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1.
Paul R. D. Wright Robin Rattray Gerald Lalor Richard Hanson 《Environmental geochemistry and health》2010,32(6):567-581
Elevated concentrations of naturally occurring Cd have been found mainly in the bauxitic soils of central Jamaica at levels
up to 100–1,000 times higher than typical worldwide averages. Some food crops cultivated on these soils absorb significant
amounts of Cd. Autopsy studies of kidney Cd concentrations confirm elevated human exposure, and some long-term residents in
central Jamaica exceed the general population average by a factor of two. Diet studies have ascertained that a population
in central Jamaica is at risk of being exposed to Cd levels in excess of the Provisional Tolerable Weekly Intake (PTWI) set
by the WHO of 7 μgCd/kg bodyweight/week, and the EU TWI of 2.5 μgCd/kg bodyweight/week. Elevated levels of urine cadmium (U-Cd)
and beta-2 microglobulin (β2-MG) concentrations were confirmed with a strong correlation between soil Cd and the U-Cd. Also,
higher β2-MG concentrations (>200μg/g creatinine) were found in the population with U-Cd concentrations greater than 2.5μg/L.
While this identification is often taken to indicate impairment in the reabsorption capacity of the renal tubules leading
to renal disease, there is no evidence in the mortality records of enhanced deaths in central Jamaica compared with the general
population resulting from renal disease or diabetes related complications. The highest median age of death in the island is
found in Manchester, the parish with the highest average Cd concentration. While we have identified a possible Cd linked renal
dysfunction, significant indications of morbidity are not present in the general population. 相似文献
2.
Debapriya Mondal Mayukh Banerjee Manjari Kundu Nilanjana Banerjee Udayan Bhattacharya Ashok K. Giri Bhaswati Ganguli Sugata Sen Roy David A. Polya 《Environmental geochemistry and health》2010,32(6):463-477
Remediation aimed at reducing human exposure to groundwater arsenic in West Bengal, one of the regions most impacted by this
environmental hazard, are currently largely focussed on reducing arsenic in drinking water. Rice and cooking of rice, however,
have also been identified as important or potentially important exposure routes. Quantifying the relative importance of these
exposure routes is critically required to inform the prioritisation and selection of remediation strategies. The aim of our
study, therefore, was to determine the relative contributions of drinking water, rice and cooking of rice to human exposure
in three contrasting areas of West Bengal with different overall levels of exposure to arsenic, viz. high (Bhawangola-I Block,
Murshidibad District), moderate (Chakdha Block, Nadia District) and low (Khejuri-I Block, Midnapur District). Arsenic exposure
from water was highly variable, median exposures being 0.02 μg/kg/d (Midnapur), 0.77 μg/kg/d (Nadia) and 2.03 μg/kg/d (Murshidabad).
In contrast arsenic exposure from cooked rice was relatively uniform, with median exposures being 0.30 μg/kg/d (Midnapur),
0.50 μg/kg/d (Nadia) and 0.84 μg/kg/d (Murshidabad). Cooking rice typically resulted in arsenic exposures of lower magnitude,
indeed in Midnapur, median exposure from cooking was slightly negative. Water was the dominant route of exposure in Murshidabad,
both water and rice were major exposure routes in Nadia, whereas rice was the dominant exposure route in Midnapur. Notwithstanding
the differences in balance of exposure routes, median excess lifetime cancer risk for all the blocks were found to exceed
the USEPA regulatory threshold target cancer risk level of 10−4–10−6. The difference in balance of exposure routes indicate a difference in balance of remediation approaches in the three districts. 相似文献
3.
The cancer risk and the non-cancer hazard index for inhabitants exposed to As, Cd, Cu and Zn in the soils and stream waters
of the abandoned Songcheon Au–Ag mine area were evaluated. Mean concentrations of As, Cd, Cu, Pb and Zn in agricultural soils
were 230, 2.5, 120, 160, and 164 mg kg−1, respectively. Mean concentrations of As, Cd and Zn of the water in the stream where drinking water was drawn was 246 μg
L−1, 161 μg L−1 and 3899 μg L−1, respectively. These levels are significantly higher than the permissible levels for drinking water quality recommended by
Korea and WHO. The resulting human health risks to farmers who inhabited the surrounding areas due to drinking water were
summarized as follows: (1) the non-cancer health hazard indices showed that the toxic risk due to As and Cd in drinking water
were 10 and 4 times, respectively, greater than those induced by the safe average daily dosages of the respective chemicals.
