Metal Kinetics and Respiration Rates in F1 Generation of Carabid Beetles (Pterostichus oblongopunctatus F.) Originating From Metal-Contaminated and Reference Areas

We investigated resistance to metals in carabid beetles inhabiting metal-polluted and reference areas. Chronic multigeneration exposure to toxic metal concentrations may potentially result in adaptation through decreased metal uptake rate and/or increased excretion rate. The cost of resistance to pollution could be associated with increased metabolic rate. To test these predictions, laboratory cultured F₁-generation beetles originating from metal-polluted and reference sites were exposed to food contaminated with zinc and/or cadmium for 10 weeks. After that, uncontaminated food was offered to the animals for another 3 weeks. During the experiment, internal concentrations of Cd and Zn were measured as were respiration rates of the animals. The results obtained show no significant differences in metal accumulation and excretion patterns or respiration rates between the populations. This may suggest that adaptation has not occurred in the beetles chronically exposed to toxic metal concentrations. The possible explanations for the lack of differences between the populations are discussed.     

Effect of Pollution History on Immunological Responses and Organ Histology in the Marine Mussel Mytilus edulis Exposed to Cadmium

The effect of previous toxicant exposure (i.e., exposure history) on an organism’s response to re-exposure to the toxicant is of considerable interest. The marine mussel Mytilus edulis was collected from reference and polluted sites in southwest England, and groups of mussels from each site were exposed to 20 μg/L CdCl₂ for 0, 1, 4, and 8 days and compared with unexposed controls. End points evaluated were tissue metal and electrolyte concentrations, haemolymph chemistry, haemocyte characteristics [counts, neutral red uptake (NRU), and phagocytosis], histology, and expression of metallothionein gene (mt10) expression in digestive glands. Field-collected animals differed by collection site for some end points at time zero, at which time tissue Fe and Pb concentrations were greater and NRU and condition index lower in mussels from the polluted site. Subsequent exposure to cadmium (Cd) in the laboratory caused Cd accumulation mainly in digestive gland, but there were no site-specific effects on tissue trace-metal concentrations. NRU, phagocytosis, and haemolymph Na⁺ and K⁺ concentrations differed among sites and Cd treatment, but there were no clear trends. Exposure to Cd resulted in lower Ca²⁺ concentrations in gill, digestive gland, and haemolymph in animals from the polluted site compared with controls (Kruskal–Wallis, p ≤ 0.05). Lesions, including necrosis, inflammation, and neoplasia, were observed in animals from the polluted site, but the frequency of these lesions appeared to decrease unexpectedly after Cd exposure. Expression of mt10 increased 3-fold in Cd-exposed animals from the polluted site compared with all other groups (Kruskal–Wallis, p = 0.01). We conclude that Cd exposure affected some immune responses in M. edulis, but pre-exposure history influenced toxicological outcomes of Cd exposure in the laboratory.     

Heavy Metals in the Nase, Chondrostoma nasus (L. 1758), and Its Intestinal Parasite Caryophyllaeus laticeps (Pallas 1781) from Austrian Rivers: Bioindicative Aspects

Tissue samples from 121 adult specimens of the predominantly herbivorous fish species nase, Chondrostoma nasus (L. 1758), from five river sites in Austria were analyzed for their metal content. Sediments and water samples of the sites show different levels of metal load, with only one site considered being polluted with metals. The concentrations of cadmium, copper, lead, and zinc in the tissue of the gills, muscle, intestine, and liver of the fish were determined by inductively coupled plasma–optical emission spectrometry (ICP-OES). As in one of the unpolluted and the polluted river site, a well-established population of the tapeworm Caryophyllaeus laticeps (Pallas, 1781) occurred in the intestine of the fish; pooled samples of this worm were analysed as well. Both the nase and C. laticeps show bioindicative ability for metal pollution in rivers. The results allow a more differentiated characterization of the rivers than the sediment analyses. Cadmium is found mainly in the liver, with maximum concentrations of 1.57 μg/g dry weight from unpolluted sites and 5.58 μg/g from the polluted site. The highest concentrations of copper are also found in the liver, with values between 25 and 333 μg/g. A significantly elevated concentration of Cu in the intestine from an “unpolluted” site (mean: 24.06 μg/g) indicates an acute pollution in this area at the time of sampling. Lead was found mainly in the intestine and liver in concentrations between 0.09 and 4.05 μg/g and 0.26 and 1.94 μg/g, respectively. In the samples from the polluted site, it also could be detected in the gills (mean: 1.38 μg/g). The parasite C. laticeps shows different capacities for metal accumulation: Although the concentrations of Cu were significantly lower compared to the values of the fish liver, cadmium was detected in concentrations up to 5.1 times higher. Lead and zinc concentrations were found to be up to 9.7 and 3.0 times higher in the tapeworm compared to the fish liver, respectively.     

