Environmental Engineering Reference
In-Depth Information
Fig. 4.4
IC
25
, IC
50
and IC
75
values and their 95 % confidence intervals (CI) (mg/L) for
Vicia
sativa
L. after 72 h application; the mean of three determinations with standard deviation
than that of
S. alba
. No significant differences were confirmed between the Cr(III)
and Cr(VI) adverse effects on
V. sativa
shoot growth. On the basis of these values,
and their statistical evaluation, metals can be arranged in the following rank orders
of inhibition: for roots: Ni(II) > Cr(VI) > Cr(III); for shoots: Ni(II) > Cr(VI) ≥ Cr (III).
For mutagenicity assay, root tips of
V. sativa
were used and chromosome aber-
rations were determined at least in 500-anatelophases. All tested metals exerted
a significant increase of chromosomal aberration rate in
V. sativa
due to ap-
plied concentrations (Table
4.1
). All tested metals Cr(VI) invoked maximum of
aberrations in anatelophase cells. The rank order of aberrations occurred was:
Cr(VI) > Ni(II) > Cr(III). Genetic variation in susceptibility to environmental agents
and metals can be considered as differences in metabolism of these agents in vari-
ous organisms (Omenn
1991
). In addition, DNA target size and DNA content are
also important in determining genotoxic hazards of metals. According to Kovalchuk
et al. (
1998
) and Chauhan et al. (
1998
) genotoxicity can be obtained as a result of
multipolar anaphase and c-mitosis or damage of protein synthesis in the presence
of DNA toxicant. Simultaneous toxicity and clastogenity of wastes with Cr and Ni
contents was also confirmed for
V. sati
va by Miadoková et al. (
1999
) and for
V.
faba
and
Allium cepa
by Chandra et al. (
2004
,
2005
). Chromosomal fragments and
bridges created in the presence of Cr(VI) indicated that CrO
3
affected DNA struc-
ture and conformation (Quian
2004
).
For determination the genotoxic effects of Cr and Ni, analysis of micronu-
clei frequency in the pollen tetrads of
Tradescantia
plants was done. As it is ev-
ident from Table
4.2
, none of tested metals significantly stimulated micronuclei
frequency in comparison with the control and genotoxic effect decreased in or-
der: Cr(VI) ≥ Ni(II) > Cr(III).
Tradescantia
micronucleus test (Trad-MCN) in
