Effectiveness of leaded petrol phase-out in Tianjin, China based on the aerosol lead concentration and isotope abundance ratio

摘要

The phase-out of leaded petrol has been a measure widely used to reduce atmospheric lead pollution. Since the 1980s, China began to promote unleaded petrol. In order to assess the effectiveness of the measure an isotope fingerprint technique was applied for aerosol samples in the city of Tianjin. After dilute acid leaching, the lead concentration and isotope abundance ratios were determined for 123 samples collected in Tianjin during eight years (1994-2001). The Pb-206/Pb-207 ratio was lower in summer, when coal combustion emission was low and vehicle exhaust became more important, indicating that the Pb-206/Pb-207 ratio of leaded petrol in Tianjin is lower than that of aerosol samples. The Pb-206/Pb-207 ratio gradually increased from 1994 to 2001, a trend that suggests that the contribution from vehicle exhaust was diminishing. Overall, the measurements matched well with national statistical data of leaded and unleaded petrol production. After the nationwide switch to unleaded gasoline, comprehensive control measures are urgently needed to reduce an-lead pollution in China, as aerosol lead reduced slightly but remains at a relatively high level. (c) 2005 Elsevier B.V. All rights reserved.