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1.
Subba Rao N 《Environmental monitoring and assessment》2008,136(1-3):437-447
Trace elements are essential for human health. However, excess concentrations of these elements cause health disorders. A
study has been carried out in Visakhapatnam environs, Andhra Pradesh, India to ascertain the causes for the origin and distribution
of iron content in the groundwaters. Fifty groundwater samples are collected and analyzed for iron. The content of iron ranges
from 400 to 780 μg/l. A comparison of groundwater data with rock and soil chemistry suggests that the concentration of iron
(400–530 μg/l) in the groundwaters is derived from the rocks and soils due to geogenic processes. This concentration is taken
as a natural occurrence of iron in the groundwaters of the study area for assessing the causes for its next higher content
(>530 μg/l). Relatively higher concentration of iron (540–550 μg/l) is observed at some well waters, where the wells are located
nearby municipal wastewaters, while the very high concentration of iron (610–780 μg/l) is observed in the industrially polluted
groundwater zones, indicating the impact of anthropogenic activities on the groundwater system. These activities mask the
concentration of iron caused by geogenic origin. Hence, both the geogenic and anthropogenic activities degrade the groundwater
quality. Drinking water standards indicate that the iron content in all the groundwater samples exceeds the permissible limit
(300 μg/l) recommended for drinking purpose, causing the health disorders. Necessity of close monitoring of groundwater quality
for assessing the impact of geogenic and anthropogenic sources with reference to land use/land cover activities is emphasized
in the present study area to protect the groundwater resources from the pollution. 相似文献
2.
Melidis P Akratos CS Tsihrintzis VA Trikilidou E 《Environmental monitoring and assessment》2007,127(1-3):15-27
Thirteen field campaigns were undertaken in the period from December 2, 2002 until September 1, 2004 to collect water samples
in order to characterize the quality of rainfall and roof drainage in the city of Xanthi, a typical provincial city in Greece.
In each campaign, water samples were collected from 10 representative sites in the city (in total 130 samples), representing
areas of distinct land use and human activities (i.e., traffic volume, residence density and industrial activity). The water
samples were analyzed according to drinking water criteria for total coliform (not detected), temperature (range: 0.9–20°C),
pH (range: 3.6–11.4), alkalinity (range: 0–21.5 mg CaCO3/L), nitrate (range: 0–2456 μg/L), ammonium (range: 0–2628 μg/L), sulfate (range: 0–0.5 mg/L), calcium (range: 259.1–3064
μeq/L), magnesium (range: 0.8–488.8 μeq/L), potassium (range: 0.0–110.6 μeq/L) and dissolved heavy metals (Fe, range: 0.01–0.18
mg/L; Mn, range: 0.01–0.09 mg/L; Zn, range: 0.01–0.54 mg/L; Cu, Cr and Ni, not detected). Pollutant concentrations were generally
higher in roof drainage than in rainwater, but both were lower than drinking water standards. Dissolved heavy metal concentrations
were generally higher in the areas of intensive human activities, such as roads with high traffic volume and densely populated
residential areas. The satisfactory quality of rainwater, which results from this analysis, makes its use as grey water possible. 相似文献
3.
Modern agriculture practices reveal an increase in use of pesticides and fertilizers to meet the food demand of increasing
population which results in contamination of the environment. In India crop production increased to 100% but the cropping
area has increased marginally by 20%. Pesticides have played a major role in achieving the maximum crop production, but maximum
usage and accumulation of pesticide residues was highly detrimental to aquatic and other ecosystem. The present study was
chosen to know the level of organochlorines contamination in ground water of Thiruvallur district, Tamil Nadu, India. The
samples were highly contaminated with DDT, HCH, endosulfan and their derivatives. Among the HCH derivatives, Gamma HCH residues
was found maximum of 9.8 μg/l in Arumbakkam open wells. Concentrations of pp-DDT and op-DDT were 14.3 μg/l and 0.8 μg/l. The
maximum residue (15.9 μg/l) of endosulfan sulfate was recorded in Kandigai village bore well. The study showed that the ground
water samples were highly contaminated with organochlorine residues. 相似文献
4.
