Elemental status of grazing animals located adjacent to the London Orbital (M25) motorway.

The elemental (Br, Cd, Cr, Cu, Mn, Ni, Pb, Se, V, and Zn) content of blood and wool or hair from animals (sheep, horses and alpacas) exposed to motor vehicle emissions alongside the London Orbital (M25) motorway is reported. Elemental values were determined by inductively coupled plasma mass spectrometry (ICP-MS) quality control assessment using flameless atomic absorption spectroscopy (for Pb, correlation coefficients of whole blood r = +0.87, and hair r = +0.82), and replicate (n = 10) analysis of the international reference material IAEA A13 Animal Blood. For Pb very good agreement was obtained between ICP-MS values 0.16 +/- 0.002 microgram/g and non-certified values 0.18 microgram/g. Only Pb and Cd showed significantly elevated blood levels in sheep grazing alongside the M25 motorway when compared with control (background) animals. The range of Pb blood values was 0.15-0.51 microgram/ml (M25) and 0.04-0.18 microgram/ml (control), respectively. The elemental content of the outside (tip) end of wool samples for the two study groups were significantly elevated in Br, Cd, Cr, Cu, Ni, Pb, V, and Zn for M25-exposed animals compared with controls. Elevated Pb and Cd were also found in horses' and alpacas' blood or hair in animals exposed to transportational activities. The relationship between whole blood and outer wool or hair Pb showed a very highly significant correlation for sheep (r = +0.89), horses (r = +0.69), and alpacas (r = +0.74) grazing alongside the M25 motorway.