Environmental Engineering Reference
In-Depth Information
HCB and other POP contents (Pastor et al. 1995). The question of the laying influence on
POPs has been recently reviewed by Van den Steen et al. (2009b), but although a decline in
POP concentrations is usually observed in relation to the laying order, within the clutch
the variation was larger than that among clutches (Van den Steen et al. 2009a). Finally,
another potential drawback of the use of eggs is that, for many protected species, only
unhatched, addled, sterile, and/or broken eggs are collected and analyzed (Hernández
et al. 2008; Clark et al. 2009; Vorkamp et al. 2009; Best et al. 2010); so the data are potentially
biased due to the worst situation.
Tables 14.2
and 14.3 show the concentrations of HCB in nonraptorial and raptorial birds'
eggs from selected papers published in the last 10 years. A comparison of the levels among
species is difficult to carry out, since most studies have been done on whole eggs (yolk
and albumen) while others have used only yolk; units are reported sometimes on wet and
sometimes on dry or even lipid weight basis; and many authors give arithmetic means,
while some others give geometric ones, medians, or simply a range. However, for practical
purposes and as a sufficient approximation for basic evaluation, some recalculations can be
made taking into account the values of lipid content and moisture in eggs reported in the
recent literature. Lipid content usually ranges from a minimum of 3.8% to a maximum of
18% (Mora et al. 2008; Henny et al. 2009), but typically values around 7%-12% are reported
for all species (Elliot et al. 2001; Vorkamp et al. 2004; Jaspers et al. 2005; Braune 2007; Bustnes
et al. 2007; Henny et al. 2008a; Helgason et al. 2008; Lavoie et al. 2010). Moisture ranges
from a minimum of 63.9% to a maximum of 81.7% (Henny et al. 2008a; Mora et al. 2008), but
most values are around 70%-78% (Elliot et al. 2001; Mañosa et al. 2003; Albanis et al. 2003;
Braune 2007; Lavoie et al. 2010).
Accordingly, assuming round percentages of 10% for lipid and 25% for dry matter in eggs,
no great differences for HCB can be observed, as concentrations ranged from nondetectable
(below the limit of detection or quantitation) to the highest value of ≈66.5 ng/g WW in
Atlantic puffins (
Fratercula arctica
) from Northern Norway (Helgason et al. 2008). Values
≥30 ng/g WW were also found in the species of the Arctic or sub-Arctic regions, such as
black guillemots (
Cepphus grylle
) from Greenland (Vorkamp et al. 2004), northern fulmars
(
Fulmarus glacialis
) and thick-billed murres (
Uria lomvia
) from Canada (Braune et al. 2001;
Braune 2007), and herring gulls (
Larus argentatus
), black-legged kittiwakes (
Rissa tridactyla
),
and common guillemots (
Uria aalge
) from Norway (Helgason et al. 2008).
In a study of the subcutaneous fat of 61 individuals belonging to eight albatross spe-
cies (
Diomedea
spp. and
Phoebetria palpebrata
) from the North Pacific and Southern Ocean,
Guruge et al. (2001) found no marked differences in the content of HCB among the species
or between the hemispheres, in contrast to other POPs for which differences of at least one
order of magnitude higher was detected in North Pacific individuals. This was attributed
by the authors to the dispersive nature of HCB though long-range atmospheric transport,
which contributes to uniform levels on a planetary scale, including the Antarctic region
(Goerke et al. 2004).
14.3.1.2 Mammals
HCB, like other POPs, is highly lipophilic and thus accumulates in the blubber, a dense
vascularized fatty tissue beneath the skin, of marine mammals. Blubber has a lipid content
of 60%-90% and may constitute up to 50% of the body mass of some species at certain life
stages (Colborn and Smolen 1996; Dietz et al. 2000). A selection of the concentration values
of HCB in the blubber of different marine mammals (cetaceans and pinnipeds), published
in the last 10 years, is presented in Table 14.4. Although not fully aquatic and lacking “true”
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