Fig. 2: Time series of Pb/Ca, 206Pb/207Pb, and 208Pb/206Pb in the Dongsha coral.
From: Coral records indicate six-decade rise and fall of atmospheric lead emission in China
The time series is divided into four distinct periods. The phase-out of Pb gasoline in China in 2000 is delineated by a grey dashed line. The error bars (1σ) of the Pb/Ca indicate the standard deviation of the mean for triplicate measurements, and Pb isotope ratios were determined through single measurements, with error bars representing the 2σ uncertainty. The error bars (2σ) shown in the panels of Pb isotope ratios represent the analytical precision of the NIST SRM981 values at a concentration comparable to the samples, with precisions of 0.00025 for 206Pb/207Pb and 0.00074 for 208Pb/206Pb.