Can Excrement and Feathers of Nestling Songbirds Be Used as Biomonitors for Heavy Metal Pollution?

Although birds have been frequently used as indicators of heavy metal pollution, few studies have examined pollutant levels in nestling passerines. In this paper we determined the levels of two essential (zinc and copper) and three nonessential heavy metals (lead, cadmium, and arsenic) in the excrement and feathers of great (Parus major) and blue tit (Parus caeruleus) nestlings at a polluted site (near a metallurgic factory) and a reference site (4 km farther east). The excrement of both great and blue tit nestlings contained significantly higher concentrations of arsenic, cadmium, copper, and lead at the polluted site. Zinc concentrations did not differ significantly between sites for both species. The feathers of great and blue tit nestlings accumulated significantly higher concentrations of lead at the polluted site than at the reference site. Zinc levels in the feathers of great tit nestlings were significantly higher at the reference site than at the polluted site. For all other elements considered, concentrations did not differ significantly between the two sites. There were no interspecific differences in metal levels between great and blue tits in both excrement and feathers. There was a significant positive correlation between the lead concentration in the excrement and feathers for both great and blue tits. We therefore conclude that excrement of great and blue tit nestlings can be used as a biomonitor for heavy metals (lead, cadmium, arsenic, and copper), whereas feathers appear only to be suitable as a biomonitor for lead pollution. Received: 21 March 2000/Accepted: 9 July 2000     

Inter- and Intraclutch Variability in Heavy Metals in Feathers of Great Tit Nestlings (Parus major) Along a Pollution Gradient

Heavy metal (silver, arsenic, cadmium, copper, mercury, lead, and zinc) concentrations were analyzed in feathers of nestling great tits (Parus major) collected along a pollution gradient. Differences in metal concentrations along the gradient and inter- and intraclutch variability were investigated. In the immediate vicinity of the pollution source, feathers of nestling great tits contained significantly higher concentrations of silver, arsenic, mercury, and lead than at the sites further along the gradient. The concentrations of copper and zinc, two essential metals, were significantly lower at the second most polluted site. There was no significant difference in cadmium concentrations among sites. Most metals, except cadmium, were significantly positively correlated with each other. There was a significant amount of interclutch variability in feather metal concentrations, and they differed significantly among sites. The amount of inter- and intraclutch variability did not differ significantly, although intraclutch variability of most metals was markedly high. Our study indicates that feathers of great tit nestlings could be used as bioindicators of metal pollution, but attention should be paid in designing representative sampling procedures. Received: 2 July 2001/Accepted: 25 March 2002     

Copper, zinc, and cadmium concentrations in Peromyscus maniculatus sampled near an abandoned copper mine

Concentrations of zinc, copper, and cadmium were determined in soil and liver, kidney, bone and stomach contents of deer mice (Peromyscus maniculatus) from two sites near an abandoned mine and one control site, on Vancouver Island, British Columbia, Canada. Soil concentrations of copper were significantly elevated at the mine and off site vs the reference site. In contrast, there was no difference in soil cadmium and zinc concentrations between the mine and reference site. Concentrations of copper, cadmium and zinc in livers of mice from the mine site were significantly elevated relative to the reference and off site locations. Cadmium kidney concentrations tended to be greater in mice from the mine versus the off site and reference site. No differences in bone cadmium, copper and zinc and, kidney copper and zinc concentrations were noted among mice from the three locations. Diet of mice from mine and off sites contained significantly greater copper concentrations than the reference population; no differences in cadmium or zinc diet concentrations in mice from the three sites were noted. Comparison of ratios of metal concentrations in diet:soil and concentrations in liver:soil suggest that for zinc and copper, soil and diet are of equal importance as a source of metal contamination to these mice. In contrast, cadmium diet:soil and cadmium liver:soil ratios were much greater than one indicative of bioconcentration of cadmium from soil to diet and from soil to liver. For assessing routes of metal exposure, in this case for deer mice inhabiting an abandoned mine site, for copper and zinc, soil will most likely be indicative of exposure conditions. In contrast, concentrations of cadmium in diet will be more representative of amounts that the animal is potentially ingesting. Of further importance is that relative to reference sites, mice inhabiting an abandoned copper mine site have significantly elevated tissue levels of copper. This is turn will provide a route of metal exposure to canivorous birds such as owls and hawks. The toxicological significance of this exposure to birds of prey has yet to be assessed adequately.     