(2) the cancer risk of As for exposed individuals through the drinking water pathway was 5 in 1000, exceeded the acceptable
risk of 1 in 10,000 set for regulatory purposes. 相似文献
4.
The use of tree species for phytoremediation of contaminated soil offers the advantage of a large biomass in which to store
contaminants. We investigated the cadmium (Cd) and zinc (Zn) accumulation ability of Evodiopanax innovans, a common deciduous tree species belonging to the Araliaceae family and widely found in secondary forests in Japan. Sampling
was conducted at an old silver mine. Leaf samples were collected from nine tree species, including E. innovans. The seasonal variation of metal concentrations in the leaves and the detailed distribution of metals in the leaves and twigs
of E. innovans were measured. We also analyzed the contents of organic acids in the leaves. The highest concentration of Cd in the leaves
of E. innovans was 118 μg/g, which exceeds the threshold level for being considered a Cd hyperaccumulator (100 μg/g). For Zn, the highest
value was 1040 μg/g in leaves, which is less than required to qualify as a Zn hyperaccumulator. Both Cd and Zn were found
to accumulate in the petioles and veins of leaves and the bark of twigs. Since the oxalic acid content of leaves showed a
weak correlation with Cd concentration, oxalic acid may play an important role in the accumulation of Cd. Taking both the
Cd concentration level and the biomass of this woody plant into consideration, it may be possible to use E. innovans for the phytoremediation of Cd-contaminated soils. 相似文献
5.
Cadmium levels in Europe: implications for human health 总被引:5,自引:0,他引:5
Jilang Pan Jane A. Plant Nikolaos Voulvoulis Christopher J. Oates Christian Ihlenfeld 《Environmental geochemistry and health》2010,32(1):1-12
In this study we used the Forum of European Geological Surveys geochemical baseline data to examine the distribution of cadmium
(Cd) in Europe, with a particular reference to the international soil and water guideline values. The highest cadmium levels
were found to occur in topsoil and to follow closely the distribution of P2O5, suggesting that the contamination was from the use of rock phosphate fertilizer in intensive arable agriculture. In terms
of human health impacts, food (up to several hundred μg/day) was found as the only major route of exposure to Cd for the non-smoking
general population. It appeared that low levels of chronic exposure to Cd resulted in completely different human health impacts
than those high levels that had caused the ‘itai–itai’ disease. Some correlations were suggested between cadmium levels and
the age-adjusted prostate or breast cancer rates distributed in the European countries under study. 相似文献
6.
The influence of naturally occurring uraniferous black shales on cadmium, molybdenum and selenium concentrations in soils
and plants is examined. The possible implications of element concentrations to animal and human health are considered for
the Deog-Pyoung area.
Geochemical surveys have been undertaken within 13 river tributary valleys in the area underlain by uraniferous black shales
and black slates or grey chlorite schists. Sampling of rocks, soils and plants has been carried out along transect lines within
each valley. Samples were analysed for trace elements by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES)
and for uranium by Neutron Activation Analysis (NAA). Soil pH, cation exchange capacity, loss on ignition and particle size
distribution have been measured for selected samples.
Average trace element concentrations of the Okchon uraniferous black shales were 6.3 μg g−1 Cd, 136 μg g−1 Mo and 8.6 μg g−1 Se. Soils derived from these rocks tend to reflect their extreme geochemical composition. Trace element concentrations in
alluvial soils derived in part from these black shales averaged 1.2 μg g−1 Cd, 20 μg g−1 Mo and 1.5 μg g−1 Se. Trace element concentrations in plants were found to be influenced by those of soils. Cadmium accumulated in tobacco
leaves up to 46 μg g−1 (D.M.) and leafy plants such as lettuce contain up to 0.5 μg g−1 Se (D.M.).
In addition to total concentrations in soils, soil pH is a major factor influencing uptake of Mo into crop plants and soil
texture for Se. Concentrations of trace elements in plants also varied between plant species. The relative concentrations
of Cd were found to vary in the order tobacco > lettuce > red pepper > rice grain.
