Adaptation to soil pollution by cadmium excretion in natural populations of Orchesella cincta (L.) (Collembola)

Population differentiation in Orchesella cincta (L.) (Collembola) populations, from various heavy metal contaminated sites, was studied by comparing cadmium excretion efficiency in first generation (F₁) laboratory individuals. Animals from sites with high metal concentrations in the litter and with a long history of contamination showed significantly higher excretion efficiencies than animals from low pollution, or reference sites. Differences found in the F₁ laboratory animals suggest evidence for genetic differences between the populations.Beneficial and detrimental effects of cadmium excretion were studied in relation to body growth and cadmium concentrations. In chronically exposed animals from an unpolluted site, no physiological acclimation was observed. Excretion efficiency was negatively correlated with body concentrations of cadmium. No detrimental effects were found.Whole-body equilibrium concentrations of cadmium and lead were similar in F₁ animals from the reference site and polluted sites. Significant differences in excretion efficiencies imply that the distribution of toxic metals over body compartments differs, tolerant populations having a higher proportion deposited in the gut. Body concentrations of zinc were consistently higher in animals from the polluted site, during both cadmium and zinc exposure. No detrimental effects of increased cadmium excretion on body concentrations of zinc were observed. Population comparisons of cadmium excretion efficiency data and growth reduction in F₁ laboratory animals showed that both parameters were inversely related. Cadmium and lead contamination were not the sole factors determining tolerance differentiation.     

Impact of an environmentally-realistic intake of cadmium on calcium,magnesium, and phosphate metabolism in bank voles,Clethrionomys glareolus

Oral intake of cadmium can disrupt calcium metabolism in laboratory rodents. If this occurs in free-living wild rodents, reproductive potential, growth, and survival could be adversely affected. This study investigated whether an environmentally-realistic intake of cadmium (1.5–1.7 mg/kg BW/24h) by bank voles, Clethrionomys glareolus, affected uptake and assimilation of calcium and also that of magnesium and phosphorus, two elements metabolized in close association with calcium. Mineral metabolism was monitored in bank voles fed four different diets; two diets were relatively low (0.12%) in calcium and contained either no cadmium (LC) or cadmium (LCCd), while the remainder were relatively high (0.74%) in calcium and also contained either no cadmium (HC) or cadmium (HCCd). Dietary calcium levels were varied because calcium can affect gut absorption of cadmium, and calcium levels in natural forage vary with habitat soil type.Cadmium had a significant effect on voles fed a low calcium diet. Animals given LCCd diet had significantly poorer calcium net gut absorption efficiency than animals fed the corresponding control (LC) diet and were in negative calcium balance, losing approximately 0.5–1% of body calcium reserves each day. In contrast, calcium inputs matched total outputs in animals fed the LC diet. Cadmium had no effect on net gut absorption of magnesium and phosphorus, but renal reabsorption and subsequent assimilation of these elements was greater in animals fed the LCCd diet than in those given the LC diet.Cadmium had no clear effect on macroelement metabolism in bank voles fed a diet relatively high in calcium. Net gut absorption and assimilation of calcium by voles fed the HCCd diet was reduced to the same extent as observed in animals fed the LCCd diet. However, because of their high dietary calcium intake, voles fed the HCCd diet maintained a positive calcium balance and there was no significant difference in calcium assimilation between animals fed the HCCd and HC diet. Cadmium had no effect on magnesium and phosphorus metabolism in voles fed high calcium diets.     

Urinary beta2-microglobulin excretion among people exposed to cadmium in the general environment: an epidemiological study in cooperation between Japan and Sweden.

In a cadmium-exposed area, 138 farming women between 51 and 60 years of age and 40 reference women in the same age group were studied. Cadmium exposure was estimated from data on cadmium concentration in the individual farm's rice production, and on individual residence times. Possible cadmium exposure from the consumption of river water was also taken into account. The average urinary cadmium concentration was about twice as high in the exposed group as in the reference group. Cadmium levels in the blood among the exposed persons were also considerably elevated. Urinary β₂-microglobulin excretion was measured quantitatively as an indicator of renal tubular changes. Increased excretion was strongly related to residence time in the exposed area as well as to the use of contaminated river water in the household. Among the 35 women who had lived only at one place within the exposed area and who had not consumed river water, there was a tendency toward increased β₂-microglobulin excretion with an increased cadmium level in rice and increased residence time. There was also a correlation between cadmium levels in the blood and β₂-microglobulin excretion.     