Comparison of cadmium kinetics in four soil arthropod species

Soil organisms may play an important role in the transfer of metals through the ecosystem in metal-polluted environments. To evaluate this role, four representative species were compared through modelling their toxico-kinetics when exposed to cadmium in chronic laboratory experiments. Considerable differences in consumption and assimilation of food and cadmium were found between the species. Cadmium assimilation correlated with food assimilation. Cadmium excretion and equilibrium concentrations also differed considerably between the species. The differences in equilibrium concentrations were comparable to the differences between these species in the field. Cadmium assimilation efficiencies were high in the predatorsNotiophilus biguttatus andNeobisium muscorum, and were lower in the saprotrophsOrchesella cincta andPlatynothrus peltifer. Excretion constants were high in the insectsN. biguttatus andO. cincta and low in the arachnidsN. muscorum andP. peltifer. There was no direct relationship between assimilation efficiency and excretion ability. The differences in cadmium assimilation efficiencies reflect differences in trophic level and most probably differences in nutrient demand, which may be determined taxonomically. The influence of excretion ability on the equilibrium concentration is larger than that of assimilation efficiency. Species with a high equilibrium concentration combine low excretion ability with either low or high assimilation. Together with compartment modelling, the study of uptake and excretion of cadmium by individual species provides a suitable tool for predicting the amount in the different soil invertebrates and for calculating pollutant fluxes.     

Copper and zinc levels in serum and urine of cadmium-exposed people with special reference to renal tubular damage

Urinary copper and zinc concentrations and their serum levels were determined in women environmentally exposed to cadmium, including “itai-itai” disease patients and suspected patients, for evaluating the effect of cadmium exposure on metabolism of such essential metals as copper and zinc in human beings. Copper concentrations in the urine of cadmium-exposed women, especially “itai-itai” patients and suspected patients, were much higher than those of nonexposed women. Zinc concentrations in the urine of cadmium-exposed women, however, were not different from those of nonexposed women. Zinc levels in the serum of the “itai-itai” patients were somewhat lower than those of the nonexposed women. On the other hand, serum copper was almost equal in the cadmium-exposed and the nonexposed women. The correlation coefficient between β₂-microglobulin amounts and copper concentrations in the urine of all women examined was as high as 0.95. It is concluded that exposure to cadmium will cause an increase in the excretion of copper in urine, which is attributable to renal tubular damage due to the cadmium exposure, and that urinary zinc excretion is not increased by cadmium exposure, even in the patients who suffer from severe renal tubular damage.     

Accumulation of Lead,Zinc, and Cadmium in a Wild Population of <Emphasis Type="Italic">Clethrionomys glareolus</Emphasis> from an Abandoned Lead Mine

Lead, zinc, and cadmium were determined in a range of tissues from wild populations of bank voles (Clethrionomys glareolus) trapped on an abandoned metalliferous mine site and a reference site. Estimated dietary intakes indicated that animals were exposed to elevated levels of all three metals at the mine site, and this was generally reflected in metal residues in body tissues. Lead concentrations were significantly higher in all tissues of animals from the mine compared to the reference site, while Cd was higher only in the kidney. There was evidence of age-accumulation (using total body weight as an index of age) of Cd in both the liver and kidney of mine site animals but no evidence of such accumulation of lead in bone. In contrast to Cd and Pb, Zn was lower in the tissues of mine site animals compared to the reference site. Based on critical tissue concentrations, the ecotoxicological risk to a wild population of bank voles (Clethrionomys glareolus), associated with total substrate levels of 1 μg g⁻¹ dry weight Cd and 700 μg g⁻¹ dry weight Zn at this mine site is negligible, but that associated with 4000 μg g⁻¹ dry weight Pb may be considered significant. Received: 28 January 2002/Accepted: 29 July 2002     

Diversification of cadmium-binding proteins due to different levels of contamination inArion lusitanicus

