Because hypertension is thought to account for the greatest degree of African American heart disease, understanding its cause is critical. Discrepancies in reporting prevalence in blacks with similar genetic backgrounds but different geographic locations hint at a significant role of environmental and cultural influences. For example, the prevalence of hypertension is reported as 8-10 % in rural Africa compared with 33% in the United States (24). Because of this disparity, understanding the role of environmental exposures may be extremely important.