Daily intake of manganese by the adult population of Mumbai

The daily intake of manganese (Mn) estimated through air, water and duplica te dietary analysis is found to range from 0.67 to 4.99 mg with a mean valu e of 2.21 mg. Ingestion through food contributed to the predominant fractio n of the intake. The turnover rate of Mn through blood is approximately 2 h , based on the mean concentration of Mn in blood of 1.54 mu g l(-1). The av erage concentrations of Mn in water and air were approximately 1.42 mu g l( -1) and 37 ng m(-3), respectively. The daily intake of Mn by the adult popu lation of Mumbai is closer to the lower bound of the recommended limit of 2 -5 mg. Electro Thermal Atomic Absorption Spectrophotometry (ET-AAS), has be en used for the determination of Mn in a variety of environmental and human biological fluids. The detection limit of Mn for a volume injection of 20 mu l is 2 pg absolute. The precision of the method is established by analyz ing a synthetic mixture containing various elements in different quantities (0.5-10 ppm) and is found to be within +/-8%. The reliability of estimatio n is further assessed through the analysis of Standard Reference Materials (SRMs) of soil, hay, milk powder and fish tissue obtained from IAEA. (C) 20 00 Elsevier Science B.V. All rights reserved.