Heavy Metal Distribution in Some Wild Birds from Korea

This study presents concentrations of heavy metals (manganese, zinc, lead, and cadmium) in tissues in six orders of Korean wild birds (n = 37), 2000–2002. Zinc, manganese, lead, and cadmium concentrations in all tissues were highest in ancient murrelets (Synthliboramphus antiquus). Essential elements in Korean wild birds were within the normal range for wild birds and are maintained there by a normal homeostatic mechanism. Lead concentrations in livers of almost all birds were within the background levels. Cadmium concentrations in livers and kidneys of ancient murrelets exceeded background levels for wild birds, but other birds were within the normal range. Acute and chronic contaminations of lead and cadmium levels differed among groups (or species). We suggest that differences in lead and cadmium concentrations among groups are because of differences in diet and habitat. In ancient murrelets, zinc and manganese concentrations correlated with their cadmium concentration in livers. Zinc, manganese, and cadmium concentrations in murrelet livers were also higher than in other species. Therefore, we suggest that high zinc and manganese concentrations in ancient murrelets were related to their high cadmium concentrations.     

Alterations in life-history traits of Chironomus riparius (diptera) obtained from metal contaminated rivers

Cadmium tolerance in field populations of the midge Chironomus riparius was studied by comparing the effects of chronic cadmium exposure on several life-history parameters using first generation, laboratory-reared animals. Differences between populations of C. riparius were therefore assumed to have a genetic basis. Field populations naturally exposed to metals were less sensitive to cadmium compared to unexposed populations, when larval development time and hatchability of the egg masses were measured. However, larval mortality still increased with cadmium exposure and no differences between exposed and unexposed populations were observed. Furthermore, life-history patterns differed between metal tolerant and nontolerant populations grown under control conditions. Metal tolerant populations were characterized by a high control mortality (50%) or an increased larval development time (with 30%). The results, therefore, indicated the presence of costs of tolerance, while a direct selection on certain life-history characteristics due to metal pollution was absent.     

Cellular mechanisms of cadmium-induced toxicity: a review

Cadmium is a widespread toxic pollutant of occupational and environmental concern because of its diverse toxic effects: extremely protracted biological half-life (approximately 20–30 years in humans), low rate of excretion from the body and storage predominantly in soft tissues (primarily, liver and kidneys). It is an extremely toxic element of continuing concern because environmental levels have risen steadily due to continued worldwide anthropogenic mobilization. Cadmium is absorbed in significant quantities from cigarette smoke, food, water and air contamination and is known to have numerous undesirable effects in both humans and animals. Cadmium has a diversity of toxic effects including nephrotoxicity, carcinogenicity, teratogenicity and endocrine and reproductive toxicities. At the cellular level, cadmium affects cell proliferation, differentiation, apoptosis and other cellular activities. Current evidence suggests that exposure to cadmium induces genomic instability through complex and multifactorial mechanisms. Most important seems to be cadmium interaction with DNA repair mechanism, generation of reactive oxygen species and induction of apoptosis. In this article, we have reviewed recent developments and findings on cadmium toxicology.     

