Speciation and Vertical Distribution of Lead and Lead Shot in Soil at a Recreational Firing Range

Abstract

In this study, the speciation, vertical distribution and soil particle size fractions of lead in soil samples at a recreational firing range was determined. This study was performed to gain a better understanding of how lead shot breaks down at ranges. Both the chemical form of lead and the types of soil particles with which lead is associated are important for understanding not only the mobility and persistence, but also the human and ecological impact of lead at these ranges. Lead as shot gun pellets was found to be the dominant form of lead in soil samples. The highest levels were measured in surface samples located in the “fall zone” of the range. Results indicate shot to be relatively absent below surficial samples. Lead concentrations in soil decreased markedly across a 0–6″ depth profile. Lead carbonates were the dominant non-shot form of lead present at all depths. Water-soluble lead species made up a minor fraction of the non-shot lead present in the samples. Based on soil particle sizes measured, highest concentrations of lead were measured in soil particles passing a 0.075 mm sieve.

Keywords:

• Lead
• soil contamination
• recreational firing ranges
• lead mobility and persistence
• lead speciation

Acknowledgements

The authors acknowledge Francis A. Sagan, Wentworth Institute of Technology, Class of 1930.