2 research outputs found
Plants as biomonitors for volcanic emissions
Biomonitoring techniques have been widely used in environmental studies to monitor anthropogenic
pollutant. Recently such techniques have been applied also to ascertain the impact of contaminants naturally
released by volcanic activity.
In the present study a biomonitoring surveys has been performed in many different active volcanic systems:
Mt. Etna and Vulcano (Italy), Nisyros (Greece), Nyiragongo (DRC), Masaya (Nicaragua), Gorely (Kamchatka,
Russia). We sampled leaves of different species Betulla aethnensis, Pinus nigra, Populus tremula, Senecio
aethnensis and Rumex aethnensis on Etna, Cistus creticus and salvifolius on Vulcano and Nisyros, Senecio
ssp. on Nyiragongo, a Fern on Masaya and Salix arctica at Gorely. All samples were analyzed by ICP-MS
and ICP-OES for 49 elements after acid digestion with a microwave oven (HNO3 + H2O2).
Major constituents in leaves are K, Ca, Mg, Na, Si, Al and Fe ranging from about 10 3 to 105 ppm.
Manganesium, Sr, Rb, Ba, Zn, B, Cu show also relatively high concentrations (100-103 ppm) while the
remaining elements (As, Bi, Cd, Ce, Co, Cr, Cs, Ga, Li, Mo, Ni, Pb, Sb, Sc, Se, Th, Tl, U, V, Y and lanthanide
series) display much lower values (10-4-101 ppm). Nearly all investigated elements show their highest
concentrations in the samples collected closest to the main degassing vents (open craters, fumarolic fields).
Increased concentrations are also found in the samples collected in the downwind direction where volcanic
emissions are prevailingly dispersed.
Leaves collected along radial transects from the active vents, highlight that the levels of metals decrease
from one to two orders of magnitude with increasing distance from the source. The decrease is stronger for
volatile elements, which are highly enriched in volcanic emissions, (As, Bi, Cd, Cs, Pb, Sb, Tl) than for more
refractory elements (Al, Ba, Sc, Si, Sr, Th, U). The different species of plants show significant differences in
the bioaccumulation processes for most of the analyzed elements, in particular lanthanides, which are
systematically enriched in Rumex leaves. Needles of pine (non-deciduous tree) represent a good tool for
biomonitoring investigation because they are important tracers of accumulation with time.
The high concentrations of many toxic elements in the leaves allow us to consider some of these plants as
highly tolerant species to the volcanic emissions, and suitable for biomonitoring researches further
confirming their strong potential in tracing the impact and geographic distribution of these natural
contaminants
Encefalopatia neonatale e disfunzione multiorgano, considerazioni eziologiche e correlati clinici. Valutazione di una casistica
encefalopatia neonatale, disfunzione multiorgan