Demographic Responses to Multigeneration Cadmium Exposure in Two Strains of the Freshwater Gastropod, <Emphasis Type="Italic">Biomphalaria glabrata</Emphasis>

A life table response experiment (LTRE) was used to quantify the population-level effects of continuous, multigeneration cadmium exposure on two strains of the freshwater gastropod, Biomphalaria glabrata: the parasite-resistant BS90 and parasite-susceptible NMRI strains. Snails were exposed to waterborne cadmium for three consecutive generations. Survival, growth, and reproduction were measured empirically and incorporated into a stage-based, deterministic population model. Cadmium significantly affected hatching success, time to maturity, and juvenile and adult survival in both strains. There were significant effects of generation on fecundity, hatching success, time to maturity and juvenile survival in NMRI, and time to maturity and adult survival in BS90. Cadmium significantly affected the population growth rate, λ, in BS90. Cadmium, generation, and the cadmium × generation interaction had significant effects on λ in NMRI. At the high cadmium exposure, λ for NMRI showed a decrease from generation 1 to generation 2, followed by an increase from generation 2 to generation 3. The λ value in high-cadmium BS90 steadily decreased over the three generations, while NMRI at this same concentration was similar to the controls. The results indicate that strain-specific differences in response to multigeneration cadmium exposure are evident in B. glabrata. Moreover, effects seen in the first generation are not necessarily indicative of effects in subsequent generations. Changes in λ over the course of the three-generation exposure suggest that acclimation and/or adaptation to cadmium may have occurred, particularly in NMRI at the high cadmium exposure level.     

Cadmium, lead and endometriosis

Objectives: Cadmium (Cd) and lead (Pb) have been demonstrated to exert endocrine disrupting activities. Their possible role in endometriosis, an oestrogen-dependent disease, is unknown. Methods: We compared cadmium urinary excretion (CdU) and blood concentration of cadmium (CdB) and lead (PbB) in 119 patients with peritoneal endometriosis and/or deep endometriotic (adenomyotic) nodules of the rectovaginal septum and 25 controls. Results: The mean levels of cadmium in urine and blood did not differ among the groups. Women suffering from endometriotic diseases showed lower levels of PbB than controls. Conclusions: These data do not support a role for cadmium in the onset or the growth of endometriotic diseases but suggest a possible relationship with lead.     

The effect of lead on mouse brain development.

Biological assimilation and transport of cadmium were determined for an arthropod food chain in an east Tennessee grassland community. Laboratory experiments demonstrated that there were no significant differences (P > 0.05) in assimilation rates (17% assimilation per day) or biological half-lives (7 days) of ¹⁰⁹Cd either as soluble nitrate or insoluble oxide in crickets under identical conditions. Field experiments demonstrated that primary consumers (crickets) accumulated ¹⁰⁹Cd much more rapidly (uptake rate = 0.55 day^?1) than did the spider predators (uptake rate = 0.08 day^?1). Equilibrium concentrations in crickets were obtained in 9 days (0.04 ppm cadmium), while equilibrium was not reached in spiders during the 30-day study. Food-chain concentration of cadmium did not occur as crickets accumulated levels of cadmium 60% of that in their vegetation food sources and spiders accumulated only 70% of the cadmium present in the cricket tissues.     

The Use of Feathers to Monitor Heavy Metal Contamination in Herons, Korea

This study measured concentrations of iron, manganese, zinc, copper, lead, and cadmium in environmental substrates (water and sediment) as well as in the diet and feathers of Black-crowned Night Heron Nycticorax nycticorax and Grey Heron Ardea cinerea chicks from Pyeongtaek heronry, Gyeonggi-do, Korea. Zinc and cadmium concentrations in sediment were relatively high, but lead was low. In the diet, only copper concentrations were higher in Black-crowned Night Herons than in Grey Herons. Cadmium concentrations in the diet of two heron species from a Pyeongtaek heron colony were also higher than reported in other studies. In feathers, iron, copper, and lead concentrations were significantly different between heron species. Iron and copper concentrations were higher in Black-crowned Night Heron chicks than in Grey Heron chicks, but lead concentrations were not. Therefore, with the exception of lead, heavy metal concentrations in feathers were not related to concentrations in the diet. Zinc, iron, and lead concentrations in heron feathers were within the ranges reported by other heron studies, but manganese, copper, and cadmium were much higher. Lead and cadmium concentrations in feathers of Black-crowned Night Heron and Grey Heron chicks were elevated to lead and cadmium concentrations in the diet. Therefore, we suggest that lead and cadmium concentrations in heron feathers reflect contamination of breeding sites and are useful bioindicators of local contamination. An erratum to this article is available at .     

