Metals in Laysan Albatrosses from Midway Atoll

We examined the concentrations of lead, cadmium, selenium, chromium, manganese, arsenic, tin, and mercury in the heart, liver, kidney, salt gland, and feathers of adult (n = 10) and young (n = 15) Laysan albatrosses (Diomedea immutabilis) from Midway Atoll in the north-central Pacific Ocean. Lead poisoning has been reported in some Laysans nesting near buildings on Midway, but other heavy metals have not been examined. We examined tissue distribution of metals by age and gender (adults only). We also examined tissue concentrations in three birds with a droop-wing syndrome characteristic of lead poisoning. We compared metal levels in salt gland (a special excretory organ of marine birds) with those in other tissues. All metals varied significantly across tissues in both adults and chicks, and the relative tissue concentrations were similar in adults and chicks for most metals. Adults had higher levels of most metals in most organs, with significant differences mainly for cadmium (up to 20× higher in kidney and salt gland) and for mercury (17× higher in kidney). However, chicks had significantly higher manganese in liver and arsenic in salt gland. The salt gland had concentrations of most metals (except cadmium, selenium, and mercury) comparable to the kidney levels, which is consistent with it serving as an excretory organ for the cations. Chicks with droop-wings had very elevated levels of lead in their tissue (16.8 ppm in feathers, 14 ppm in liver and kidney), whereas levels of other metals were not significantly different from the apparently normal chicks. Received: 1 April 1999/Accepted: 29 June 1999     

Environmental Exposure and Distribution of Lead in Four Species of Raptors in Southeastern Spain

The purpose of this study was to monitor exposure to lead in four species of raptors in Southeastern Spain (Murcia Region). Samples of liver, kidney, brain, blood, and bone from two species of diurnal raptors (European kestrel (Falco tinnunculus) and European buzzard (Buteo buteo)) and two species of nocturnal raptors (Eagle owl (Bubo bubo) and Little owl (Athene noctua)) were obtained during 1994. Relationships were found between size and age of the birds, the nearness to areas of human activity and lead concentrations in tissues. The lead distribution pattern reveals that the bone is the principle organ for accumulation (0.62–43 mg/Kg, dry weight), followed by the kidney (0.03–0.66 mg/Kg, wet weight), and liver (0.017–0.05 mg/Kg, w.w.), and to lesser extent, the brain (0.013–0.223 mg/Kg, w.w.). This distribution pattern indicates that raptors in Southeastern Spain were exposed to environmental low lead levels continuously over an extended period of time. Correlations between lead in bone and lead in soft tissues were higher in European buzzards (r = 0.87–0.95) and Eagle owl (r = 0.71–0.86) than those found in European kestrels (r = 0.53–0.58) and Little owls (r < 0). However, correlations between lead concentrations in soft tissues and in blood were high (r = 0.85–0.99). Received: 3 April 1996/Revised: 30 July 1996     

Heavy metals in soft tissue of white-tailed eagles found dead or moribund in Germany and Austria from 1993 to 2000

Residues of the potentially toxic metals lead, mercury, and cadmium were analyzed in liver and kidney tissue of 61 free-ranging white-tailed eagles (Haliaeetus albicilla) found dead or moribund in Germany and Austria between 1993 and 2000. Highest values and the widest range were detected for lead in liver and for mercury in kidney tissue. Lead concentrations considered to induce lethal lead poisoning (>5 ppm wet wt) were determined in 28% of liver samples. Lead fragments were detected it the gizzards of two specimens, presumably having died from lead intoxication. Histopathological findings in a recently dead white-tailed eagle indicating acute lead exposure comprise degenerative Purkinje cells in the cerebrellum and inclusion bodies in renal tubular cells. Mercury residues in organs are decreasing compared to former studies in periods when organomercury compounds were used as seed dressing. All cadmium values were low or are at background levels in white-tailed eagles. The present study clearly identities lead as a toxic metal poison in white-tailed eagles in Germany and Austria.     