Individuals ofArion lusitanicus were collected in the former mining area of Braubach (Federal Republic of Germany) which is highly polluted by various metals. The animals were transferred to the laboratory and fed contaminated litter from their original habitat. Groups of animals from a quarry near Heidelberg were reared in the laboratory and fed diets of different cadmium concentrations. Slugs fed uncontaminated food were used as controls.The concentration of cadmium in the midgut gland of cadmium-fed slugs increased in proportion with the metal concentration of the food. High amounts of zinc and copper were found in the midgut glands of slugs from Braubach. After centrifugation of homogenates, specific patterns of distribution between cytosolic components and pellets were observed for different metals. Cadmium and copper were predominantly bound to cytosolic components, whereas the main portion of zinc was associated with the pellet. In laboratory-fed slugs the increase of cadmium concentration in the food correlated with an increase of the metal content in the homogenate and in two components (supernatant, pellet) of the midgut gland. This correlation was most clearly expressed in the cytosolic components which contained 93–100% of total midgut gland cadmium.Total cadmium in control slugs was associated with components with a molecular weight of more than 15,000. In Braubach and in cadmium-loaded slugs, all the cadmium was bound to a protein with a molecular weight of 10,000, which also contained low amounts of zinc and copper. In highly contaminated individuals fed on the most concentrated cadmium diet, however, a spillover effect was observed, some cadmium being bound to an additional component with a molecular weight of more than 15,000.     

Induced Metal Tolerance in Microbenthic Communities from Three Lowland Rivers with Different Metal Loads

The response of microbenthic communities to sustained metal stress was studied in three lowland rivers with different levels of pollution. Tolerance against zinc and cadmium was determined in short-term toxicity tests with microbenthic assemblages colonizing glass discs. Photosynthetic activity served as an endpoint in tests for algae, whereas for bacteria thymidine incorporation was determined. For bacterial assemblages from unpolluted locations, EC₅₀ values in short-term tests ranged between 6.7 and 56.2 μM zinc, and 8.7 and 25.5 μM cadmium, respectively. Bacterial assemblages from the two most polluted sites were significantly more tolerant for zinc (EC₅₀: 994 μM and >1,000 μM) and cadmium (EC₅₀: 218 μM and 154 μM). Results indicated a shift in community composition toward pollution-adapted organisms when a threshold concentration of 1 μM zinc is exceeded. Although an increasing community tolerance was also indicated for algae, EC₅₀ values for microbenthic algae from all sites exceeded in most cases the highest metal concentrations tested (Zn: 1,000 μM; Cd: 320 μM). Since species composition of algal assemblages was found to change at much lower metal levels, it is concluded that short-term toxicity tests measuring photosynthesis inhibition do not reflect well the long-term effects of these metals. Toxic effects of metals on both algal and bacterial assemblages are attenuated by precipitation and complexing capacities of the biofilm. Received: 9 June 1998/Accepted: 6 December 1998     

Inter- and intraclutch variability in heavy metals in feathers of great tit nestlings ( Parus major) along a pollution gradient

Heavy metal (silver, arsenic, cadmium, copper, mercury, lead, and zinc) concentrations were analyzed in feathers of nestling great tits ( Parus major) collected along a pollution gradient. Differences in metal concentrations along the gradient and inter- and intraclutch variability were investigated. In the immediate vicinity of the pollution source, feathers of nestling great tits contained significantly higher concentrations of silver, arsenic, mercury, and lead than at the sites further along the gradient. The concentrations of copper and zinc, two essential metals, were significantly lower at the second most polluted site. There was no significant difference in cadmium concentrations among sites. Most metals, except cadmium, were significantly positively correlated with each other. There was a significant amount of interclutch variability in feather metal concentrations, and they differed significantly among sites. The amount of inter- and intraclutch variability did not differ significantly, although intraclutch variability of most metals was markedly high. Our study indicates that feathers of great tit nestlings could be used as bioindicators of metal pollution, but attention should be paid in designing representative sampling procedures.     

Accumulation and Soluble Binding of Cadmium, Copper, and Zinc in the Polychaete Hediste diversicolor from Coastal Sites with Different Trace Metal Bioavailabilities