Does subcellular distribution in plants dictate the trophic bioavailability of cadmium to Porcellio dilatatus (Crustacea, Isopoda)?

The present study examined how subcellular partitioning of Cd in plants with different strategies to store and detoxify Cd may affect trophic transfer of Cd to the isopod Porcellio dilatatus. The plant species used were Lactuca sativa, a horticultural metal accumulator species; Thlaspi caerulescens, a herbaceous hyperaccumulator species; and the nonaccumulator, T. arvense. Taking into account that differences in subcellular distribution of Cd in plants might have an important role in the bioavailability of Cd to a consumer, a differential centrifugation technique was adopted to separate plant leaf tissues into four different fractions: cell debris, organelles, heat-denatured proteins, and heat-stable proteins (metallothionein-like proteins). Plants were grown in replicate hydroponic systems and were exposed for 7 d to 100 microM Cd spiked with 109Cd. After a 14-d feeding trial, net assimilation of Cd in isopods following consumption of T. caerulescens and T. arvense leaves reached 16.0 +/- 2.33 and 21.9 +/- 1.94 microg/g animal, respectively. Cadmium assimilation efficiencies were significantly lower in isopods fed T. caerulescens (10.0 +/- 0.92%) than in those fed T. arvense (15.0 +/- 1.03%). In further experiments, Cd assimilation efficiencies were determined among isopods provided with purified subcellular fractions of the three plants. On the basis of our results, Cd bound to heat-stable proteins was the least bioavailable to isopods (14.4-19.6%), while Cd bound to heat-denatured proteins was the most trophically available to isopods (34.4-52.8%). Assimilation efficiencies were comparable in isopods fed purified subcellular fractions from different plants, further indicating the importance of subcellular Cd distribution in the assimilation. These results point to the ecological relevance of the subcellular Cd distribution in plants, which directly influence the trophic transfer of Cd to the animal consumer.     

Removal of Cadmium by <Emphasis Type="Italic">Myriophyllum heterophyllum</Emphasis> Michx. and <Emphasis Type="Italic">Potamogeton crispus</Emphasis> L. and Its Effect on Pigments and Total Phenolic Compounds

In this study, cadmium biosorption by Myriophyllum heterophyllum Michx. and Potamogeton crispus L. was investigated. Although both species were found to be capable of removing cadmium from water, the performance of P. crispus was the most significant. These species were treated with 0, 4, 8, 16, 32, and 64 mg L⁻¹ cadmium solutions for 24, 48, 72, and 96 h, respectively. Cadmium uptake of both species was lowest at 4 mg L⁻¹ and highest at 64 mg L⁻¹. Photosynthetic pigments and total phenolic compounds in both species were determined after exposure to various concentrations of cadmium for various times. Depending on the cadmium accumulation in both species, it was shown to decrease the level of chlorophyll a, chlorophyll b, and carotenoids (24 and 96 h). The anthocyanin concentration in P. crispus increased at all cadmium concentrations studied (0, 4, 8, 16, 32, and 64 mg L⁻¹), whereas in Myriophyllum heterophyllum it increased at the lower cadmium concentrations (0, 4, and 8 mg L⁻¹) but decreased at higher cadmium concentrations (16, 32, and 64 mg L⁻¹), for all exposure periods. The total phenolic compound level in both species increased with cadmium concentration during the 24 and 96 h exposure periods.     

The correlation between blood and urine level of cadmium and nasal and paranasal sinuses disorders

Over exposure to cadmium may produce numerous adverse health effects, including changes in the nasal mucosa. Cadmium levels were measured in blood and urine samples taken from 106 workers who were exposed to high levels of cadmium and nickel in a cadmium nickel battery plant. Pathological results were observed in 46% and 51% of the blood and urine samples respectively. A positive association was found between clinical nasal complaints and pathological levels of cadmium in blood (P=0.006) and urine (P=0.045) samples. All the workers underwent sinus X-rays and 63% of them were abnormal. No correlation was found between pathological sinus X-rays and pathological cadmium level in blood and urine samples. A positive correlation was found between clinical nasal complaints and abnormal sinus X-rays. The prevalence of sinus X-ray abnormalities in an asymptomatic general population is 33% as compared to 63% in our study. This difference is highly significant statistically (P<0.0001). our=" result=" shows=" a=" possible=" harmful=" effect=" of=" cadmium=" on=" the=" paranasal=">     

