The concentrations of lead and total hydrocarbons in the tissues of the periwinkles
Tympanotonus fuscatus
and
Pachymelania aurita
from the upper Bonny River were determined. The highest mean values of lead and total hydrocarbons were 9.45mg/g and 1242.19mg/g respectively. The results showed higher concentrations of lead and hydrocarbons in the creeks than in the open river. The concentrations of lead and total hydrocarbons measured at the control site were lower than the concentrations measured at the study sites. The concentrations of Pb and THC were generally higher in the shells than in the tissues of periwinkles in the study areas. T - tests showed no significant difference in concentration between tissues and shells of the organism with high correlations (P < 0.05, r = 0.9947 for Pb and P > 0.05, r = 0.9611 for THC). The relationships between the concentrations of Pb and THC in the tissues and shells were observed to follow linear and polynomial regression equations. The levels of Pb and THC were higher along the main river than the creeks as a result of dilution and flushing effects of current and volume of water. The levels of lead and total hydrocarbons in the periwinkles were attributed to emissions from automobiles using leaded gasoline for both land and sea transportation in addition to effluents, oil spills and surface coatings from moving and abandoned engine boats as well as industrial and domestic wastes containing metal parts and hydrocarbons. @JASEM
