US EPA

47675 

Journal Article 

Vertical distribution of lead and arsenic in soils contaminated with lead arsenate pesticide residues 

Peryea, FJ; Creger, TL 

1994 

1 

Water, Air, and Soil Pollution
ISSN: 0049-6979
EISSN: 1573-2932 

BIOSIS/95/07124 

78 

3-4 

297-306 

English 

10.1007/BF00483038 

WOS:A1994QD65800006 

http://www.springerlink.com/index/10.1007/BF00483038
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Many deciduous fruit tree orchard sites throughout the world are contaminated with lead (Pb) and arsenic (As) from past use of lead arsenate insecticides. The vertical distribution of Pb and As was examined in six contaminated orchard soils in the State of Washington, USA. Most of the Pb and As was restricted to the uer 40 cm of soil, with Pb concentration maxima ranging from 2.15 to 10.69 mmol/kg, and As concentration maxima ranging from 0.77 to 4.85 mmol/kg. In all cases, there were lower Pb and As concentrations at the soil surface than deeper in the profile. Arsenic was depleted relative to Pb in the topsoils and was enriched relative to Pb in the subsoils, suggesting that there has been preferential movement of As. Absolute soil enrichment with Pb occurred to depths between 15 and 50 cm. Absolute soil enrichment with As occurred to depths between 45 and > 120 cm. At 120 cm, Pb concentrations were < 0.05 mmol/kg, and As concentrations ranged from 0.07 to 0.63 mmol/kg. The deeper movement of Pb and As in the study soils relative to that reported for lead arsenate-contaminated soils elsewhere is attributed to high loading rates of lead arsenate, coarse soil texture, low organic matter content, and use of irrigation. The results indicate that Pb and As concentrations in lead arsenate-contaminated soils are high enough to be of potential environmental concern. The amount of As redistribution appears to be substantial enough to preclude some methods of remediation and to create potential risk of contamination of underlying shallow groundwater. 

ORCHARD SOILS