Project Number: WVA00094
CRIS Number: 0008428
PRELIMINARY INVESTIGATIONS IN SOILS
Investigators: Bhumbla, D. K.
Performing Department: Plant & Soil Sciences -- 1825
Start Date: 01/01/1989
Termination Date: 12/31/2006
Reporting period: 01/01/2001 to 12/31/2001
Progress Report:
Lead is most common trace element contaminant in soils of the USA. Anthropogenic atmospheric additions of trace elements have resulted in long-term accumulation of lead and other metals on forest soils of the northeastern USA. Trace metals in forest soils are readily complexed by humic substances, and their movement in soils is related to co-transport with dissolved organic matter. Several studies have documented increase lead concentration in organic soil horizons. Lead makes strong bonds with soil organic matter and so; it does not leach into surface or ground water. Lead in acidic mineral soil horizons can become a chronic source of lead in surface and subsurface waters. No information is available on lead distribution in organic and mineral horizons of forest soils of West Virginia that did not receive any direct additions of lead other than those from atmospheric additions. The objective of our research was to determine the pattern of Pb distribution in four forested soil series in West Virginia, remote from industrial sources of atmospheric metals, but subject to regional metal pollution from atmospheric deposition. Sixteen profiles from four soil series were sampled and soil samples were collected from each organic and mineral horizon. Soil samples were collected with plastic tools. Soil samples were analyzed for total and potentially available trace elements. Lead concentrations in organic layers were up to fifty times higher than those observed in mineral horizons. At most sites lead concentrations in leaf litter in surface soil layers were significantly lower than those observe in Oa and Oe soil horizons. Lower Pb concentrations in younger organic soil horizons than that in the older organic soil horizons shows that atmospheric additions to soil organic matter have declined due to switching from leaded gasoline to unleaded gasoline. However, in many soil profiles elevated levels of lead were observed in mineral soil horizons. Many of these forested soils have low soil clay and thus can potentially release Pb to leaching water.
Publications: (No publications.)
Impact:
Arsenic leaching from CCA treated wood into soil was observed and this has a potential to introduce arsenic into the food chain when vegetables are grown in raised beds constructed with CCA treated wood. Work is in progress on determining soil properties that govern arsenic uptake by plants.