Σήμερα είναι επίκαιρο να δούμε το θέμα των ναυπηγείων και των καρνάγιων σε σχέση με την ρύπανση που προκαλούν.
Η διεθνής βιβλιογραφία βρίθει παραδειγμάτων!
The 180 ship recycling yards located on Alang-Sosiya beach in the State
of Gujarat on the west coast of India is the world's largest cluster
engaged in dismantling. Yearly 350 ships have been dismantled (avg.
10,000 ton steel/ship) with the involvement of about 60,000 workers.
Cutting and scrapping of plates or scraping of painted metal surfaces
happens to be the commonly performed operation during ship breaking. The
pollutants released from a typical plate-cutting operation can
potentially either affect workers directly by contaminating the
breathing zone (air pollution) or can potentially add pollution load
into the intertidal zone and contaminate sediments when pollutants get
emitted in the secondary working zone and gets subjected to tidal
forces. There was a two-pronged purpose behind the mathematical modeling
exercise performed in this study. First, to estimate the zone of
influence up to which the effect of plume would extend. Second, to
estimate the cumulative maximum concentration of heavy metals that can
potentially occur in ambient atmosphere of a given yard. The cumulative
maximum heavy metal concentration was predicted by the model to be
between 113 μg/Nm(3) and 428 μg/Nm(3) (at 4m/s and 1m/s near-ground wind
speeds, respectively). For example, centerline concentrations of lead
(Pb) in the yard could be placed between 8 and 30 μg/Nm(3). These
estimates are much higher than the Indian National Ambient Air Quality
Standards (NAAQS) for Pb (0.5 μg/Nm(3)). This research has already
become the critical science and technology inputs for formulation of
policies for eco-friendly dismantling of ships, formulation of ideal
procedure and corresponding health, safety, and environment provisions.
The insights obtained from this research are also being used in
developing appropriate technologies for minimizing exposure to workers
and minimizing possibilities of causing heavy metal pollution in the
intertidal zone of ship recycling yards in India.
Ecological Risk Posed by Heavy Metals Contamination of Ship BreakingYards in Bangladesh
Pollution of water and soils by heavy metals is an emerging problem in industrialized countries.
The present study was conducted to investigate the heavy metals concentration in water and sediment
samples from ship breaking sites of Sitakunda to assess the potential ecological risk posed by heavy metal
using different methods. Heavy metals concentration was analyzed by Atomic Absorption Spectroscopy.
Concentrations
of all the tested heavy metals except Cr in water samples of ship
breaking site, Sitakunda were lower than recommended values. The mean
concentration of Cr was found 0.511± 0.284 mg/l. Concentrations of all
the tested heavy metals except Mn in sediment samples were higher than
standard limit. The concentrations of Pb, Mn, Cr, Cu and Zn in the
sediment were 55.93±18.70, 20.08±4.03, 106.8±47.65, 50.09±18.31, and
70.71±19.45 mg/kg, respectively. Based on Geoaccumulation Index,
Contamination factor, Sediment Quality Guidelines, the sediment of ship
breaking site can be treated as unpolluted to moderately polluted with
Pb, Zn, Cr and Cu but unpolluted with Mn. The Enrichment factors of Pb,
Mn, Cr, Cu and Zn in the sediment were: 2.97±0.98, 0.035±0.008,
1.97±0.88, 1.99±0.73, and 1.17±0.32, respectively. The Enrichment factor
(>1) in all sampling sites, suggesting source of those metals (Pb,
Cr, Cu and Zn) were more likely to be anthropogenic. Based on the
Potential Ecological Risk Index the ship breaking site posed to low risk
to the environment. The results of present study clearly indicated that
the ship breaking site was moderately polluted with heavy metals and
pose low risk to the ecosystem.
Distribution of Heavy Metals in Surface Sediments of the Bay of Bengal Coast
The concentrations of major (Si, Al, Ca, Fe, and K) and minor (Cd, Mn,
Ni, Pb, U, Zn, Co, Cr, As, Cu, Rb, Sr, and Zr,) elements in the
surficial sediments were studied in an attempt to establish their
concentration in the Bengal coast. It was revealed that the majority of
the trace elements have been introduced into the Bengal marine from the
riverine inflows that are also affected by the impact of industrial,
ship breaking yard, gas production plant, and urban wastes. The
concentration of heavy metals was measured using Atomic Absorption
Spectroscopy and Energy Dispersive X-ray fluorescence instruments. The
highest concentrations for several trace elements were thus recorded
which generally decrease with distance from the coast. It was observed
that the heavy metal concentrations in the sediments generally met the
criteria of international marine sediment quality. However, both the
contamination factor and pollution load index values suggested the
elevation of some metals’ concentrations in the region. Constant
monitoring of the Bengal coast water quality needs to be recorded with a
view to minimizing the risk of health of the population and the
detrimental impacts on the aquatic ecosystem.
Γιατί τα πλοία είναι τοξικά? Why ships are toxic?
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