First study on anthropogenic Pt, Pd, and Rh levels in soils from major avenues of São Paulo City, Brazil

• Published in: Environmental monitoring and assessment Vol. 184; no. 12; pp. 7373 - 7382
• Main Authors: Ribeiro, A. P., Figueiredo, A. M. G., Sarkis, J. E. S., Hortellani, M. A., Markert, B.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-12-2012
• Subjects: Atmospheric Protection/Air Quality Control/Air Pollution; Brazil; Cities; Earth and Environmental Science; Ecology; Ecotoxicology; Environment; Environmental Management; Environmental Monitoring; Humans; Monitoring/Environmental Analysis; Motor Vehicles; Palladium - analysis; Platinum - analysis; Rhodium - analysis; Soil - chemistry; Soil Pollutants - analysis; Brazil; Brazil, Sao Paulo; São Paulo; Urban soil; Catalytic exhausts; Platinum group elements
• ISSN: 0167-6369; 1573-2959
• DOI: 10.1007/s10661-011-2506-8

Over the last years, investigations on the increase of platinum (Pt), palladium (Pd), and rhodium (Rh) levels in urban environments of big cities all over the world - especially to catalytic converters emissions - have been grown up enormously. São Paulo City is the 6th largest megacity in the world having about 20 million inhabitants and an ever increasing seven million motor vehicle fleet. In spite of this, there has never been an investigation regarding Pt, Pd, and Rh levels in the city. In the present study, Pt, Pd, and Rh concentrations were determined in soils adjacent to seven main high-density traffic avenues in the metropolitan region of São Paulo City. Inductively coupled plasma mass spectrometry was employed - after ultrasound-assisted
aqua regia
leaching - as analytical technigue. The results showed concentration levels up to 378 ng g
−1
for Pd, 208 ng g
−1
for Pt, and 0.2 to 45 ng g
−1
for Rh. These levels are much higher than those considered for the geochemical background of soils, indicating a catalytic converter source. Due to the different Pt/Pd/Rh ratio in Brazilian automobile catalytic converters, lower levels of Pt/Pd ratios compared with other similar studies were observed. The obtained results are the first data for monitoring Pt, Pd, and Rh pollution in São Paulo City soils.