Intercomparison Studies on Distribution and Coassociations of Heavy Metals in Liver, Kidney, and Muscle of Harbor Porpoise, Phocoena phocoena, from Southern Baltic Sea and Coastal Waters of Denmark and Greenland

The concentrations of selected metals such as Cd, Pb, Cu, Zn, Cr, Ni, Mn, and Fe were determined in liver, kidney, and muscle of harbor porpoise (Phocoena phocoena) from three geographical regions, i.e., the Baltic Sea and Danish and Greenland coastal waters. The concentrations of Cd in liver and kidney increased with age of the specimens analyzed. Significant interspatial variations in both hepatic and renal levels of Cd were also observed. Average hepatic levels of Cd in Baltic, Danish, and Greenland specimens were (age range) 0.05–0.09, 0.12–0.25, and 20.6–51.6 μg g⁻¹ dry weight, respectively. Such values for renal Cd were as follows: 0.55–0.71, 0.14–1.84, and 0.55–94.3 μg g⁻¹ dry weight. In contrast to Cd, concentrations of Cu in the liver and kidney of specimens from Baltic, Danish, and Greenland areas did not indicate such great interspatial variability. The average hepatic values amounted to (age range) 14.1–15.5, 22.1–63.6, and 16.3–25.9 μg g⁻¹ dry weight, and kidney contained on the average 7.83–8.80, 11.7–16.2, and 11.1–15.7 μg Cu g⁻¹ dry weight, respectively. The higher levels of hepatic and renal Cd in Greenland specimens than in Baltic ones could be explained by different food composition in the area studied. Baltic porpoises mainly feed on fish (cod, plaice) containing extremely low levels of muscle Cd, but an important diet component of Greenlandic individuals is squid, characterized by elevated levels of Cd. Received: 22 May 2001/Accepted: 11 November 2001     

Lead Toxicosis and Trace Element Levels in Wild Birds and Mammals at a Firearms Training Facility

In May 1999, lead poisoning was diagnosed in a yellow-rumped warbler (Dendroica coronata) and a gray squirrel (Sciurus carolinensis) found at the Federal Law Enforcement Training Center (FLETC), Glynn County, GA, based on detection of 6.2 and 90.0 ppm wet weight (WW) lead in the liver of the warbler and squirrel, respectively. From October 21–26, 1999, 72 wild animals (37 mammals and 35 birds), comprised of 22 different species, were collected from a 24-ha area surrounding the FLETC outdoor firearms shooting range complex to evaluate exposure to lead and other trace elements. Ten animals were used as controls (five mammals and five birds) and were collected from areas 1.5–3 km outside the shooting range area. Kidney and liver tissues were analyzed for lead, zinc, and other trace elements. Bird gizzards and white-tailed deer abomasums were examined grossly and radiographically to detect metallic objects. Twenty-four (33.3%) animals (11 species) had kidney or liver tissue lead levels > 1.00 ppm, and 12 of these (6 species) had levels > 2.00 ppm. Carcasses of one brown-thrasher (Toxostoma rufum) and two white-tailed deer (Odocoileus virginianus) contained lead fragments. Elevated liver tissue levels of zinc (111.0 ppm) were detected in one brown thrasher that also had elevated kidney and liver tissue lead levels. In February 2000, seven yellow-rumped warblers and one solitary vireo (Vireo solitarius) found dead near the FLETC firearms shooting range also were diagnosed with lead poisoning, with liver and kidney tissue lead levels from 1.77–11.6 and 4.55–17.8 ppm WW, respectively. This frequency of elevated tissue lead levels among the animals examined, in combination with confirmed lead toxicosis in both avian and mammalian species at FLETC, indicates significant lead exposure of local wild bird and mammal communities via bullets and fragments in and on the soil surface of the four outdoor ranges. Most FLETC firearms training is being shifted to new baffled ranges (four walls with semiopen top) with bullet recovery capabilities to preclude future deposition of lead in the environment; existing outdoor ranges will be remediated to remove existing lead. Received: 20 August 2000/Accepted: 22 February 2001     

