PARENT SESSION
PM9 - Arsenic Fate & Effects
Monday, 18 November 2002
8:00 AM to 6:30 PM
Exhibit Hall

(P295) Maternal transfer of arsenic in black-tailed gull (Larus crassirostris) and Dall's porpoise (Phocoenoides dalli).

Kubota, Reiji^*,1, Kunito, Takashi¹, Tanabe, Shinsuke¹, Yang, Jian², Miyazaki, Nobuyuki², Ogi, Haruo³, Shibata, Yasuyuki⁴, ¹ Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama² Otsuchi Marine Research Center, Ocean Research Institute, The University of Tokyo, Otsuchi³ Faculty of Fisheries, Hokkaido University, Hakodate⁴ National Institute for Environmental Studies (NIES), Tsukuba

ABSTRACT- Arsenic exists in various organic and inorganic chemical forms in the environment and in organisms. Because metabolism and toxicity of arsenicals depend on their chemical forms, chemical speciation of arsenic is needed for their evaluation. Many studies have dealt with arsenic accumulation in lower trophic marine animals. However, little is known about levels, chemical forms, and species-specific accumulation of arsenic in higher trophic marine animals and also no investigation has been conducted on wild birds. Furthermore, there are no data on maternal transfer of arsenic species to fetus or egg in wildlife. In this study, concentrations of total arsenic and individual arsenic compounds in several tissues and eggs of black-tailed gulls and in liver, kidney, and muscle of Dalls porpoise (mother and fetus) were determined to understand the chemical forms of arsenic in the tissues and to characterize maternal transfer of arsenic compounds to eggs and fetus, respectively. Relatively high concentrations of arsenic were observed in the liver, kidney, pancreas, muscle and gonad of black-tailed gull. For a mother bird that laid three eggs, the eggs comprised 11.3% of arsenic burden and this value was lower than their weight percentage (32.0%). Hence, it seems that transfer of arsenic to egg might be controlled by some physiological processes in black-tailed gull. Chemical speciation of arsenic revealed that arsenobetaine was the major arsenic compound in all the tissues of black-tailed gull and Dalls porpoise. Dimethylarsinic acid, methylarsonic acid, arsenocholine, and an unidentified arsenic compound were also detected as minor constituents in the animals. Like maternal tissues, eggs and fetus also contained arsenobetaine and dimethylarsinic acid. These results suggest that arsenobetaine and dimethylarsinic acid can be transferred from mother to eggs and fetus.

Key words: arsenic, chemical speciation, maternal transfer, marine mammal