Characterization and imaging of lead distribution in bones of lead-exposed birds by ICP-MS and LA-ICP-MS.

Lead (Pb) poisoning in raptors and water birds is a serious problem in many countries. However, only a small fraction of Pb poisoning has been detected in birds. Bone specimens may be useful indices of Pb exposure because bones contain ∼90% of the total Pb body burden. The original purpose of this study was to comprehensively analyze Pb accumulation in various bone types using inductively coupled plasma-mass spectrometry (ICP-MS). Since our results showed that Pb accumulation differed greatly depending on bone type, a secondary objective was defined, aiming to investigate the fine Pb distribution and its relation to bone structure and bone marrow by using laser ablation (LA)-ICP-MS. Our findings suggested that bone samples (1) consisting of trabecular tissue and (2) those that contain bone marrow could accumulate high levels of Pb following acute exposure. The shorter turnover time of trabecular bone can cause a rapid accumulation of Pb, and bone marrow may have an important role for internal exposure of Pb to bone tissue. Pb is accumulated in bones via blood flow, and bone marrow receives blood from outside the bones. In conclusion, bone samples provide valuable information on Pb exposure and could be useful to investigate and understand mortalities related to suspected Pb poisoning.