Bioaccumulation of cadmium, copper, and zinc was examined in common ragworms Hediste diversicolor from control (Bay of Somme, Blackwater) and metal-rich (Seine estuary, Boulogne harbor, Restronguet Creek) sites in France and the United Kingdom. The degree of exposure in the field was assessed by considering both total concentrations in superficial sediment and the quantities of metals which may be released in vitro at different pH levels. Among the three contaminated sites, release of the three metals was not detectable in Boulogne harbor, in correlation with limited enhancement of the metal concentrations in the common ragworms from this site. Even at those sites where zinc could be released in vitro from the sediment, zinc concentrations were not enhanced in common ragworms, in agreement with previous findings indicating that the body content of this metal is regulated in H. diversicolor. At all the studied sites, bioaccumulated zinc was mainly in cytosolic form. The distribution of cadmium and copper varied according to the origin of the common ragworms, the insoluble fraction increasing with the degree of contamination (cadmium in the Restronguet Creek, copper in the Seine estuary, and even more in Restronguet Creek). In the cytosolic fraction, metals were partly linked to cytosolic heat-stable thiolic compounds (CHSTC) with molecular masses (5–6 kDa and about 12 kDa) consistent with metallothionein-like proteins (MTLP). Metal-binding to MTLP varied with the degree of contamination and with the metal studied. In contrast to many invertebrates, the presence of metal-binding CHSTC (MM about 2 kDa) other than MTLP seems to be a peculiar feature of H. diversicolor.     

Pollution-Tolerant Allele in Fingernail Clams (Musculium transversum)

For nearly 50 years, the fingernail clam (Musculium transversum) was believed to be virtually eliminated from the Illinois River. In 1991, workers began finding substantial populations of M. transversum in the Illinois River including several beds in and around the highly polluted Chicago Sanitary District. In order to determine if populations of M. transversum from polluted sites exhibited any genetic response to the high levels of toxins and to examine the genetic structure of several populations of M. transversum for any changes due to the population crash, starch-gel electrophoresis was performed on M. transversum from three Illinois River localities and four Mississippi River basin locations. The sampled populations produced an inbreeding coefficient (F_IS) of 0.929, indicating that the populations were highly inbred. The results of a suspected founder effect due to a bottleneck was suggested by an F_ST= 0.442. The isozyme Glucose-6-phosphate isomerase-2 (Gpi-2) produced allelic frequency patterns that were consistent with expected patterns of a pollution-tolerant allele. Polluted sites exhibited elevated frequencies of Gpi-2 ¹⁰⁰ whereas nonpolluted sites exhibited elevated frequencies of Gpi-2 ⁷⁴ . This frequency pattern suggested that natural selection was occurring in populations under severe toxic pressures, leading to an increase in the frequency of the allele Gpi-2 ¹⁰⁰ . Therefore, Gpi-2 ¹⁰⁰ is a possible pollution-tolerant mutation in M. transversum. Received: 29 June 1996/Accepted: 8 February 1998     

Body mass and caloric value of the ground beetle (Pterostichus oblongopunctatus) (Coleoptera, Carabidae) along a gradient of heavy metal pollution

At five sites located along a metal-pollution gradient in southern Poland, we collected, during the spring and summer of 2000, more than 1,200 individuals of the ground beetle (Pterostichus oblongopunctatus) to examine the relationship between pollution level and body mass. Animals from one additional sampling in May 2001 were used to measure body caloric value to verify whether metal pollution has an effect on the energy content of the body. The study sites were located in an area with a history of zinc and lead mining and smelting dating back to medieval times. Metal concentrations in the humus layer ranged from 200 to 9,600 mg/kg of zinc, 120 to 1,600 mg/kg of lead, and 3 to 82 mg/kg of cadmium. We found a significant increase in body mass with increasing pollution level. The beetles from all sites collected near the end of the season were lighter. However, no statistically significant trend in body caloric value was detected. We suggest that the high metal tolerance of the species, combined with altered interspecies competition at the polluted sites, is responsible for the positive correlation between soil metal concentration and body mass.     

Cadmium, zinc, and copper in rabbit kidney metallothionein--relation to kidney toxicity

Twenty-two rabbits were given repeated subcutaneous injection of cadmium chloride. The cumulative cadmium dose given ranged from 13 to 214 mumole/kg body weight. Five rabbits served as controls. The treatment resulted in cadmium concentrations in kidney cortex that ranged from 0.3 to 3.2 mmole Cd/kg and a subsequent production of metallothionein. The molar ratio of cadmium, zinc, and copper in metallothionein fractions from kidneys with different concentrations of cadmium was determined. At low concentrations of cadmium in rabbit kidneys, zinc was the dominating metal bound to metallothionein (70-90%). At high concentrations of cadmium in kidneys, cadmium was the dominating metal in metallothionein. Evidence of kidney toxicity, in the form of beta2-microglobulinuria, was seen when cadmium constituted 85% of the metal ions recovered from metallothionein fractions. The remaining 15% was zinc. This indicates that at most six of the seven metal-binding sites in mammalian metallothionein are occupied by cadmium and that the remaining site is occupied by zinc. Our data provide further support for the hypothesis that chronic cadmium nephrotoxicity develops when there is a lack of metal-binding sites available for cadmium in metallothionein.     

