Mercury levels in sediments and mangrove oysters, Crassostrea rizophorae, from the north coast of Villa Clara, Cuba.

Total mercury levels were quantified in sediments and oyster tissues (Crassostrea rizophorae) from the Sagua la Grande River estuary and offshore mangrove keys 19 km downstream of a chlor-alkali plant (CAP) in Villa Clara, Cuba. Relatively elevated total mercury levels were found in sediments from the estuary itself, ranging from 0.507 to 1.81 µg g(-1) dry weight. However, levels were lower in sediments from the keys farther from the estuary. Oyster mercury levels were always acceptable for human consumption, although levels significantly correlated in sediments and oysters across sampling sites (p < 0.05), which suggests that mercury from the CAP is impacting coastal water quality conditions.

Assessment of total mercury levels in Clarias gariepinus from the Sagua la Grande River, Cuba.

Total mercury levels (Thg) were quantified in Clarias gariepinus captured from the Sagua la Grande River (Cuba) in the vicinity of an active chlor-alkali plant, and relationships among place of capture; fish size, weight, and sex; and THg levels were assessed. THg levels ranged from 67 to 375 ng/g ww in collected fish, never exceeding the Cuban recommended maximum limit for fish consumption of 500 ng/g ww. No significant correlation was observed between mercury levels and fish allometric characteristics (p < 0.05); however, levels were significantly higher in fish captured below the chlor-alkali facility, suggesting a connection between mercury bioaccumulation and plant discharges.

Water hyacinths (Eichhornia crassipes) as indicators of heavy metal impact of a large landfill on the Almendares River near Havana, Cuba.

The Almendares River is central to recreational and other activities in Havana, Cuba. However, monitoring indicated significant heavy metal contamination in river sediments, especially below Calle 100, the largest landfill in Havana. This work extended previous sediment studies by determining complementary Cu, Pb, Ni, Cr, Cd, and Zn levels in indigenous water hyacinths (Eichhornia crassipes; EC) above and below the landfill. Pb, Cu, and Zn were significantly elevated in EC roots below the landfill and also correlated with sediment data (p < 0.05), implying elevated levels likely result from landfill activity and might be useful biomonitors as river remediation proceeds.

Characterization of ophiolites from northern Havana-Matanzas petroleum fields using instrumental neutron activation analysis.

Concentrations of 16 elements from 14 serpentinitic samples from Basilio and Cantel petroleum fields were obtained by instrumental neutron activation analysis (INAA): Cr, Co, Ni, La, Nd, Sm, Eu, Gd, Tb, Ce Yb, Lu, Rb, Cs, Hf and Th. Relative INAA was performed using certified reference materials and laboratory standards. Average elemental concentrations showed that the ophiolites have a basic character, suggesting the use of a well-logging method designed for volcano-sedimentary petroleum fields.