Seasonal variation of the concentrations of trace metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn) were measured by ICP-AES
in the water and sediment from the Saricay Stream, Geyik Dam and Ortakoy Well in the same basin. Comparisons between trace
metal concentrations in water and sediment in three sources (Stream, Dam and Well) were made. The concentrations of a large
number of trace metals in the water and sediment were generally higher in the Stream than in the Well and Dam, particularly
in summer. Trace metal concentration ranges in sediments of the Saricay Stream and its sources showed very wide ranges (as
mass ratio): Co: 5–476 μg g−1, Cr: 15–1308 μg g−1, Cu: 7–128 μg g−1, Fe: 1120–13210 μg g−1, Mn: 150–2613 μg g−1, Ni: 102–390 μg g−1, Pb: 0.7–31.3 μg g−1 and Zn: 18–304 μg g−1, whereas Cd was not detected. Trace metal concentration ranges found in waters were: Co: 9.5–20.7 μg L−1, Cr: 20.3–284 μg L−1, Cu: 170–840 μg L−1, Fe: 176–1830 μg L−1, Mn: 29.3–387 μg L−1, and Ni: 4.3–21.9 μg L−1. Among the trace metals studied, Cd and Zn in two seasons and Pb in winter were usually not detected or in the recommended
levels. In addition, Cd was not detected in the sediment during the winter season. The analysis of variance (one-way ANOVA)
and correlation matrix was employed for the sediment and water samples of the two field surveys (summer and winter) comparison.
The three sources showed differences in metal contents. The metal levels in sediments displayed marked seasonal and regional
variations, which were attributed to anthropogenic influences and natural processes. In the Saricay Stream, high values of
metals during the dry season showed an anthropological effect from small industry firms, e.g.: an olive mill and a dairy farm
or water dilution during summer seasons. Finally, the pollution in this basin probably originated from small industrial, low
quality coal-burned thermal power plants, and particularly agricultural and domestic waste discharges. 相似文献
5.
Yu Li Zhiming Yu Xiuxian Song Qinglin Mu 《Environmental monitoring and assessment》2006,121(1-3):489-499
Suspended particulate matter (SPM), sediments and clams were collected at three sites in Jiaozhou Bay to assess the magnitude of trace metal pollution in the area. Metal concentrations in SPM (Cu: 40.11–203; Zn: 118–447; Pb: 50.1–132; Cd: 0.55–4.39; Cr: 147.6–288; Mn: 762−1670 μg/g), sediments (Cu: 17.64–34.26; Zn: 80.79–110; Pb: 24.57–49.59; Cd: 0.099–0.324; Cr: 41.6–88.1; Mn: 343−520μg/g) and bivalves (Cu: 6.41–19.76; Zn: 35.5–85.5; Pb: 0.31–1.01; Cd: 0.51–0.67; Mn: 27.45−67.6 μg/g) are comparable to those reported for other moderately polluted world environments. SPM showed a less clear pattern. Metal concentrations in sediments displayed a clear geographical trend with values increasing with proximity to major urban centers. The clams (on dry weight) showed a complex pattern due to the variability introduced by age-related factors. Cd showed an apparent reverse industrial trend with higher concentrations in clams collected at distant stations. Zn, Pb and Mn showed no clear geographical pattern, whereas Cu increased in the clams collected in the most industrialized area. In addition, the bioaccumulation factors (BAF) were calculated. The result indicated that the studied Ruditapes philippinarum in Jiaozhou Bay possessed different bioaccumulation capacities for Cd, Zn, Cu, Pb and Mn, and Cd, Zn had a relatively high assimilation of those metals from sediment particles. A significant relationship with clam age was observed for Zn (positive) and Cu (negative) suggesting different physiological requirements for both metals with age. Trace metal concentrations measured in the tissue of the investigated clam were in the range considered safe by the WHO for human use. 相似文献
6.
In groundwater, used for drinking water supply in the greater industrial area of Thessaloniki, in Northern Greece, concentrations of total arsenic exceeded the WHO provisional guideline value and the EU maximum contaminant level (MCL) of 10 μg/L. The concentration of total arsenic was in the range between 4–130 μg/L, whereas the median value was 36 μg/L and the average concentration 46 μg/L. Nine out of the eleven wells contained total arsenic at concentration higher than 10 μg/L and it should be stressed that 6 of them contain arsenic at concentrations between 10 (new MCL) and 50 μg/L (previous MCL). The examined groundwaters were found to contain elevated concentrations of manganese and phosphate. Arsenic had a positive correlation with the pH, indicating the possible effect of pH on arsenic mobilisation. These findings emerge the problem of contamination from arsenic, since, according to the EU directive 98/83, all drinking water sources within the European Union should have achieved compliance with the new limits by 12/2003, implying that the situation requires urgent remedial action. 相似文献
7.
