Polycyclic aromatic hydrocarbons (PAH) and polychlorinated biphenyls (PCB) in urban soils of Greater London, UK

Surface soils from a 19 km(2) area in east London, UK were analysed for polycyclic aromatic hydrocarbons (PAH) and polychlorinated biphenyls (PCB) (n = 76). Sigma(16) PAH ranged from 4 to 67 mg/ kg (mean, 18 mg/kg) and Sigma(50) PAH ranged from 6 to 88 mg/kg (mean, 25 mg/ kg). Sigma(7) PCB ranged from 1 to 750 mu g/kg (mean, 22 mu g/kg) and Sigma(tri-hepta) PCB ranged 9 to 2600 mu g/kg (mean, 120 mu g/kg). Compared to other international cities concentrations were similar for PAH but higher for PCB. Normal background concentrations (NBC) were calculated and compared to risk-based human health generic assessment criteria (GAC). Benzo[a] pyrene NBC for urban (6.9 mg/kg), semi-urban (4.4 mg/kg) and urban + semi urban (6 mg/kg) domains exceed residential (1 mg/kg) and allotment (2.2 mg/ kg) LQM/CIEH GAC (at 6% SOM) and the Indeno[1,2,3-cd] pyrene NBC for urban (6.8 mg/kg) and urban + semi-urban (5.2 mg/kg) domains exceed the residential (4.2 mg/kg) LQM/CIEH GAC (at 6% SOM). Capsule Abstract: Normal background concentrations of polycyclic aromatic hydrocarbons and polychlorinated biphenyls are elevated in east London soils and in some cases exceed regulatory assessment criteria. (C) 2014 The Authors. Published by Elsevier Ltd.