Heavy metal contents of Azidirachta indica collected from Akungba- Akoko (Nigeria)

The levels of heavy metals in the tissues (roots, leaves and stems) of Azidirachta indica collected at di erent spots in Akungba-Akoko, Ondo State (Nigeria) were determined. Five heavy metals namely; cadmium (Cd), cobalt (Co) iron (Fe), lead (Pb) and zinc (Zn) were studied. The tissues were ashed, digested and the digestates were analyzed for the metals using flame atomic absorption spectrophotometer. The levels (ppm) of the heavy metals obtained in the roots, leaves and stems of the plant respectively ranged as follows: Cd (0.14 – 0.34, 0.09 – 0.20, 0.09 – 0.33); Co (4.01 – 5.48, 3.22 – 5.14, 3.84 – 5.40); Fe (82.27 – 137.98, 49.20 – 160.10, 58.33 – 116.62); Pb (0.50 – 0.57, 0.33 – 0.97, 0.28 – 0.48) and Zn (52.07 – 149.94, 52.01 – 113.73, 49.58 – 127.05). Fe has the highest levels while Cd has the lowest levels in all the tissues analyzed. The stems of the plant showed the least bioaccumulation of most metals studied and hence most suitable for medicinal purpose. Metals’ concentrations decrease in all the tissues with increasing distance from the highway. There is a growing concern about the physiological and behavioural e ects of environmental trace metals in human population, for medicinal purpose therefore, tissues of the plant and other medicinal plant should be sourced at distances very far away from the roadside.Key words- Heavy metals, Azidirachta indica, tolerable limits, anthropogenic sources, toxic e ects, biological tissues

Mercury levels and health parameters in the threatened Olrog’s Gull (Larus atlanticus) from Argentina

Mercury (Hg) exposure was investigated through feathers of Olrog's Gull and related to health parameters in adults (hematocrit, total plasma proteins, morphometric measures, sex) and chicks (hematocrit, total plasma proteins, immunoglobulins G and M) from a colony located in estuary of Bahia Blanca, Argentina. Mercury concentrations were 5.50 +/- 2.59 mu g g (-aEuro parts per thousand 1) (n = 44) in live adults, 1.85 +/- 0.45 mu g g (-aEuro parts per thousand 1) (n = 45) in live chicks and 1.81 +/- 0.41 mu g g (-aEuro parts per thousand 1) (n = 41) in dead chicks. Large differences were observed between live adults and live or dead chicks and small differences between live and dead chicks. In the adults, the sex of the birds was the variable that best explained Hg concentrations. Male birds had higher concentrations than females; this suggests that the clutch provides a sink for mercury during egg laying. Hg concentrations in both adults and live chicks were associated with higher hematocrits. This could be associated with upregulated erythropoiesis to compensate for increased rate of destruction of prematurely senescent, Hg-contaminated erythrocytes. Based on our results, on the levels of Hg pollution in the past in the study area, and on the dietary specialization of Olrog's Gull, we must be vigilant about potential negative effects of Hg pollution on this population and recommend continued monitoring on this threatened species