Elevated concentrations of Cd in crop plants and in tobacco may possibly have deleterious effects on human health in this
area. The low Cu:Mo ratio in rice stalk of 2.65:1 may be associated with disturbed Cu metabolism in ruminant animals which
regularly consume this material. 相似文献
7.
E. Gould R. J. Thompson L. J. Buckley D. Rusanowsky G. R. Sennefelder 《Marine Biology》1988,97(2):217-223
Sea scallops Placopecten magellanicus in early gametogenesis from the southern shelf of Hudson Canyon, New Jersey, USA, were exposed in late winter 1984 to sublethal levels of Cu and Cd in a flowing seawater system at the NMFS Milford Laboratory. Exposure was to copper (10 and 20 gl-1: low-Cu and high-Cu groups) or to a combination of copper and equimolar cadmium (10g Cu+17.7 g Cdl-1: low-Cu/Cd group) for eight weeks, with sampling at 2-wk intervals. Copper had a strongly inhibitory effect on gamete production and maturation, which in some respects was partially moderated in the presence of cadmium in the female gonad only. Total gamete weight per scallop doubled in control individuals but dropped by 60% in both high-metal exposure groups over the 8-wk exposure period, with a smaller, temporary decrease in the low-Cu group. Cadmium did not add to the inhibition by copper of gamete development in the low-Cu/Cd group, but there was no partial recovery at 8 wk, as was seen in female scallops exposed to low-Cu alone. Gonadal RNA, higher in the females, decreased proportionately more in that sex than in the males of the metal exposure groups. Conversely, DNA levels were higher in the male than in the female gonad, and decreased sharply in all metal-exposed males. Gonadal protein concentration also dropped in all metal-exposed scallops with time and degree of metal exposure. Copper uptake in the gonad increased with time and metal exposure concentration, and cadmium increased in the low-Cu/Cd group with time. In contrast, manganese decreased significantly in the gonads of Cu-exposed scallops, especially in the high-Cu group. In the low-Cu/Cd group, manganese concentrations stabilized after an initial sharp drop at 2 wk in the low-Cu/Cd group, then rose at 6 and 8 wk. We ascribe this phenomenon to the induction by cadmium of metal-binding proteins (Fowler and Megginson 1986). In both sexes, gonadal magnesium concentrations did not change with increasing tissue burdens of copper and cadmium, but instead rose initially in proportion to the degree of metal exposure, homeostasis being maintained thereafter. 相似文献
8.
Asaad Ahmed Nafees Ambreen Kazi Zafar Fatmi Muhammad Irfan Arif Ali Fujio Kayama 《Environmental geochemistry and health》2011,33(2):203-216
This study was designed to determine the association between chronic arsenic exposure through drinking groundwater and decrement
in lung function, particularly among individuals who do not have signs of arsenic lesions, among an adult population. This
was a comparative cross-sectional study conducted during the months of January to March 2009. One hundred participants ≥15 years
of age in each group, i.e. exposed (≥100 μg/l) and unexposed (≤10 μg/l) to arsenic, determined by testing drinking water samples
(using portable kits), were compared for effects on lung function using spirometry. A structured and validated questionnaire
was administered. Examination for arsenic skin lesions was also done. There was a decline in the mean adjusted FEV1 of 154.3 ml
(95% CI: −324.7, 16.0; p = 0.076), in mean adjusted FVC of 221.9 ml (95% CI: −419.5, −24.3; p = 0.028), and in FEV1/FVC ratio of 2.0 (95% CI: −25.3, 29.4; p = 0.884) among participants who were exposed to arsenic compared to those unexposed. A separate model comprising a total
of 160 participants, 60 exposed to arsenic concentrations ≥250 μg/l and 100 unexposed at arsenic concentrations of ≤10 μg/l,
showed a decrement in mean adjusted FEV1 of 226.4 ml (95% CI: −430.4, −22.4; p = 0.030), in mean adjusted FVC of 354.8 ml (95% CI: −583.6, −126.0; p = 0.003), and in FEV1/FVC ratio of 9.9 (95% CI: −21.8, 41.6; p = 0.539) among participants who were exposed to arsenic in drinking groundwater. This study demonstrated that decrement in
lung function is associated with chronic exposure to arsenic in drinking groundwater, occurring independently, and even before
any manifestation, of arsenic skin lesions or respiratory symptoms. The study also demonstrated a dose-response effect of
arsenic exposure and lung function decrement. 相似文献
9.