The objective of the study is to investigate seasonal and spatial variations of PM10 (particulate matter with aerodynamic diameter less than or equal to 10 μm) and TSP (total suspended particulate matter) of
an Indian Metropolis with high pollution and population density from November 2003 to November 2004. Ambient concentration
measurements of PM10 and TSP were carried out at two monitoring sites of an urban region of Kolkata. Monitoring sites have been selected based
on the dominant activities of the area. Meteorological parameters such as wind speed, wind direction, rainfall, temperature
and relative humidity were also collected simultaneously during the sampling period from Indian Meteorological Department,
Kolkata. The 24 h average concentrations of PM10 and TSP were found in the range 68.2–280.6 μg/m3 and 139.3–580.3 μg/m3 for residential (Kasba) area, while 62.4–401.2 μg/m3 and 125.7–732.1 μg/m3 for industrial (Cossipore) area, respectively. Winter concentrations of particulate pollutants were higher than other seasons,
irrespective of the monitoring sites. It indicates a longer residence time of particulates in the atmosphere during winter
due to low winds and low mixing height. Spread of air pollution sources and non-uniform mixing conditions in an urban area
often result in spatial variation of pollutant concentrations. The higher particulate pollution at industrial area may be
attributed due to resuspension of road dust, soil dust, automobile traffic and nearby industrial emissions. Particle size
analysis result shows that PM10 is about 52% of TSP at residential area and 54% at industrial area. 相似文献
8.
Ashraf W Seddigi Z Abulkibash A Khalid M 《Environmental monitoring and assessment》2006,117(1-3):271-279
In the present paper, seven heavy metals (Pb, Cd, Ni, Cu, Zn, Cr and Fe) in canned salmon, sardine and tuna fish were determined
by using atomic absorption spectroscopy. Cadmium and lead levels were determined by graphite tube AAS whereas Ni, Cu, Cr and
Fe were determined by flame AAS. Analytical results were validated by spiking the samples with various concentrations of these
metals for recovery. The metal contents, expressed in μg/g, wet weight, varied depending upon the specie studied. The levels
of Pb ranged from 0.03–1.20 μg-g−1 with an average of 0.313 μg-g−1 for salmon; 0.03–0.51 μg-g−1 with an average of 0.233 μg-g−1 for tuna and 0.13–1.97 μg-g−1 with an average of 0.835 μg-g−1 for sardines. The levels of Cd ranged from 0.02–0.38 μg-g−1 with an average of 0.161 μg-g−1 for salmon; 0.07–0.64 μg-g−1 with an average of 0.227 μg-g−1 for tuna and 0.010–0.690 μg-g−1 with an average of 0.183 μg-g−1 for sardines. Comparative evaluation of these metals in three varieties of fish showed that average concentration of lead
in sardines is about 4 times and Ni about 3 times higher as compared to tuna. Generally, the levels of these metals follow
the order sardine > salmon > tuna. The data generated in the present study compared well with the similar studies carried
out in different parts of the world. The results indicate that canned fish, in general and tuna in particular, have concentrations
within permissible limits of WHO/FAO levels for these heavy metals. Therefore, their contribution to the total body burden
of these metals can be considered as negligibly small. 相似文献
9.
Alam JB Hossain A Khan SK Banik BK Islam MR Muyen Z Rahman MH 《Environmental monitoring and assessment》2007,134(1-3):233-242
Surma River is polluted day by day by human activities, poor structured sewerage and drainage system, discharging industrial
and household wastes. The charas (natural channels) are responsible for surface runoff conveyance from its urban catchments
to the receiving Surma River. Water samples have been collected from a part of Surma River along different points and analyzed
for various water quality parameters during dry and monsoon periods. Effects of industrial wastes, municipal sewage, and agricultural
runoff on river water quality have been investigated. The study was conducted within the Chattak to Sunamganj portion of Surma
River, which is significant due to the presence of two major industries – a paper mill and a cement factory. The other significant
feature is the conveyors that travel from India to Chattak. The river was found to be highly turbid in the monsoon season.
