Collaborative Research: Collaborative Research: Anthropogenic Impact on the Geochemical Cycle of Lead (Pb) since the Industrial Revolution in Asia

铅（Pb）是一种毒性很强的重金属，对儿童的发育和行为有不可逆的影响，对成年人也有一定的健康影响。尽管铅已经被使用了几千年，但直到工业革命以及后来在20世纪20年代含铅汽油在欧洲和北美引入时，人类活动产生的铅才超过其自然和工业化前的贡献约两个数量级。自20世纪70年代以来，随着排放控制措施的引入和含铅汽油的逐步淘汰，北美和欧洲的人为铅排放量有所减少。然而，亚洲的情况并非如此。极地和高海拔冰川保存了气候和环境变化的记录，因此可以研究过去和现在的大气铅水平。该项目将确定西藏和喜马拉雅山冰芯中铅的来源。它将为政策制定者提供信息，以制定减少铅排放的战略。研究结果将通过本科生和研究生的课堂以及外联活动向公众分享。为了了解人类活动对亚洲从工业化前到现在的铅地球化学循环的作用，亚洲地区目前正在经历一些剧烈的环境变化，研究很少，三个不同地点的冰芯中铅的同位素组成，西藏西北部的古力亚冰帽、中部的普若岗日冰帽和喜马拉雅山脉的达索普冰川将得到重建。Pb同位素比值的研究有助于：（1）建立亚洲工业革命前的Pb同位素背景，（2）确定工业革命后人类活动对亚洲Pb地球化学循环的影响;以及（3）评估北美人类活动产生的铅是否已经到达亚洲。该奖项反映了NSF的法定使命，并通过评估被认为值得支持使用基金会的知识价值和更广泛的影响审查标准。

Lead (Pb) is a highly toxic heavy metal with negative and irreversible effects on children’s development and behavior, and also with a number of health effects in adults. Even though Pb has been used for millennia, it was not until the Industrial Revolution and later when leaded gasoline was introduced in Europe and North America in the 1920s that Pb from human activities surpassed its natural and preindustrial contribution by about two orders of magnitude. Anthropogenic Pb emissions have decreased in North America and Europe since the 1970s with the introduction of emission controls and after leaded gasoline was phased out. However, this has not been the case in Asia. Polar and high-altitude glaciers preserve records of climate and environmental changes, and thus allow to study past and present atmospheric Pb levels. This project will determine the sources of Pb found in ice cores from Tibet and the Himalayas. It will provide information to policy makers to develop strategies to reduce Pb emissions. The results will also be shared through classes at the undergraduate and graduate levels and to the general public by outreach activities.To understand the role of human activities on the Pb geochemical cycle from pre-industrial times to the present in Asia, a region that is currently undergoing a number of drastic environmental changes and is poorly studied, the isotopic composition of Pb in ice cores from three different sites, the Guliya ice cap in northwestern Tibet, the Puruogangri ice cap in central Tibet and the Dasuopu glacier in the Himalayas will be reconstructed. The Pb isotope ratios will allow: (1) the establishment of a pre-industrial Pb isotopic background in Asia; (2) the determination of how human activities have modified the Pb geochemical cycle after the Industrial Revolution in Asia; and (3) the assessment of whether Pb from human activities in North America have reached Asia.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.