Concentration of three heavy metals (mercury (Hg), lead, (Pb), and cadmium, (Cd)) and one metalloid (arsenic [As]), were determined by atomic absorption spectrophotometry in five tissues (muscles, liver, kidneys, gills, and gonads) of five fish species (carp-Cyprinus carpio, tench-Tinca tinca, sval-Leuciscus svallizi, gray mullet-Mugil cephalus, and eel-Anguilla anguilla) taken out from the end fIow (last 20 km) of the river Neretva, south Croatia, in the wider region of town Metković, during the summer of the year 2003. Only Cd concentration in all fish types was higher than the maximal allowed concentration (MAC) in Croatia, but its concentration in muscles reaches this value only in four samples. However, in carp, tench, and mullet, Cd concentrations higher than MAC in some other countries were found. Hg concentration is much lower than MAC in the most countries. Pb is found in higher quantities only in carp, some values reaching MAC in Germany, and many values being higher than MAC in Denmark (with exception of gonads). As concentrations are much lower than MAC in all countries, but it seems that mullet tends to accumulate this metalloid, especially in the muscles. Therefore, in several samples, muscle As concentration in mullet reached half of the MAC value in the most countries. Of the analyzed fish types, eel, containing the smallest quantities of heavy metals, is recommended for human diet, while carp, consumed most frequently by local inhabitants and numerous tourists, shares with mullet the last place on the recommendation list. Also, it is suggested that meals prepared with analyzed fish sorts should not contain some inner organs (kidneys and liver), as well as gills (alternatively, the whole head). Our final conclusion is that fish types eating predominantly meat contain less heavy metal in their tissues, and therefore are more suitable for human diet.