Yujie Pan Yalan Li Hongxia Peng Yiping Yang Min Zeng Yang Xie Yao Lu Hong Yuan 《Frontiers of Environmental Science & Engineering》2023,17(5):56
10.
The effect of cadmium on antioxidant responses and the susceptibility to oxidative stress in the hydrothermal vent mussel Bathymodiolus azoricus 总被引:1,自引:0,他引:1
Rui Company Angela Serafim Richard Cosson Lionel Camus Bruce Shillito Aline Fiala-Médioni Maria João Bebianno 《Marine Biology》2006,148(4):817-825
Hydrothermal vents are a unique environment of extreme physical–chemical characteristics and biological species composition.
Cd is a toxic non-essential metal present in high concentrations in the hydrothermal vent environment, contrary to those found
in marine coastal areas. Cd toxicity has been related, among other things, with reactive oxygen species production, even though
this is a non-redox metal. Bathymodiolus azoricus is a deep-sea Mytilid bivalve very common in the Mid Atlantic Ridge (MAR) hydrothermal vent fields and very little is known
about the antioxidant defence system in this specie. Because lethal Cd concentration in B. azoricus is unknown, the aim of this study was to assess the effects of a Cd concentration higher than that found in the hydrothermal
vents on oxidative stress biomarkers, such as antioxidant enzymes. Mussels were exposed to 100 μg l−1 Cd during 24, 48 and 144 h, respectively, in a pressurized aquarium (IPOCAMP). Superoxide dismutase (SOD), catalase (CAT),
glutathione peroxidases (GPx), total oxyradical scavenging capacity (TOSC), metallothionein (MT) and lipid peroxidation (LPO)
were measured in the gills and mantle of B. azoricus. The results indicate that gills are first affected by Cd toxicity. This may be due to different physiological functions
of the tissues and by the presence of thio and methanotrophic symbiotic bacteria in the gills. The SOD and CAT are inhibited
during the first day of exposure in the gills, although TOSC and MT concentrations were the same in control and exposed mussels.
In the mantle, enzymatic activation only occurred after 6 days, and no significant differences in MT concentrations were found
in the control and exposed mussels during the first day, as observed in the gills. 相似文献
11.
Transport of cadmium and other metals in the blood of the bivalve mollusc Mercenaria mercenaria 总被引:1,自引:0,他引:1
The distribution of metals (Ba, Cr, Cu, Fe, Mn, Ni and Zn) in the blood plasma and the circulating hemocytes was determined for a eulamellibranch bivalve, the quahog Mercenaria mercenaria (L.), collected from a relatively clean site at Falmouth, Massachusetts, USA. Whole blood volume was an exponential function of quahog length (Y=5.71×10-5 X3.0678; Y=ml of whole blood; X=mm length). Of this volume, 1.2±0.3% (
) was attributable to blood cells. Total metal content (g metal, or g metal normalized per g of whole blood) was much higher in blood plasma than in hemocytes. In quahogs exposed in the laboratory to 100 ppb 109Cd, 93.0% of the total accumulated blood Cd was in the plasma rather than in the circulating hemocytes (7.0%), irrespective of the length of exposure (1 h to 31 d). Less than 5% of the plasma Cd was either Cd2+, small inorganic Cd complexes or bound to organic molecules with a molecular weight smaller than 1 000. Cadmium was primarily bound to high molecular weight protein(s) (>60 000 daltons) within the plasma. This plasma protein-Cd complex has a low affinity constant (approximately 104
M
-1), indicating non-specific Cd binding, although the capacity for Cd-binding in the plasma is great (as high as 200 g Cd per ml of plasma). Blood plasma may be far more important in metal transport than has previously been realized. 相似文献
12.
