Spatial distribution of chlordanes and PCB congeners in soil in Cedar Rapids, Iowa, USA

Residential soils from Cedar Rapids, Iowa, USA were collected and analyzed for chlordanes and polychlorinated biphenyls (PCBs). This study is one of the very few urban soil investigations in the USA. The chlordanes concentrations ranged from 0 to 7500 ng g−1 dry weight (d.w.), with a mean and standard deviation of 130 ± 920 ng g−1 d.w., which is about 1000 times larger than background levels. ΣPCB concentrations ranged from 3 to 1200 ng g−1 d.w., with a mean and standard deviation of 56 ± 160 ng g−1 d.w. and are about 10 times higher than world-wide background levels. Both groups exhibit considerable variability in chemical patterns and site-to-site concentrations. Although no measurements of dioxins were carried out, the potential toxicity due to the 12 dioxin-like PCBs found in the soil is in the same order of magnitude of the provisional threshold recommended by USEPA to perform soil remediation.

Graphical AbstractSpatial location and measured concentrations of ΣPCB (left, 64 sites) and chlordanes (right, 66 sites) (ng g−1 d.w.) in soil from Cedar Rapids, Iowa. Samples were collected in August 2008. Estimated flood area was obtained from the Linn County Auditor's Office. For more details see Tables S1 and S2.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Chlordanes and PCBs congeners were measured in surficial soil from Cedar Rapids, Iowa. ► Measured values for both chemical groups are similar to other urban/industrial site around the world. ► This is one of the few urban soil studies in the USA. ► TEQs values are in the same order of magnitude of the provisional threshold recommended by USEPA to perform soil remediation.