Assessment of hair and bone accumulation of beryllium by mice exposed to contaminated dusts

Abstract

This study looks at the accumulation of Be in the hair and bones of mice to understand both the use of hair as a bioindicator of exposure to Be and accumulation in bones as a means to evaluate the translocation of Be. We exposed two groups of mice (C3H/HeJ) to 250 microg m(-3) of two different particles sizes of Be metal (fine and intermediate; Be-F and Be-I) during 3 weeks of nose-only inhalation exposure. A control group was exposed to HEPA-filtered air. Mice were sacrificed either 1 or 3 weeks after the end of exposure. Mice were shaved and the bones were extracted. For washed hair, the results of mice sacrificed one week after the end of exposure were 8.3 + or - 1.4 microg kg(-1) hair for the control group, 114 + or - 42 microg kg(-1 )hair for the Be-I group, and 159 + or - 65 microg kg(-1) hair for the Be-F group. Results for Be-F mice sacrificed 3 weeks after the end of exposure showed an average Be concentration in washed hair of 419 + or - 100 microg kg(-1), thus suggesting that excretion of Be in hair increases with time. Be concentration in bones was 6 + or - 3 microg kg(-1) dry bone tissues for the control group, compared with 24 + or - 7 microg kg(-1) for Be-I and 34 + or - 6 or 43 + or - 8 microg kg(-1) for Be-F in mice sacrificed 1 or 3 weeks after the end of exposure. These results demonstrate the potential of using hair and bone as bioindicators of Be exposure.