We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Lead Concentrations, Isotope Ratios, and Source Apportionment in Road Deposited Sediments, Honolulu, Oahu, Hawaii.
- Authors
Sutherland, R. A.; Day, J. P.; Bussen, J. O.
- Abstract
Anthropogenic contributions of lead to the urban environment have been dominated by combustion of leaded gasoline. A number of studies have used lead concentrations in road deposited sediments (RDSs) to infer automobile contributions. However, few studies have combined concentration data, enrichment ratios, and lead isotope ratio data into a comprehensive picture of lead contamination of road sediments. An urban, non-industrialized basin, in Oahu, Hawaii, was selected for investigation. Twenty RDS samples were collected throughout the 11 km2 system, with an undisturbed soil profile sampled to a depth of 30 cm to document background lead levels. Median lead concentrations from a weak (cold) HCl digestion and a hot nitric acid digestion were 3 and 7 mg kg-1 for the background soil, and 256 and 303 mg kg-1 for RDSs. The median Pb enrichment ratio (HCl digestion) for RDSs was 129, with a range from 24 to 883. All the data collected point to a highly contaminated environment. Lead isotope ratios from potential sources were examined relative to those observed for RDSs in the system. Host geological rocks, paint, and long-range aerosol transport were ruled-out as significant sources based on an examination of isotope ratios and potential loadings to road sediments. Leaded gasoline was identified as the major contributor to present-day road sediments based on their radiogenic nature, with mean 206Pb/204Pb = 18.787 ± 0.096 (95% confidence interval), 207Pb/204Pb = 15.847± 0.074, 208Pb/204Pb = 38.836 ± 0.221, and 206Pb/207Pb = 1.184 ± 0.009. The contribution of gasoline additives to RDS for two periods, pre-1968 and post-1968, were estimated using 206Pb/207Pb ratios. The average contribution of post-1968 lead to RDSs was 59%, with a range from 32 to 81%. To explain the mixed age of lead in the RDSs, we suggest that erosional processes have mobilized sediment from roadside reservoirs in the basin that have accumulated automobile emissions primarily since the 1930s. The significant shift in use of radiogenic (J-type) ores, mostly from Missouri, USA, have allowed us to fingerprint and apportion lead in RDSs of this system.
- Subjects
LIQUID fuels; FECAL incontinence; NITRIC acid; INORGANIC acids; LEAD isotopes; SEDIMENT microbiology
- Publication
Water, Air & Soil Pollution, 2003, Vol 142, Issue 1-4, p165
- ISSN
0049-6979
- Publication type
Article
- DOI
10.1023/A:1022026612922