Vladimír Bencko Ji?í Rame? Eleonora Fabiánová Ji?í Pe?ek Marián Jakubis 《Environmental geochemistry and health》2009,31(Z1):239-243
The subject of the study was the ecological and human health consequences of environmental pollution from emissions arising
from burning local coal with an arsenic content ranging from 900 to 1,500 g/tonne of dry substance. The first indication of
environmental pollution by arsenic-containing emissions was the mass extinction of honeybee colonies. The neurotoxic and carcinogenic
aspects of arsenic exposure were followed. On using a group diagnostics approach, significant hearing losses were detected
in exposed children in both air and bone conduction audiometry at high frequency range (4,000 and 8,000 Hz, respectively).
Exposure assessment of the local population of the Prievidza district, Central Slovakia, was based on biological monitoring.
The criterion of higher exposure was arsenic content in hair exceeding concentrations of 3 μg/g of hair. In a 7.5-km radius
of the exposed region, live about two-tenths of the district population who were considered as “exposed” and rest of the district
served as the “reference” population. The subject of our analysis was a database of 1,503 non-melanoma skin cancer (NMSC)
cases (756 in men and 747 in women) collected from 1977 to 1996 in the Prievidza district, Central Slovakia (population ~125,000).
The age standardized incidence of NMSC (each confirmed by histological examination) in non-occupational settings ranged from
45.9 to 93.9 in men and from 34.6 to 81.4 in women. Analysis of our data demonstrates a positive correlation between human
cumulative exposure to arsenic and incidence of NMSC. 相似文献
13.
The potential impact of exposure to heavy metals and health problems was evaluated at the Tar Creek Superfund site, Ottawa
County, Oklahoma, USA. Observed versus expected mortality was calculated for selected conditions in the County and exposed
cities. Excess mortality was found for stroke and heart disease when comparing the exposed County to the state but not when
comparing the exposed cities to the nonexposed rest of the County. However, sample sizes in the exposed area were small, population
emigration has been ongoing, and geographic coding of mortality data was incomplete. In an exposed community, 62.5% of children
under the age of 6 years had blood lead levels exceeding 10 μg/dl. The relationships between heavy-metal exposure and children’s
health and chronic disease in adults are suggestive that a more thorough investigation might be warranted. A number of possible
environmental and health studies are suggested, including those focusing on possible central nervous system impacts. Unfortunately,
the exposed population is dispersing. One lesson learned at this site is that health studies need to be conducted as soon
as possible after an environmental problem is identified to both study the impact of the most acute exposures and to maximize
study sample size—including those exposed to higher doses—and minimize the loss of individuals to follow-up. 相似文献
14.
Accumulation of cadmium from contaminated water and sediment by the shrimp Callianassa australiensis
The burrowing marine shrimp Callianassa australiensis (Dana) was collected from an uncontaminated area in Western Port, Victoria, Australia in 1977. The shrimp were exposed to cadmium-contaminated water and sediment for 8 wk. The concentrations ranged from 0.5 to 63 g Cd 1-1 for water and 0.5 to 63 g Cd g-1 for sediment. The shrimp accumulated cadmium from water at a rate commensurate with increases in the concentration of cadmium in water and the duration of the experiment. Although the cadmium concentration in the sediments was 103 times higher than that in water, it hat no effect on cadmium uptake by the shrimp. The concentration factors decreased with increasing concentration of cadmium in water but increased as the duration of exposure increased. The shrimp dry weight decreased with increasing concentration of cadmium in water and duration of exposure. As was the case with cadmium uptake by the shrimp, these two factors acted interactively on the shrimp dry weight, but the third factor, concentration of cadmium in sediment, had no effect. 相似文献
15.
