Metals of the bottom muds in Belize City Harbor, Belize

Seven bottom samples extending from the ocean up through Belize Harbor and City were acid leached (EPA method 200.7) and analyzed using inductively coupled plasma spectrometry to measure the bioavailability of Cd, Cr, Cu, Pb and Zn. Soil and environmental chemists would compare data to world averages of unpolluted soils, these samples were higher than this average by a factor of 10 for Cd, 4 for Cu, 2.7 for Zn and 2.6 for Pb. Geochemists argue that it's hard to find unpolluted soil so their comparison is with world average of ancient (pre-man) shales and the Belize samples were higher than this shale average by a factor of 30 for Cd, 3.7 for Pb, 2.2 for Cu and 1.7 for Zn. Ecologists would argue that the metal effect on the biota is the correct way to analyze the data by using the biological effects toxicity method, and this way the samples were above the lower limit by a factor of 5.1 for Cd, 2.9 for Cu and 1.6 for Pb. By all three lines of reasoning, it can be concluded that Cd, Cu, Pb and Zn, in that order, pose environmental problems. Since this site is located in the middle of Belize Barrier Reef, a highly sensitive environmental area that is also economically important to Belize, it poses a critical problem that needs to be addressed further.