But BOD and fecal coliform concentration was found higher in the dry season. The water was found slightly acidic. The mean
values of parameters were Conductivity 84–805 μs; DO: dry-5.52 mg/l, monsoon-5.72 mg/l; BOD: dry-1mg/l, monsoon-0.878 mg/l;
Total Solid: dry-149.4 mg/l, monsoon-145.7 mg/l. In this study, an effort has been taken to investigate the status of concentration
of phosphate (PO−4) and ammonia–nitrogen (NH4–N) at four entrance points of Malnichara to the city, Guali chara, Gaviar khal and Bolramer khal. Data has been collected
from March–April and September–October of 2004. Concentrations have been measured using UV Spectrophotometer. Although the
phosphate concentration has been found within the limit set by DOE for fishing, irrigation and recreational purposes, however
ammonia–nitrogen has been found to exceed the limit. 相似文献
10.
Advances in research on pollution of organic pesticides (OPs) in surface water, pollution survey and risk assessments of organochlorine
pesticides (OCPs) and organophosphorus pesticides (OPPs) of surface water in Hangzhou are conducted. Total concentrations
of dichloro-diphenyl-trichloroethane (DDT) and hexachloride-benzene (HCH) in surface water were observed to be 0–0.270 μg/L
and 0–0.00625 μg/L respectively. DDE, as a metabolite of DDT and many species of OPPS were determined in some samples of surface water. Parathion, the main pollutant among OPPs in surface water of Hangzhou,
was observed to be 0–0.445 μg/L. Based on these experimental results, health risk assessments on the organic pollution are
developed. It is observed that the total risk “R
T” at present time of surface water in Hangzhou is mainly contributed by organophosphorus pesticides, especially Parathion;
HCH and DDT are not the main contaminants; on the contrary, organophosphorous pesticides, especially Parathion, must be of
concern at the present time. 相似文献
11.
In this study, the relationship between some physico-chemical properties of soils and lead contamination in soil due to emission
from industrial operations in Samsun province of Turkey was investigated. The extent of timely contamination was studied by
comparing the obtained results with the results of the study conducted in the same region in 1998. An area of 225 km2 (15 km × 15 km), which was divided into 1000 × 1000 m grid squares (16 lines in the east and south directions), was selected
within the industrial area. The total of 256 grid points was obtained and soil samples were collected from three depths (0–5,
5–15, and 15–30 cm) of each grid center in 2004. The total Pb concentrations of soil samples were determined as 65.84–527.04
μg g−1 at 0–5 cm in depth, 58.50 – 399.54 μg g−1 at 5–15 cm in depth, and 44.65–330.07 μg g−1 at 15–30 cm in depth. DTPA-extractable Pb concentrations of soils were found to be in the range of 1.52–9.03 μg g−1, 0.54–7.09 μg g−1, 0.19–6.13 μg g−1 at 0–5, 5–15, and 15–30 cm depths, respectively. There were significant relationships between both total or DTPA-extractable
Pb concentrations and selected physico-chemical properties of soil. According to enrichment factor (EF) values calculated
from the total Pb concentrations, 11.3% of the study area (225 km2) was enriched with Pb in high level, but 77% of the area was in significant enrichment level with Pb. The average total and
DTPA-extractable Pb concentrations increased as 11 and 13%, respectively in comparison with the results of 1998. 相似文献
12.
Twelve samples each of soil and ground water were collected from paddy-wheat, paddy-cotton, sugarcane fields and tube wells
from same or near by fields around Hisar, Haryana, India during 2002–2003 to monitor pesticide residues. Residues were estimated
by GC-ECD and GC-NPD systems equipped with capillary columns for organochlorine, synthetic pyrethroid and organophosphate
insecticides. In soil, HCH (0.002–0.051 μg g−1), DDT (0.001–0.066 μg g−1), endosulfan (0.002–0.039 μg g−1) and chlordane (0.0002–0.019 μg g−1) among organochlorines, cypermethrin (0.001–0.035 μg g−1) and fenvalerate (0.001–0.022 μg g−1) among synthetic pyrethroids and chlorpyriphos (0.002–0.172 μg g−1), malathion (0.002–0.008 μg g−1), quinalphos (0.001–0.010 μg g−1) among organophosphates were detected. Dominant contaminants were DDT, cypermethrin and chlorpyriphos from the respective
groups. In water samples, HCH, DDT, endosulfan and cypermethrin residues were observed frequently. Only chlorpyriphos among
organophosphates was detected in 10 samples. On consideration of tube well water for drinking purpose, about 80% samples were
found to contain residues above the regulatory limits. 相似文献
13.