Pollution assessment of the lower basin of Lakes Kainji/Jebba, Nigeria: heavy metal status of the waters, sediments and fishes 总被引:1,自引:0,他引:1
The objective of this investigation was to examine the heavy metal status of the lower basin of Kainji dam (used for hydroelectricity generation), which includes Lakes Kainji/Jebba, Nigeria, and the potential for human exposure to heavy metals from eating fish caught in the lakes. Water, sediments and fish were sampled from the lakes and evaluated for As, Cu, Co, Cr, Fe, Hg, Mn, Ni, Pb, Sb, Ti, V and Zn using the EDXRF technique. Fe and Mn were found to be present at high mean concentrations in the water (13 and 9 μg L-1), sediment (7092 and 376 μg g-1) and fish (11.4 and 4.6 μg g-1) samples. Sb (3.2 μg L-1), Ti (4.1 μg L-1), Cr (2.2 μg L-1), Co (1.2 μg L-1), Cu (1.3 μg L-1) and Pb (1.2 μg L-1) in the water samples and Sb (29 μg g-1), Ti (27 μg g-1), V (27 μg g-1), Cr (27 μg g-1), Co (40 μg g-1), Ni (33 μg g-1), Cu (25 μg g-1), Zn (59 μg g-1) and Pb (19 μg g-1) in the sediment samples were found to be of medium mean concentrations. The other metals were present at trace levels (<1 μg), including As and Hg in the fish and sediment samples. There was an appreciable increase in␣metal concentrations in going from the water to the sediment samples. The probable source of the pollutants is anthropogenic, arising from agricultural activities, corrosion/abrasion of the ferrous steel material and additives in the lubricants and insulation used for auxiliary services on the turbine floor of the dam constructed on the lakes. However, natural geological sourcing from the underlying lake rock cannot be totally ignored, particularly the high levels of Fe and Mn in the sediment samples. The potential risk for human exposure to these metals emanates from the fish caught in the lakes and subsequently consumed, as there are already significant levels of these metals in the two fish species analysed, Tilapia (Oreochromis niloticus) and Chrysicthys (Chrysicthys auratus). 相似文献
16.
Effects of copper and cadmium on growth,swimming and predator avoidance in Eurytemora affinis (Copepoda) 总被引:2,自引:0,他引:2
In this study we demonstrate the sensitivity of swimming behavior and predator-escape responses of nauplii of the estuarine copepod Eurytemora affinis to sublethal doses of Cu and Cd. Behavior was generally altered at metal doses below those affecting growth rates or survival of the copepods. Swimming velocities of Cu-dosed nauplii were different from controls at all concentrations of Cu tested (10–50 g l-1 total Cu) after 24- to 48-h exposure, whereas development rate of nauplii was significantly reduced only after 96 h at 25 g l-1. The 96 h LC50 for Cu was approximately 30 g l-1 Cu. Naupliar swimming velocity was also affected by Cd. Swimming speeds were reduced after 24 h at 130 g l-1, and development was slowed after 48 h at 116 g Cd l-1. The 96-h LC50 was >120 g l-1. Little is known of the adaptive role of specific motile behaviors in the success of larval copepods. We investigated the relationship of swimming speed to predator — prey interactions of the nauplii using both real and simulated predators. Nauplii exposed to Cu for 24 h were observed to be generally hyperactive, a condition which could increase their encounter frequency with predators. Reduced numbers of escape responses of nauplii to a simulated predator, another indication of increased vulnerability to predation, were observed only after 48-h exposure to Cu. Nevertheless, feeding rates of non-dosed larval striped bass on dosed nauplii (24 h at 25 g Cu l-1) were significantly higher than on control nauplii. Feeding rates of larval mysid shrimp, however, were not higher on similarly dosed nauplii; 24 h exposure of nauplii to >30 g Cu l-1 did result in increased predation by mysids.Contribution No. 272 of the US EPA Environmental Research Laboratory, Narragansett, Rhode Island 02882, USA 相似文献
17.
An assessment of exposure to mercury in Changchun city has been undertaken. We estimated Hg exposure to members of the general population based on currently available information and our research. We also studied the Hg concentrations in scalp hair of adults. Adults have an estimated intake of all Hg species via all routes of 6.780 μg day−1 (excluding dental amalgam), which equates to an absorbed dose of 1.718 μg day−1. Fish consumption was the most important exposure route (12% of intake, 43% of absorbed dose). Furthermore, air, cereals and vegetables were important exposure routes, and these exposure were estimated for absorbed dosed at 0.296, 0.209 and 0.318 μg day−1, respectively. The mean Hg concentration in hair was 0.448 μg g−1 (range 0.092–10.463 μg g−1). Hg concentration in the hair of males was 0.422 μg g−1 (0.105–2.665 μg g−1), and was 0.474 μg g−1(0.092–10.463 μg g−1) in the hair of females. Neither place of residence nor age had any significant effect on hair Hg concentrations. 相似文献
18.