Urinary excretion of cadmium and zinc among persons from Sweden

Cadmium and zinc concentrations in the urine of 132 Swedes, including 50 pairs of identical twins, were measured. Atomic absorption spectrophotometry procedures were developed for the analysis. Cadmium concentration increased with age and was higher among smokers than among nonsmokers. Estimated 24-hr excretion of cadmium among nonsmokers increased from about 0.25 to 0.40 μg in persons from 20 to 70 years old. The 24-hr cadmium excretions among nonsmokers in different age-groups fitted better to total kidney burden than to daily cadmium intake from food. Zinc excretion, on the other hand, decreased after the age of 20.     

Use of raptors for biomonitoring of heavy metals: gender, age and tissue selection

The concentrations of cadmium, mercury and lead were determined in liver, kidney and feathers of Accipiter gentilis, Buteo buteo and Strix aluco. No significant differences in the concentrations of metals were observed in relation to either age or gender. Cadmium levels in feathers and in kidney were significantly correlated (p < 0.01 or p < 0.05) in all species. In B. buteo, cadmium concentrations in feathers and in liver were also correlated (p < 0.01), as were the concentrations of lead in feathers and in liver (p < 0.05). The low correlation coefficients let to reject the possibility of predicting metals concentrations in viscera from the concentrations in feathers.     

Hexamitiasis in Cadmium-Exposed Mice

? Mortality was observed in 4- to 5-week-old Swiss Webster mice exposed to 300 or 3 ppm cadmium as cadmium chloride in the drinking water.

Mice receiving 300 ppm cadium suffered 26% mortality as compared with 7% of those on the low cadmium dose. Death did not occur in control mice. Clinical signs and histopathology established Hexamita muris as the causative agent. Cadmium lesions were not observed.

It is suggested that mortality due to hexamitiasis resulted from synergism between cadmium and H muris.     

Temporal and spatial variation in the amount of cadmium in the phantom midge larvae (Chaoborus spp.)

Several factors, including body size, age, and temporal and spatial variation, which may influence the amount of cadmium (Cd) in the phantom midge larvae, Chaoborus spp., were examined in eight lakes, four from south-central Ontario (Dorset Region) and four from northwestern Ontario (Experimental Lakes Area). All three species of Chaoborus (C. punctipennis, C. trivittatus, C. flavicans) found in Chub Lake (south-central Ontario), were analyzed seasonally. One species, C. punctipennis, was collected and analyzed from all lakes.Smaller Chaoborus tended to have higher Cd concentrations (g Cd/g dry weight), and lower Cd burdens (ng Cd/Animal) than larger Chaoborus. The Cd concentrations of Chaoborus in Chub Lake were lowest during the summer, which coincided with the fastest growth of the organisms. The Cd burdens differed between species, which was attributed to differences in their asynchronous life histories.Cadmium burdens and concentrations were significantly lower in the organisms from northwestern Ontario than those from south-central Ontario. Lower atmospheric deposition rates, lower Cd concentrations in the lake water, as well as life history differences, may explain these results.     

Comparative Experimental Study of Cadmium and Methylmercury Trophic Transfers Between the Asiatic Clam Corbicula fluminea and the Crayfish Astacus astacus

