Transport of elements from soil to human diet: an alternative approach to pathway analysis.

Transport from soil to human dietary intake is conventionally treated by analyzing the various pathways through uptake by plant roots and transfer from animal feed into milk and meat. An alternative approach is proposed requiring only the average daily human ingestion of each element and its abundance in soil, both readily available for most elements. The two methods are compared quantitatively and give results consistent within a mean factor of four, which is roughly the standard deviation in estimates from the pathway analysis. Neither method gives consistently larger or smaller transfer rates. Each method has important advantages in some applications.