Trace Element Concentrations in Raillietina micracantha in Comparison to Its Definitive Host, the Feral Pigeon Columba livia in Santa Cruz de Tenerife (Canary Archipelago, Spain)

Abstract

The use of systems involving bird parasites as bioindicators of environmental pollution has been scarcely studied in comparison to other models involving fish and rodent parasites, which have been demonstrated as particularly adequate due to their bioaccumulation capacities. The present study evaluated the accumulation of nine trace elements in the cestode Raillietina micracantha and in its host Columba livia collected from the densely populated city of Santa Cruz de Tenerife (Canary Islands, Spain). Samples (kidney, liver, pectoral muscle, feathers, and R. micracantha) of 27 infected C. livia were selected for trace element analysis by inductively coupled plasma-mass spectrometry. Element levels in pigeon tissues revealed some degree of pollution in Santa Cruz de Tenerife, particularly by Pb and Zn. Pb and Mn mean concentrations were higher in R. micracantha than in the pigeon's soft tissues, with subsequent high bioaccumulation factors for Pb (kidney = 15.38, liver = 10.38, muscle = 79.83) and Mn (kidney = 6.81, liver = 7.52, muscle = 19.89, feathers = 6.11), among others. The negative relations detected for As concentrations between liver and R. micracantha emphasize a possible role of the cestode in As detoxification in host tissues. Considering the obtained bioaccumulation factors, the system R. micracantha/C. livia is proposed as another promising bioindicator system to evaluate environmental toxic element exposure, particularly Pb and Mn, in areas where pollution levels are still relatively low and where both common species are present.

Levels of Heavy Metals in Different Tissues of Pigeon (Columba livia) of Bangladesh for Safety Assessment for Human Consumption

“…This research showed that the intestine, kidney, gizzard, and liver have almost higher metal concentrations than the muscle. Such pattern has been observed in a number of other studies, covering a wide spectrum of pigeon (Torres et al 2010;Nam et al 2006;Schilderman et al 1997). In Bangladesh, the recent average per capita consumption of fish/meat was 21 g/person/day for males and females of all ages (Begum et al 2005).…”

“…The same distribution pattern of Cd was recorded (highest levels in the liver, lowest in the muscle) in other pigeons in spain (Torres et al 2010). The maximum admissible value for pigeon is 0.05 µg/g wet weight (EU Commission 2001).…”

“…From our experimental study, it was vividly observed that Cd in the muscle of pigeon from the different locations of Bangladesh was below the abovediscussed standard values, but long period of accumulation of Cd in pigeon might still be a health hazard. The Cr level in the muscle of C. livia, was 3.37 µg/g, which is higher than the results observed by Torres et al (2010). According to these results, it could be suggested that there is dense Cr pollution that might have resulted from the effluents from the tannery industries which has already reported (Mohanta et al 2010;Ahmed et al 2011) to have adversely affected the pigeon consumption by the local people.…”

“…A significantly higher level of Cu in the muscle than in the liver and intestine has been also observed (Torres et al 2010). According to Pyle et al (2005), Cu concentrations in liver are usually regulated by a homeostatic control below 50 µg/g dw and can exceed this threshold only if the control mechanisms are overloaded.…”

“…The elemental concentrations in the tissues of pigeon did not vary significantly among the five locations. In order to evaluate the elemental concentrations in the pigeon tissues, we compared the measured values with those in the tissues obtained at other places (Torres et al 2010;Schilderman et al 1997;Hutton et al 1980;Nam et al 2006; Table 3). …”