In a short-term (162 h) accumulation experiment with mussels Mytilus edulis exposed to 100 ppb Cd and fed algal cells (Phaeodactylum tricornutum) in 1986, it was found that uptake via food played an insignificant role compared to direct uptake from ambient water (19 S). From measurements of the filtration rate and Cd uptake rate, it was estimated that the fraction of Cd taken up per liter of water filtered was about 0.15%. The initial uptake of Cd was linear with time and about three times higher in fed than in starved mussels. From the measured uptake of Cd in starved mussels collected in 1982 and exposed to 10, 100 and 200 ppb in long-term experiments (up to 242 d), it was found that the Cd Accumulation rate was not linear with time, and that the Cd uptake was not directly proportional with the exposure concentration. Values as high as 100 to 1 300 ppm Cd (dry wt of soft parts) were measured. It was found that the Cd elimination rate was not directly proportional with the Cd body burden in long-term exposed mussels, thus indicating that a certain fraction of Cd may have been immobilized to metallothioneins. 相似文献
19.
A. Viarengo M. N. Moore G. Mancinelli A. Mazzucotelli R. K. Pipe S. V. Farrar 《Marine Biology》1987,94(2):251-257
It has been confirmed that metallothioneins play an important role in the accumulation of cadmium (Cd) in the digestive gland cells of mussels (Mytilus galloprovincialis Lam.). The content of Cd in the tissue of mussels exposed for 9 d to the metal (estimated dosage of 180 g Cd mussel-1 d-1) was 66.2 ppm. This value is about the same as the metal content found in the digestive gland of Cd-exposed mussels kept in clean water for a recovery period of 28 d. At the end of the recovery period, however, the Cd bound to thionein had increased by approximately 250%. Our data demonstrate that the stability of lysosomes, a biological parameter adopted as a cellular stress index, is extremely low in mussels exposed to Cd for 9 d, but returns to control values in the digestive gland cells of mussels allowed to recover for 28 d in uncontaminated sea water. At this point most of the Cd present in the cytosol is bound to thionein. These data demonstrate the importance of metallothionein induction in the reduction of the cytotoxic effects exerted by high levels of Cd accumulation. The results of tests designed to clarify the reasons for the long biological half-life of Cd demonstrated that, in the digestive gland of mussels, the lysosomes are not able to eliminate Cd either bound to insoluble thionein polymers or to lipid peroxidation products such as lysosomal lipofuscin, both of which are apparently involved in the elimination of copper. The absence of these two mechanisms of metal sequestration and elimination via excretion of residual bodies (tertiary lysosomes) is in agreement with the persistence of cadmium in the digestive gland of mussels. Finally, the results also demonstrate that simultaneous exposure of mussels to Cd and phenanthrene, an established lysosomal membrane destabilizer, did not significantly alter the accumulation of Cd or the kinetics of the metal in mussels. 相似文献
20.
Mohammad Mahmudur Rahman Gary Owens Ravi Naidu 《Environmental geochemistry and health》2009,31(Z1):179-187
Chronic exposure to arsenic (As) causes significant human health effects, including various cancers and skin disorders. Naturally
elevated concentrations of As have been detected in the groundwater of Bangladesh. Dietary intake and drinking water are the
major routes of As exposure for humans. The objectives of this study were to measure As concentrations in rice grain collected
from households in As-affected villages of Bangladesh where groundwater is used for agricultural irrigation and to estimate
the daily intake of As consumed by the villagers from rice. The median and mean total As contents in 214 rice grain samples
were 131 and 143 μg/kg, respectively, with a range of 2–557 μg/kg (dry weight, dw). Arsenic concentrations in control rice
samples imported from Pakistan and India and on sale in Australian supermarkets were significantly lower (p < 0.001) than in rice from contaminated areas. Daily dietary intake of As from rice was 56.4 μg for adults (males and females)
while the total daily intake of As from rice and from drinking water was 888.4 and 706.4 μg for adult males and adult females,
respectively. From our study, it appears that the villagers are consuming a significant amount of As from rice and drinking
water. The results suggest that the communities in the villages studied are potentially at risk of suffering from arsenic-related
diseases. 相似文献