Microbiology and Environmental Toxicology Department, University of California, Santa Cruz, California 95064, USA.
Environ Sci Technol. 2010 Apr 1;44(7):2639-47. doi: 10.1021/es903176w.
Lead poisoning is a primary factor impeding the survival and recovery of the critically endangered California Condor (Gymnogyps californianus). However, the frequency and magnitude of lead exposure in condors is not well-known in part because most blood lead monitoring occurs biannually, and biannual blood samples capture only approximately 10% of a bird's annual exposure history. We investigated the use of growing feathers from free-flying condors in California to establish a bird's lead exposure history. We show that lead concentration and stable lead isotopic composition analyses of sequential feather sections and concurrently collected blood samples provided a comprehensive history of lead exposure over the 2-4 month period of feather growth. Feather analyses identified exposure events not evident from blood monitoring efforts, and by fitting an empirically derived timeline to actively growing feathers, we were able to estimate the time frame for specific lead exposure events. Our results demonstrate the utility of using sequentially sampled feathers to reconstruct lead exposure history. Since exposure risk in individuals is one determinant of population health, our findings should increase the understanding of population-level effects from lead poisoning in condors; this information may also be helpful for other avian species potentially impacted by lead poisoning.
铅中毒是严重威胁加利福尼亚秃鹫（Gymnogyps californianus）生存和恢复的主要因素。然而，秃鹫体内铅暴露的频率和程度尚不清楚，部分原因是大多数血液铅监测是每半年进行一次，而半年一次的血液样本仅捕获了鸟类每年暴露史的约 10%。我们研究了利用加利福尼亚自由飞翔的秃鹫的生长羽毛来建立鸟类的铅暴露史。我们表明，对连续羽毛段和同时采集的血液样本进行的铅浓度和稳定的铅同位素组成分析，提供了在羽毛生长的 2-4 个月期间的全面铅暴露史。羽毛分析确定了血液监测工作中没有明显的暴露事件，并且通过将经验推导的时间线拟合到正在生长的羽毛上，我们能够估计特定铅暴露事件的时间框架。我们的研究结果证明了使用顺序取样的羽毛来重建铅暴露史的有效性。由于个体的暴露风险是种群健康的决定因素之一，因此我们的发现应该提高对秃鹫铅中毒的种群水平影响的认识；这些信息对于其他可能受到铅中毒影响的鸟类物种也可能有帮助。
