Fróðskaparrit - 01.07.2004, Síða 95

KYKSILVUR í FØROYUM - EIN GJØGNUMGONGD AV TØKUM DÁTUM
93
Cd Cr Cu Fe Ni Pb V Zn Hg
Hylocomium s. 1996 1,2 0,12 0,73 5,43 539 1,53 7,58 4,45 15,17
Average all locations, range 0,09-0,15 0,49-1,17 4,44-6,92 312-1064 1,19-1,91 5,37-10,3 3,21-6,84 12,0-21,6
Hylocomium s. 1996' 0,13 0,51 5,67 382 1,45 7,38 3,43 16,9
Hylocomium s. 2000 1 q 0,86 6,88 812 1,78 3,78 3,98 15,06 0,05
Average all locations, range 0,04-0,09 0,50-1,83 4,48-9,87 270-1755 1,02-2,97 2,18-5,94 1,81-8,03 10,7-20,3 0,02-0,07
Hylocomium s. 20001 0,05 0,54 7,21 878 1,95 3,67 2,50 13,7 0,05
Racomitrium lanuginosum 0,07 2,47 3,65 731 2,10 13,2 4,33 10,6 0,16
Cladonia mitis 0,08 2,42 16,5 251 2,22 2,35 0,84 20,4 0,14
1 The growth during the last 2-3 years were analysed.
2 Riihling eí al. 1996
Table 2 Heavy metals in moss and lichen, in mg/kg dw, sampled Norðurí á Fossum ,Vestmanna in 1997 and in
moss (Hylocomium splendens) sampled at Norðuri á Fossum plus 7 other locations in Eysturoy and in the
Streymoy in 1996 og 2000. (Dam, 1998; Larsen and Dam, 1999).
ses of so-called conservative elements, like
iron, so the degree of dusting may be in-
ferred from the magnitude of the conserva-
tive element in the moss. Not surprisingly,
the concentration of iron is high in the Hy-
locomium s. samples. Dividing the concen-
tration of mercury by the one of iron in the
various moss samples do not give a con-
stant value, which could otherwise be ex-
pected if the local geology was the source
of the mercury. Neither the lead/iron nor
the mercury/ironratio in moss is constant,
but interestingly, they correlate (squared
Pearson’s regression coeff. =0,83) with a
maximum value in the sampling site
renown for its high precipitation volume
(Saksunardalur/Hvalvík). These findings
indicate that the source of both mercury
and lead is not local geology and that depo-
sition of airborne metals frorn ntore remote
sources may be a significant contribution to
the measured moss metal concentration.
Comparing the results of the moss samples
to the 1995 European survey indicate that
the mercury concentration in Hylocomium
s. from the Faroe Islands are comparable to
what was found in Russia at the Kola penin-
sula and in the Leningrad and Pskov re-
gions as well as in Finland. Also, it may be
said that it was generally in the lower end of
what was found in Sweden, Norway, Den-
mark and the Baltic States (Riihling et al.,
1996; 1998).
In 2002 the uptake of mercury in vegeta-
tion was studied in uniclone grass (Lolium
multiflorum) specially grown for the pur-
pose in controlled circumstances and sta-
tioned at five stations on Eysturoy and
Streymoy during June to October (Dau-
gaard, 2003). The uptake of mercury in
grass was found to be positively correlated
(P<0,001) to the uptake of mercury in the
passive samplers, but in contrast to what
was expected, not to the total wet deposited
mercury. Also, a correlation to the elevation
of the station above sea level was found
(P<0,01). The study concluded that there
are no indications of an elevated exposure