Sunlu U 《Environmental monitoring and assessment》2006,114(1-3):273-286
Bio-monitoring of some heavy metal levels (Cd, Pb, Zn, Cu) in whole edible soft parts of Mytilus galloprovincialis (L. 1758) was conducted in Turkish Aegean Sea coast during the period of September 2002–August 2003 seasonally. Moreover, some physico-chemical environmental parameters, also have been analysed in the same region. The values of some physico-chemical environmental parameters in coastal waters of Turkish Aegean Sea were changed between; 9.0–27.0 ∘C for temperature, 31.93–40.45 psu for salinity, 7.35–8.48 for pH and 4.05–9.50 mg/l for dissolved oxygen. The levels of trace elements in whole edible soft parts including interstitial fluids of Mediterranean mussels M. galloprovincialis (L. 1758), sampled from 6 different regions of Turkish Aegean Sea coast have ranged between; 0.04–0.52 μg Cd/g wet weight, 0.49–1.72 μg Pb/g w.w., 0.95–1.85 Cu/g w.w., 16.11–37.15 μg Zn/g w.w. The highest values for all trace metals (Cd, Pb, Zn, Cu) were measured in inner part of Izmir Bay (station 3) and lowest in Sigacik and Gulluk Bay (station 5, 6). Generally heavy metal levels are lower than the results in soft mussel tissues reported from Mediterranean regions. 相似文献
14.
Physico-chemical characteristics of some river and hand-dug well waters used for drinking and domestic purposes in the oil
rich Niger Delta area of Nigeria were assessed using standard methods. The concentrations of the parameters in the river water
samples ranged in the following order: pH (5.6–6.9), temperature (26.90–28.60°C), turbidity (23–63 NTU), electrical conductivity
(52–184 μs/cm), DO (5.4–7.2 mg/l), BOD (21–57 mg/l), TDS (6.0–217 mg/l), PO4
3− (0.19–1.72 mg/l), SO4
2− (25–36.8 mg/l), NO3
− (20.3–28 mg/l), Fe (6.07–15.71 mg/l), Zn (0.04–0.24 mg/l), Pb (0.01–0.17 mg/l), Ni (0.01–0.13 mg/l), Vn (0.01–0.20 mg/l)
and Hg (0.001–0.002 mg/l). The concentrations of these parameters in the hand-dug well water ranged in the following order:
pH (5.7–6.8) temperature (26–30°C), turbidity (134–171 NTU), electrical conductivity (160–340 μs/cm), DO (5.4–6.4 mg/l), BOD
(13–34 mg/l), TDS (110–190 mg/l), PO4
3− (0.84–1.84 mg/l), SO4
2− (10.6–28.1 mg/l), NO3
− (11.3–23 mg/l), Fe (13.17–16.31 mg/l), Ni (0.01–0.02 mg/l), Vn (0.01–0.04 mg/l) and Hg (0.001–0.004 mg/l). The concentrations
of BOD, turbidity, NO3
− and Fe in the water samples were above WHO and FMENV permissible limits for safe drinking water. The results suggest that
the use of such waters for drinking and domestic purposes pose a serious threat to the health of the users and calls for the
intervention of government agencies. 相似文献
15.
Concentrations of heavy metals were determined in the water column (including the sea-surface microlayer, subsurface, mid-depth
and bottom water) and sediments from Singapore’s coastal environment. The concentration ranges for As, Cd, Cr, Cu, Ni, Pb
and Zn in the seawater dissolved phase (DP) were 0.34–2.04, 0.013–0.109, 0.07–0.35, 0.23–1.16, 0.28–0.78, 0.009–0.062 and
0.97–3.66 μg L−1 respectively. The ranges for Cd, Cr, Cu, Ni, Pb and Zn in the suspended particulate matter (SPM) were 0.16–0.73, 6.72–53.93,
12.87–118.29, 4.34–60.71, 1.10–6.08 and 43.09–370.49 μg g−1, respectively. Heavy metal concentrations in sediments ranged between 0.054–0.217, 37.48–50.52, 6.30–21.01, 13.27–26.59,
24.14–37.28 and 48.20–62.36 μg g−1 for Cd, Cr, Cu, Ni, Pb and Zn, respectively. The lowest concentrations of metals in the DP and SPM were most frequently found
in the subsurface water while the highest concentrations were mostly observed in the SML and bottom water. Overall, heavy
metals in both the dissolved and particulate fractions have depth profiles that show a decreasing trend of concentrations
from the subsurface to the bottom water, indicating that the prevalence of metals is linked to the marine biological cycle.
