Occurrence of DDA in DDT-contaminated sediments of the Southern California Bight

• Published in: Marine pollution bulletin 2012-07, Vol.64 (7), p.1300-1308
• Main Authors: Chen, Zhenshan, Chen, Li, Liu, Yu, Cui, Li, Tang, Chi-Li, Vega, Helen, Krieger, Robert I.
• Format: Article
• Language: English
• Subjects: California; DDA; DDD (pesticide); DDE; DDE (pesticide); DDMU; DDT; DDT (pesticide); DDT - analogs & derivatives; DDT - analysis; Environmental Monitoring; Geologic Sediments - chemistry; Insecticides - analysis; Marine; monitoring; Sediment; sediments; Southern California Bight; wastewater; Water Pollutants, Chemical - analysis; water pollution
• ISSN: 0025-326X; 1879-3363
• DOI: 10.1016/j.marpolbul.2012.05.010

► DDA, a water-soluble DDT metabolite, occurs in DDT-contaminated sediments. ► DDA levels occurred only at wastewater outfalls where DDT levels were present. ► DDA is missed by usual environmental monitoring procedures for DDT contamination. ► DDA may occur naturally in the recovery of DDT-contaminated sediments. DDT, DDE and some additional lipophilic derivatives are recognized contaminants in sediments of Southern California Bight (SCB). Only about 10% of total DDTs discharged into the SCB are accounted for using available monitoring data (sediment, water, and biota). DDA represented up to 0.03% DDTs (DDT/DDE/DDD) in SCB surface sediments (top 2cm) in amounts up to 76μgDDA/kg dry weight. Highest DDA levels were found where DDT and DDD levels were maximal at the primary wastewater outfall indicating a natural precursor-product relationship for DDT and DDA. Still culture of SCB sediment revealed limited DDA formation following DDT fortification. DDA residues have also been found in contaminated Long Island, NY sediments provided by USGS. The formation of DDA and its potential release from sediments may be significant in resolution of uncertainties concerning the natural recovery of sediments in DDT-contaminated environments.