Lifestyles, diets, and Native American exposure factors related to possible lead exposures and toxicity

Lead exposure is still a national concern, and it is possible that Native Americans who live on reservations and pursue traditional lifestyles may be at higher risk through both their unique exposure profiles and their potentially greater sensitivity. A major component of the exposure assessment is the diet. For tribal members, traditional lifestyles that include native foods, medicines, and traditional practices have evolved and proven to be the most healthful over many thousands of years of coexistence with the environment. However, a completely traditional diet may not be fully available for a variety of reasons; so, one must also consider the adverse health consequences caused by the loss of healthy native foods and medicines, the contamination of remaining native foods, the inability to practice one's religion, and the possibly lower quality of the substitute diet. Health evaluations of lead exposure on reservations should therefore consider at least two types of diets in addition to the typical suburban diet: (a) traditional diets composed of native foods and medicines that would result in increased exposure if the plants and animals are contaminated and (b) disadvantaged or commodity food diets that result in widespread vitamin and mineral deficits of the sort known to increase absorption of and response to lead. Additional exposure to lead might come from reservation housing which is often older, although the prevalence of lead-based paint on reservations is unknown. The degree of physiological response could also be affected by widespread exposures to other neurotoxins (such as mercury and PCBs in fish), underlying disease patterns, and genetics. Although each of these factors is plausible, their prevalence singly or in combination is unknown. Any correlation between these risk factors and blood lead levels on reservations is also unknown. This paper begins to address these gaps by discussing the range of traditional and current diets that may exist among tribes and methods for developing a whole-lifestyle exposure scenario that is appropriate for an individual tribe. Some of the factors discussed in this paper may not apply to the large population of Native Americans who live in urban situations.