In comparison to data from Greece, Malaysia and USA, the levels of metals in the DP are considered to be low in Singapore.
Higher concentrations of particulate metals were reported for the Northern Adriatic Sea and the Rhine/Meuse estuary in the
Netherlands compared to values reported in this study. The marine sediments in Singapore are not heavily contaminated when
compared to metal levels in marine sediments from other countries such as Thailand, Japan, Korea, Spain and China. 相似文献
16.
Enrichment and fractionation of heavy metals in bed sediments of River Narmada, India 总被引:2,自引:0,他引:2
A metal fractionation study on bed sediments of River Narmada in Central India has been carried out to examine the enrichment
and partitioning of different metal species between five geochemical phases (exchangeable fraction, carbonate fraction, Fe/Mn
oxide fraction, organic fraction and residual fraction). The river receives toxic substances through a large number of tributaries
and drains flowing in the catchment of the river. The toxic substances of particular interest are heavy metals derived from
urban runoff as well as municipal sewage and industrial effluents. Heavy metals entering the river get adsorbed onto the suspended
sediments, which in due course of time settle down in the bottom of the river. In this study fractionation of metal ions has
been carried out with the objective to determine the eco-toxic potential of metal ions. Although, in most cases (except iron)
the average trace/heavy metal concentrations in sediments were higher than the standard shale values, the risk assessment
code as applied to the present study reveals that only about 1–3% of manganese, <1% of copper, 16–19% of nickel, 4–20% of
chromium, 1–4% of lead, 8–13% of cadmium and 1–3% of zinc exist in exchangeable fraction and therefore falls under low to
medium risk category. According to the Geo-accumulation Index (GAI), cadmium shows high accumulation in the river sediments,
rest of other metals are under unpolluted to moderately polluted class. 相似文献
17.
We conducted a laboratory evaluation to assess the risk to early life stage (i.e., eyed egg to swim up) fall Chinook salmon
(Oncorhynchus tshawytscha) for exposure to hexavalent chromium from a contaminated groundwater source. Local populations of fall Chinook salmon were
exposed to Hanford Site source groundwater that was diluted with Columbia River water. Specific endpoints included survival,
development rate, and growth. Tissue burdens of fish were also measured to estimate uptake and elimination rates of chromium.
Survival, development, and growth of early life stage fall Chinook salmon were not adversely affected by extended exposures
(i.e., 98 day) to hexavalent chromium ranging from 0.79 to 260 μg/l. Survival for all treatment levels and controls exceeded
98% at termination of the test. In addition, there were no differences among the mean lengths and weights of fish among all
treatment groups. Whole-body concentrations of chromium in early life stage fall Chinook salmon had a typical dose-response
pattern; i.e., those subjected to highest exposure concentrations and longest exposure intervals had higher tissue concentrations.
Given the spatial extent of chromium concentrations at the Hanford Site, and the dynamics of the groundwater–river water interface,
the current cleanup criterion of 10 μg/l chromium appear adequate to protect early life stage fall Chinook salmon. These findings,
together with previous research indicate low risk to these populations. 相似文献
18.
