown in a PAA- or MPAA-added solution culture. MDPAO was detected in the straw of the rice grown in diphenylarsinic acid (DPAA)-amended soil but was not detected in that grown in a DPAA-added solution culture. Thus, MPAA and DPAA were methylated not in the rice plant but in the soil under the flooded conditions. Dephenylated products were detected in the straw grown in AA-added solution cultures, but demethylated products were not detected. DMPAO and MDPAO absorbed by the shoots were retained, and MPAA and DPAA absorbed by the shoots were translocated to the grains more easily than other AAs.

Adsorption and desorption characteristics of diphenylarsenicals in two contrasting soils

“…Aromatic arsenicals (AAs) were once used for the manufacture of chemical weapons such as Clark I (diphenylchloroarsine) and Clark II (diphenylcyanoarsine) which were employed as vomiting and sneezing agents during both World Wars (Arao et al, 2009). After the Second World War chemical weapons were buried and dumped in several parts of China (Wada et al, 2006), Japan Ishizaki et al, 2005), Germany (Hempel et al, 2009), and Belgium (Bausinger and Preuss, 2005).…”

Solid-solution partitioning and thionation of diphenylarsinic acid in a flooded soil under the impact of sulfate and iron reduction

“…Numerous studies have reported the presence of DPAA in contaminated soil and groundwater samples with a history of warfare Daus et al, 2008). Such DPAA contamination can pose a threat to water quality and human health Arao et al, 2009). For example, in vitro cytotoxic and genotoxic effects of DPAA have been demonstrated (Ochi et al, 2004;Kroening et al, 2009).…”

“…Sulfide derived from microbial sulfate reduction can react directly with As to form soluble thioarsenate species or insoluble precipitates when substantial amounts of dissolved As and sulfide are present (Root et al, 2013;Stucker et al, 2014;Xu et al, 2011). Limited studies also show that DPAA can be rapidly dephenylated or methylated under flooded soil conditions (Maejima et al, 2011;Arao et al, 2009) and thionation is an important anaerobic pathway for DPAA under sulfate-reducing conditions (Guan et al, 2012;Hisatomi et al, 2013). However, the partitioning of DPAA in flooded soil was underestimated.…”

Simultaneous determination of diphenylarsinic and phenylarsinic acids in amended soils by optimized solvent extraction coupled to HPLC–MS/MS

“…Recently, diphenylarsinic acid (DPAA) and phenylarsinic acid (PAA) have increasingly gained attention due to their occurrence as chemical warfare agents at contaminated sites and their potential to generate public and environmental health concerns Nakamiya et al, 2013;Arao et al, 2009;Ochi et al, 2004). The main source of DPAA and PAA into the environment is aromatic arsenicals (AAs) such as Clark I (diphenylcyanoarsine) and Clark II (diphenychloroarsine), which were widely produced during World Wars I and II as chemical warfare agents.…”