The Last Two Centuries of Lead Pollution in the Southern Gulf of Mexico Recorded in the Annual Bands of the Scleractinian Coral Orbicella faveolata

Abstract

Lead (Pb) pollution history (1855-2001 A.D.) of the southern Gulf of Mexico (SGM) was reconstructed from the geochemical record contained in the annual bands of the hermatypic coral Orbicella faveolata from the Veracruz Reef System, Mexico. Pb concentrations ranged from 5.5μg/g in 1889-23.6μg/g in 1992, with an average of 10.0±4.1μg/g. These high concentrations are evidence of a highly polluted environment. High statistical correlations were observed between the annual Pb coral time-series and both, the production of alkyl-lead gasoline in Mexico during the second half of the twentieth century (r=0.86, p<0.001), and the industrial production of lead in North America for the 1900-1940years period (r=0.73, p<0.001). Hence, this research provides evidence that these two processes generated Pb-rich aerosols that were atmospherically transported, increasing the environmental levels of Pb in the SGM.