Kimmo Louekari R. Mäkelä-Kurtto P. Jousilahti 《Environmental Modeling and Assessment》2008,13(4):517-525
We have assessed the change of the dietary intake and the potential health risks of cadmium in Finland, assuming that a high
level of cadmium in fertilizers (138 mg Cd/kg P) would prevail for the next 100 years. Soil measurements and modelling were
used to derive the predicted level of cadmium in foods. In three important cultivars, wheat, potato and sugar beet, the cadmium
concentration would increase by 20–35%. Consequently, the average dietary intake of cadmium in Finland would increase from
7.9 to 10.0 μg/day, corresponding with the urinary level of about 0.2 μg/l, a level that has not been associated with effects
on the human health. However, in the risk group with 1) high dietary intake of cadmium, 2) elevated gastrointestinal absorption,
and 3) tobacco smoking, the estimated urinary level of cadmium would be 2.0 μg/l. Recent epidemiological studies have shown
that urinary level of 1–2 μg Cd/l is associated with an increased risk of bone demineralization and fractures, and 2–4 μg
Cd/l with pre-clinical kidney damage. People characterized by more than one of the above-mentioned risks factors, may develop
the adverse health effects at an old age, when cadmium has accumulated in the body. 相似文献
19.
This is the first study related to the effects of cadmium (Cd) on the development and hatching of eggs of Loligo vulgaris. The eggs were exposed to concentrations varying from 10 to 100,000 μg Cd/l for up to 1 month. During the study period natural
sea water salinity (37 PSU), ambient temperature (ranging 16.5–21.5°C) and light conditions of 12-h light: 12-h dark for 744-h
were used prior to the hatching. For 96-h, mortality rate of 100% of the eggs was found at cadmium concentration of 100,000 μg
Cd/l, and the same mortality rate of the eggs were found at 1,000 and 10,000 μg Cd/l for 744-h and 696-h, respectively. Hatching
took place between hours 456 and 576 in the control group and between hours 480 and 576 in 10 and 100 μg Cd/l groups. Total
hatching rates were calculated to be 98.2 ± 1.6% for control group, 99.4 ± 0.6% for 10 μg Cd/l group and 98.6 ± 1.2% for 100 μg
Cd/l group. Hatching successes were estimated as 69.5 ± 13.8% for control group, 84.5 ± 8.2% for 10 μg Cd/l group and 76.9 ± 5.9%
for 100 μg Cd/l group. In the 100,000 μg Cd/l treatment, the egg degeneration began from animal pole of the eggs in 16 h,
and 50% and 100% of them died in the initial stage at 72-h and 96-h, respectively. In the 10,000 μg Cd/l group, the eggs which
reached at stage 19 (IX) were deformed and 50% and 100% of them died at 312-h and 696-h, respectively. In 1,000 μg Cd/l group,
however, the eggs developed abnormally from stage 21 (X–XI) and reached at stage 29 (XIX), and 50% and 100% of them died in
624-h and in 744-h, respectively. There were significant differences in survival rates of the eggs among the concentrations
(p < 0.05). The current study demonstrated that Cd adversely affects the development, survival and hatching of L. vulgaris eggs; however, no mortality was observed in 10 μg Cd/l and 100 μg Cd/l groups. 相似文献
20.
Assessment of water pollution in different bleaching based paper manufacturing and textile dyeing industries in India 总被引:3,自引:0,他引:3
Paper industries using different raw materials such as hard wood, bamboo, baggase, rice-straw and waste papers and bleaching
chemicals like chlorine, hypochlorite, chlorine dioxide, hydrogen peroxide, sulphite and oxygen were studied to estimate organic
pollution load and Adsorbable Organic Halides (AOX) per ton of production. The hard wood based paper industries generate higher
Chemical Oxygen Demand (COD) loads (105–182 kg t−1) and Biochemical Oxygen Demand (BOD) loads (32.0–72 kg t−1) compared to the agro and waste paper based industrial effluents. The bleaching sequences such as C–EP–H–H, C–E–H–H, C–E–Do–D1
and O–Do–EOP–D1 are adopted in the paper industries and the molecular elemental chlorine free bleaching sequence discharges
low AOX in the effluent. The range of AOX concentration in the final effluent from the paper industries was 0.08–0.99 kg t−1 of production. Water consumption was in the range of 100–130 m3 t−1 of paper production for wood based industries and 30–50 m3 for the waste paper based industries. Paper machine effluents are partially recycled after treatment and pulp mill black
liquor are subject to chemical recovery after evaporation to reduce the water consumption and the total pollution loads. Hypochlorite
bleaching units of textile bleaching processes generate more AOX (17.2–18.3 mg l−1) and are consuming more water (45–80 l kg−1) whereas alkali peroxide bleaching hardly generates the AOX in the effluents and water consumption was also comparatively
less (40 l kg−1 of yarn/cloth). 相似文献