The effects of low environmental cadmium exposure on bone density

Recent epidemiological data indicate that low environmental exposure to cadmium, as shown by cadmium body burden (Cd-U), is associated with renal dysfunction as well as an increased risk of cadmium-induced bone disorders. The present study was designed to assess the effects of low environmental cadmium exposure, at the level sufficient to induce kidney damage, on bone metabolism and mineral density (BMD). The project was conducted in the area contaminated with cadmium, nearby a zinc smelter located in the region of Poland where heavy industry prevails. The study population comprised 170 women (mean age=39.7; 18-70 years) and 100 men (mean age=31.9; 18-76 years). Urinary and blood cadmium and the markers of renal tubular dysfunction (β₂M-U RBP, NAG), glomerular dysfunction (Alb-U and β₂M-S) and bone metabolism markers (BAP-S, CTX-S) as well as forearm BMD, were measured. The results of this study based on simple dose-effect analysis showed the relationship between increasing cadmium concentrations and an increased excretion of renal dysfunction markers and decreasing bone density. However, the results of the multivariate analysis did not indicate the association between exposure to cadmium and decrease in bone density. They showed that the most important factors that have impact on bone density are body weight and age in the female subjects and body weight and calcium excretion in males. Our investigation revealed that the excretion of low molecular weight proteins occurred at a lower level of cadmium exposure than the possible loss of bone mass. It seems that renal tubular markers are the most sensitive and significant indicators of early health effects of cadmium intoxication in the general population. The correlation of urinary cadmium concentration with markers of kidney dysfunction was observed in the absence of significant correlations with bone effects. Our findings did not indicate any effects of environmental cadmium exposure on bone density.     

Fluctuating Life-History Parameters Indicating Temporal Variability in Metal Adaptation in Riverine Chironomids

Adaptation to toxicants in animal populations is influenced primarily by two counteracting forces. First, the intensity and duration of peak concentrations of toxicants is responsible for the actual level of selection pressure on the population. Second, the process of adaptation can be disrupted by gene flow as a result of crossings with nontolerant individuals. These counteracting forces were analyzed in riverine insects in which we expected that the level of metal adaptation is subject of considerable fluctuations, due to variable dilution of metals and a variable transport of nontolerant individuals in river water. To this purpose, the stability of metal adaptation in different Chironomus riparius populations was analyzed during a 5-month period in a heavily polluted lowland river. This was examined by measuring mortality, larval dry weight, and accumulation of zinc under laboratory conditions. The results showed that in midge populations originating from metal-contaminated field sites several life-history parameters (like control mortality and growth response under cadmium exposure) of the laboratory reared F1 generations showed considerable temporal variation. In addition, the presence of metal-adapted midge populations was indicated on several occasions on the metal-exposed field sites. Reference populations on the other hand, showed stable life history patterns throughout the sampling period, and no signs of metal adaptation were found. These observations showed that the actual level of metal adaptation varies considerably, both in time and space. Adaptation to metals in riverine chironomids, therefore, should be looked on as a highly dynamic process. Received: 9 November 1998/Accepted: 14 March 1999     

Environmental exposure to cadmium and renal function of aged women in three areas of Belgium

The relationship between environmental cadmium pollution and prevalence of signs of renal disturbance was investigated. Women over 60 years of age who had spent the major part of their life in a cadmium-polluted area in Belgium (Liège, n = 60) and who had never been occupationally exposed to cadmium constituted the “exposed” group. Women living in two areas less polluted by cadmium (Charleroi, n = 70, and Brussels, n = 45) served as “control” groups. The group of aged women from the Liège area has on the average a higher cadmium body burden, as reflected by an increased excretion of cadmium in urine, than the groups of aged women in the two other areas. The parameters selected for evaluating renal function (urinary excretion rates of total protein, amino acids, β₂-microglobulin, albumin) follow the same trend. Furthermore, a statistically significant correlation was found between the urinary excretion rate of cadmium and that of total protein, amino acids, β₂-microglobulin, and albumin. The results suggest that environmental pollution by cadmium as found in some industrialized areas in Europe may exacerbate the age-related decline of renal function in population groups nonoccupationally exposed to heavy metals.