Monitoring of the exposure to platinum-group elements for two Italian population groups through urine analysis

Abstract

It is well recognized that automobile catalytic converters are the main source of Pd, Pt and Rh (also called platinum-group elements (PGEs)) in an urban atmosphere. Over recent years, urinary biomonitoring of PGEs has gained considerable importance in assessing the individual human exposure to these elements. This paper reports the concentration ranges of PGEs in the urine of 257 Italian subjects, aged between 23 and 88 years. Subjects were selected on the basis of standardized criteria in two different Italian cities, so as to represent a small urban area surrounded by an essentially rural environment and characterized by low automobile-traffic density (Foligno) and a large urban area with almost constant high-traffic conditions (Rome). The determination of PGEs was performed by sector field inductively coupled plasma-mass spectrometry (SF-ICP-MS) after 1:4 (v/v) dilution of the samples. The 5th and 95th percentiles for PGEs in urine of subjects living in Foligno were the following (in ng l −1): Pd 1.99–17.2, Pt 0.24–3.08 and Rh 0.53–14.8. The 5th and 95th percentiles in the urine of subjects from the area of Rome were (in ng l −1): Pd 0.71–17.0, Pt 0.49–8.13 and Rh 4.10–38.6. Platinum and Rh median concentration values showed large and significant differences ( P<0.0001) between the two urban settings considered (0.52 and 3.50 ng l −1 for Pt and Rh in Foligno, respectively, and 1.70 and 12.85 ng l −1 for Pt and Rh in Rome, respectively). On the other hand, no striking differences were found in the Pd concentration (median value of 6.02 ng l −1 in Foligno versus 7.79 ng l −1 in Rome). The sex variable correlates only with Pd concentration ( P=0.05), pointing out that in males concentrations are higher than in females.