Association of antimony with traffic — occurrence in airborne dust, deposition and accumulation in standardized grass cultures

Airborne antimony was sampled in two fractions of particles by a dichotomous sampler (dichot. fine mode and dichot. coarse mode) at two locations in Munich with different traffic impact. Parallel to the sampling of airborne dust, antimony was determined by two standard methods according to VDI-guidelines. Sampling of ‘total deposition’ (wet and dry) was achieved according to the Bergerhoff method (VDI, 1972) [VDI. Guideline 2119, part 2, measurement of dustfall. Bergerhoff instrument (standard method). In: VDI. Handbuch der Reinhaltung der Luft, 1972] and active biomonitoring was performed by exposure of standardized grass cultures (VDI, 1991) (VDI. Guideline 3792, part 3, measurement of the response dose. Measurement of the response dose of ambient lead in plants with standardized grass cultures. In: VDI. Handbuch der Reinhaltung der Luft, 1991). The highest airborne antimony concentrations of 14.0 ng/m (median) were found in close vicinity to traffic, with a maximum enrichment of 11.3 ng/m on particles of the dc-mode [aerodynamic diameters (dae) 2.5 μm ≤dae≤10 μm]. Antimony enrichment near traffic was confirmed by monitoring with standardized grass cultures and total depositions. Results of grass and deposition analysis after nitric acid digestion and subsequent digestion with hydrofluoric acid were compared. They illustrate that the second digestion step produced an increasing effect only on antimony concentrations in grass. Further, antimony on df-mode particles (dae ≤ 2.5 μm) correlated significantly positively with antimony deposition near traffic (significance level, α = 0.05, r = 0.786). These results suggest that the metal compounds of traffic-derived antimony in the two matrices might be different.