Environmental Biogeochemistry of Lead

The long-term uses of lead explain why this element should be so widely dispersed in the environment. In this relation we should answer the question as to what is the natural background level of lead. At present this is a question of controversy. Lead levels in modern people are frequently 10% of the toxic level. Some analyses of ancient bones and ancient ice cores seems to suggest that this relatively high level is not new and has been existed in the environment. Accordingly, the assumption was carried out that life has evolved in the presence of this toxic element. 

Similar data reported on the content of lead in the meticulously preserved old skeleton contain 0.01 to 0.001 times as much lead as contemporary skeleton. 

A different perspective is provided in the analysis of pre-industrial and contemporary Alaskan Sea otter skeletons. The total concentrations of lead in the two groups of skeletons were similar, but their isotopic compositions were different. The preindustrial skeletons contained lead with an isotopic ratio corresponding to natural deposits in the region, while the ratio in the contemporary ones was characteristic of industrial lead from elsewhere (Smith et al, 1990). 

The most important source of lead transport is connected with air emission, transportation and deposition. Among the other metals, lead emissions are most uniformly 

The most emissions were monitored in UK, northern parts of France, the Netherlands and Germany, southern Ukraine and central Russia. The northeastern part of Russia and northern parts of Scandinavia have had the lowest emissions. 

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However, not all of the lead currently in the environment is in a natural state. Lead s usefulness and natural abundance have led to its current position as a ubiquitous pollutant Some 300 million tons of Pb from anthropogenic sources is currently dispersed worldwide (Fig. 4 and Table XIV) (5, 10, 18, 23, 357, 358). Here, we discuss the properties of some of the major minerals of lead and then mrn to a discussion of anthropogenic lead in soil, water, and air. For a more in-depth discussion, the reader is directed to several books that discuss the environmental biogeochemistry of lead in greater detail (3, 47, 359, 360). 

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