Cadmium (Cd) and methylmercury (MeHg) trophic transfers were analyzed between the Asiatic clam Corbicula fluminea and the crayfish Astacus astacus. Metal bioaccumulation in crayfish was quantified after 5, 10, and 15 days of exposure via daily ingestion of soft bodies of C. fluminea, previously exposed during 7 days to Cd (20 μg · L⁻¹) and MeHg (4 μg · L⁻¹). Bioaccumulation kinetics in the predator were investigated at organ and tissue levels: hemolymph, tail muscle, hepatopancreas, gills, stomach/mesenteron, intestine, green gland, carapace. Trophic transfer rates were estimated at the whole organism level. Results showed marked differences (1) in assimilation efficiencies, mean transfer rates being 5% for Cd and 16% for MeHg; and (2) in the metal distribution within the different tissue compartments of the crayfish: for Cd, the trophic uptake leads to high concentrations in the hepatopancreas and small accumulation in the muscle tissue; for MeHg, the highest levels of bioaccumulation occur in the green gland and in the tail muscle. From an ecotoxicological point of view, these experimental data suggest a small risk of Cd transfer between the crayfish and predators, humans included; on the other hand, Hg distribution in the muscle and accumulation trends in this tissue represent an obvious risk of transfer. Received: 7 April 1999/Accepted: 9 September 1999     

Effects of cadmium<Emphasis Type="Italic">in vitro</Emphasis> on contractile and relaxant responses of isolated rat aortas

Objective Cadmium is known to affect the vascular tone of isolated blood vesselsin vitro and the arterial pressure of ratsin vivo. However, the mechanisms of cadmium actions on the vascular system have not been clarified. To elucidate the actions of cadmium on vascular tonus, effects of cadmium on vasocontractile and vasorelaxant responsesin vitro were investigated using aortic strips isolated from rats. Methods Aortic strips isolated from male Wistar rats were incubated with CdCl₂ (10μM) for 24 hr, washed with fresh CdCl₂-free medium, and then used for measurement of isometric tension and Western blot analysis of eNOS (endothelial nitric oxide synthase) and iNOS (inducible nitric oxide synthase). Results In the aortas pretreated with cadmiumin vitro, the contractile response to phenylephrine was significantly higher than that in the control aortic strips pretreated with a vehicle. The sodium nitroprusside-induced relaxing response was significantly higher in the aortic strips pretreated with cadmium for 24 hr, compared with that in the control pretreated with a vehicle. The isoproterenol-induced relaxing response was also significantly higher in the cadmium-accumulated aortic strips.In vitro cadmium treatment slightly but not significantly increased the acetylcholine-induced relaxation of the aortic strips. Cadmium treatment induced expression of iNOS and significantly increased expression of eNOS in the aortic strips, while it did not affect expression of β-actin. Conclusions Cadmium treatmentin vitro augmented the α1 adrenoceptor-mediated contractile response, even though eNOS and iNOS were upregulated by cadmium treatment. NO-induced and β-adrenoceptor-mediated relaxing responses were also augmented by cadmium treatment. These results suggest that both vasocontractile and vasorelaxing responses are augmented in cadmium-accumulated aortas.     

环境镉接触人群尿金属硫蛋白排泄与镉致骨损伤效应

目的研究环境镉接触人群尿金属硫蛋白(UMT)的排泄与镉致骨损伤效应的关系。方法镉污染区居民为环境镉接触人群,非污染区居民为对照人群。人群尿镉(UCd)与血镉(BCd)用原子吸收分光光度法测定,用环境接触量估测总镉摄入量(TCd)。UMT、尿β2微球蛋白(UB2M)、尿视黄醇结合蛋白(URBP)及尿白蛋白(UALB)用ELISA法测定,尿N-乙酰-β-D-氨基葡萄糖苷酶(UNAG)和UNAG同工酶B(UNAGB)用荧光分析法测定,均用尿肌酐校正。单光子骨密度仪测定人群前臂骨密度。结果UMT能反映机体接触镉时镉负荷的变化。而高剂量接触镉可先后导致肾功能障碍及骨质疏松。人群UMT排泄量与骨密度的关系同UMT排泄量本身是否异常有关。根据各指标与尿镉的剂量-反应曲线计算得到的基准剂量95%低限水平BMDL值,从小到大排列为UNAGB、UNAG、UB2M、UMT、URBP、T评分及UALB。结论镉致骨质疏松的发生与镉致肾功能障碍有关并迟于后者。UMT不仅能特异而敏感的反映镉致肾的毒性,而且能在一定程度上反映镉对骨骼的损伤。