RISK ASSESSMENT IN RELATION TO NEONATAL METAL EXPOSURE

Rapid changes in organ development and function occur during the neona tal period, During this period the central nervous system is in a rapi d growth rate and highly vulnerable to toxic effects of, e.g., lead an d methylmercury. Furthermore, the kinetics of many metals is age-speci fic, with a higher gastrointestinal absorption, less effective renal e xcretion as well as a less effective blood-brain barrier in newborns c ompared to adults, Due to their low body weight and high food consumpt ion per kg of body weight, the tissue levels of contaminants can reach higher levels in newborns than in adults, Generally, there is a low t ransfer of toxic metals through milk when maternal exposure levels are low, However, knowledge is limited about the lactational transport of metals and the potential effects of metals in the mammary gland on mi lk secretion and composition, There are some data from rodents on the lactational transfer and the uptake in the neonate of inorganic mercur y, methylmercury, lead and cadmium, Metal levels in human breast milk and blood samples from different exposure situations can-give informat ion on the correlation between blood and milk levels, If such a relati onship exists, milk levels can be used as an indicator of both materna l and neonatal exposure, Better understanding of the neonatal exposure , including kinetics in the lactating mother and in the newborn, and e ffects of toxic metals in different age groups is needed for the risk assessment, Interactions with nutritional factors and the great benefi cial value of breast-feeding should also be considered.