Mercury was not regarded as a pollutant of primary importance until ma
ny deaths due to mercury poisoning occurred in the 1950s. More recentl
y, adverse health effects have been documented at relatively low expos
ure levels, and monitoring data must now be interpreted in this light.
The Mediterranean basin has been studied in great detail over the pas
t 20 years because of the anomalous natural presence of mercury. Marin
e animals of this basin have higher mercury body burdens than the same
(or similar) species in the Atlantic. The mercury found in marine org
anisms is mainly in the form of methyl mercury. Long-term and frequent
intake of seafood with high mercury levels by populations living in c
oastal fishing villages is associated with a toxic risk, especially in
pregnant women. High blood and hair concentrations of mercury have re
peatedly been found in fishermen of Tyrrhenian coastal villages. In so
me cases these concentrations have been associated with an increase in
DNA damage in blood cells. High mercury levels in hair and blood of p
eople from a fishing village of Madeira have also been found. This inf
ormation deserves renewed scrutiny with regard to preventive efforts n
eeded. (C) 1998 Academic Press.