INORGANIC BORATES - CHEMISTRY, HUMAN EXPOSURE, AND HEALTH AND REGULATORY GUIDELINES

Risk assessment of essential or nutritionally important trace elements occurring naturally in foods and the environment poses many challenge s to health advisory bodies and regulatory agencies when setting accep table daily intake levels of these elements, especially in media such as drinking water. The use of traditional 100-fold safety factors appl ied to animal-derived, no-effect levels for some essential elements ca n unwittingly lead to calculated acceptable daily intakes below levels that are recognized as nutritional requirements. Boron (B) is widely distributed in the environment combined with oxygen to form inorganic berates. It has been known for 75 years that B is an essential micronu trient for plant growth, and as such it occurs naturally in all fruits , vegetables, grains, nuts,legumes, wine, and to a lesser extent in mo st other foods and beverages. Drinking waters and some mineral waters from areas naturally high in B also may contribute to human daily inta ke. Human and animal studies provide strong support that B is a nutrit ionally beneficial, if not essential, element for humans, and it is po ssible that B deficiency may pose potential health risks. Recent estim ates show that the mean dietary intake of B in the United States is 1 mg/day, although B intakes can vary considerably across national diets , especially those that contain higher amounts of fruits and vegetable s. National and international health advisory and regulatory bodies sh ould consider both the ubiquity and nutritional importance of B as par t of a healthy diet when setting standards and guidelines based on ani mal toxicology-derived, no-effect-levels. (C) 1997 Wiley-Liss, Inc.