| Summary: | This dataset reports the HCB and ΣPCB (here defined as the sum of the following congeners: 31, 28, 45, 52, 44, 66, 101, 97, 87, 110, 151, 107, 149, 118, 146, 153, 105, 141, 179, 138, 182, 183, 128, 174, 177, 180, 170, 196, 194 and 206) concentrations in birds restricted to the Antarctic region during summer and winter (Adelie Penguin (n = 12), Snow Petrel (n = 4), Antarctic Petrel (n = 5) and Southern Fulmar (n = 18)) and birds wintering in sub-antarctic region (Cape Petrel breeding at Hop Island (n = 3) and Cape Petrel breeding at K. George Island (n = 6)) compared with birds living in temperate areas at the northern hemisphere during summer and in sub-tropical regions during winter (Common Tern (n=6)). Of these three categories of birds, the first one showed relatively low ΣPCB levels but higher HCB levels. The second one has ΣPCB concentrations significantly higher whereas HCB concentrations are also higher, but not significantly. The third category has relatively high levels of ΣPCB, but HCB concentrations are extremely low. Therefore the trend for ΣPCB is that species further away from potential sources (e.g. species confined to the Antarctic continent all year) have low concentrations while for HCB the pattern is different and can be explained by the cold-condenser or the global-distillation effect. HCB is relatively volatile, it has a high environmental half-life and it accumulates in species at higher trophic levels. The species in this study with relatively high HCB levels, are confined to the cold Antarctic region for at least a major part of the year whereas the Common Tern which inhabits temperate to sub-tropical areas throughout the year, where HCB apparently evaporates before it enters the food web, has extremely low concentrations.
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