Evidence from worldwide environmental contamination by lead, as a result of anthropogenic emissions, has been documented. According to lead measurements made in Greenland’s ice and snow in the mid 1960s, over 99% of the lead in the global troposphere of the Northern hemisphere was anthropogenic (Murozomi et al., 1969; Robinson and Robbins, 1971). However, Boutron et al.(1991) found that, as a result of recent limited use of leaded gasoline by the US, Canada, and the European countries, lead concentrations in recently deposited Greenland snow decreased by a factor of 7.5 since the 1970s. Shen and Boyle (1987) found the same decreasing trend in North Atlantic sea water. During the seventies the northeastern coast of the Yucatan Peninsula experienced explosive human development resulting from growth of the tourist center, Cancun. Since its establishment, dredging and land clearing activities have been continually performed, and Cancun Island, the hotel center, has been expanded with large amounts of sand taken from nearby localities, and from the sea, to foster development (Marti, 1985; Dachary and Burne, 1986). The coastal population increased from one family to more than 357,000 inhabitants, with nearly 2.3 million visitors annually, in three decades (INEGI, 1997).

To assess lead contamination resulting from this explosive human development in the northeastern part of the Yucatan Peninsula, a lead chronology based on the analysis of lattice-bound lead concentrations in an annually banded scleractinian coral from Cancun, was determined. A similar chronology was obtained from coral collected in a pristine area located on the southeast coast of the Peninsula.