LINEAR ALKYLBENZENE SULFONATE (LAS) - UNEP Chemicals

OECD SIDS LINEAR ALKYLBENZENE SULFONATE (LAS)
(o)
Type of Measurement: Background [ ]; At contaminated site [ ]; Other [X] concentrations in
sludge-amended agricultural soils
Medium: soil
Method: An extensive monitoring study was performed on sludge-amended soils in
the Thames Water Authority area, UK, by a Soap and Detergent Industry
Association task force. A total of 51 fields from 24 farms were used, with
sites representing a range of soil types, frequency and level of sludge
applications, and agricultural uses. A total of 35 of the fields were pasture
lands and 16 fields were arable land. The majority of fields were surface
spread with primary and anaerobically digested sludge containing
approximately 4.5% dry solids.
Results: Forty two farm sites that had received their most recent sludge application
prior to 1987 (the study year) were monitored to establish the levels of LAS
in sludge amended soils. Thirty five (83%) of the samples contained LAS
levels below 1 mg/kg soil (mean = 0.7 mg/kg). The seven other sites
contained LAS levels between 1.1 and 2.5 mg/kg soil. Nine sites received
sludge applications in January to May 1987. Sampling was conducted in
May 1987 and resulted in LAS concentrations ranging from