Elevated Lead Exposure in American Woodcock (Scolopax minor) in Eastern Canada

We investigated the degree and incidence of elevated lead (Pb) accumulation in the American woodcock (Scolopax minor) in eastern Canada by measuring the concentration of Pb in undamaged wing bones of 1,588 birds from Ontario, Quebec, Nova Scotia, and New Brunswick. Overall median bone-Pb concentrations were 21 μg/g (DW) for adults and 11 μg/g for young of the year. A high proportion of birds had elevated Pb concentrations, compared with other wild bird species. Fifty-two percent of adults and 29% of young of the year had bone concentrations exceeding 20 μg/g. Pb concentration varied significantly with age, gender, and geographical region (p ≤ 0.0001). Mean Pb concentrations were lower for young of the year than for adults and lower for males than for females in both age groups. Atlantic Canada (New Brunswick and Nova Scotia) tended to have the highest frequency of individuals with elevated Pb accumulation. Potential sources of Pb exposure in woodcock include ingestion of spent lead shot from hunting, ingestion of Pb-contaminated soil, and/or ingestion of Pb-contaminated earthworms. Received: 14 July 1998/Accepted: 4 November 1998     

Assessing the risk of lead exposure for the conservation of the endangered Pyrenean bearded vulture (Gypaetus barbatus) population

Acute and chronic lead (Pb) poisoning have been recognized as some of the most important causes of mortality for raptors worldwide. We simultaneously examined the recent, medium-term and long-term lead exposure of the endangered bearded vulture (Gypaetus barbatus) from the Pyrenees (northern Spain and southern France). One hundred and one blood samples from 87 captured individuals and tissue samples (liver and bone) from a further 43 dead individuals were analyzed for lead residues. The majority of individuals examined had very low lead concentrations in blood, liver and bone. However, two individuals showed elevated blood Pb levels, two individuals showed liver lead concentrations indicative of excessive lead exposure and one individual showed bone lead levels indicative of chronic lead poisoning, suggesting that the Pyrenean population is not free from the risk of poisoning. We found that Pb exposure was significantly higher in adult individuals as well as in the northern (France) and eastern (Catalonia) range of their distribution. These differences could be related to different feeding habits between age classes (pre-adults are more linked to supplementary feeding sites) and differences in hunting practices between regions (in some regions, carcasses and offal of game animals are not retrieved). Blood, liver and bone lead levels found were slightly higher during the hunting season than outside of the hunting season. Lead presents an unnecessary threat to adult birds and the only way to remove this risk is to ban all hunting with lead within the range of distribution of the endangered bearded vulture. Acute and chronic lead poisoning should be considered in differential diagnosis in any diseased or injured wild bearded vulture, especially subadult and adult individuals, and the potential risk of Pb poisoning should be considered in future reintroduction programs.     

Lead Concentration in the Bones of the Feral Pigeons (Columba livia): Sources of Variation Relating to Body Condition and Death

This paper reports on lead concentrations in the tarsometatarsi of 84 individuals of adult feral pigeons Columba livia found dead or experimentally captured in Bratislava, Slovakia. The interrelationships between lead concentrations and time of death, place of death, body measurements, sex, condition, and plumage phenotype were investigated. Size and shape of pigeons was not correlated with bone lead contamination. Sex and plumage color and pattern were slightly associated with variation in bone lead levels, females and melanic (urban) phenotypes tending to have higher bone lead concentrations than males and blue-bar (wild) individuals. Birds with antibodies to chlamydiae did not contain significantly higher lead concentrations in the tarsometatarsi than birds without antibodies. Concentration of lead in tarsi was significantly higher in birds dying in winter, compared to birds dying at the end of summer. Chronic lead poisoning probably causes mortality in pigeons in winter. The natural stressor, cold weather, has the capability of exacerbating the effects of lead poisoning, and the mortality is due to lead exposure coupled with cold stress. Received: 7 May 1997/Accepted: 3 January 1998     

Toxicity of Lead-Contaminated Sediment to Mute Swans

Most ecotoxicological risk assessments of wildlife emphasize contaminant exposure through ingestion of food and water. However, the role of incidental ingestion of sediment-bound contaminants has not been adequately appreciated in these assessments. This study evaluates the toxicological consequences of contamination of sediments with metals from hard-rock mining and smelting activities. Lead-contaminated sediments collected from the Coeur d'Alene River Basin in Idaho were combined with either a commercial avian maintenance diet or ground rice and fed to captive mute swans (Cygnus olor) for 6 weeks. Experimental treatments consisted of maintenance or rice diets containing 0, 12 (no rice group), or 24% highly contaminated (3,950 μg/g lead) sediment or 24% reference (9.7 μg/g lead) sediment. Although none of the swans died, the group fed a rice diet containing 24% lead-contaminated sediment were the most severely affected, experiencing a 24% decrease in mean body weight, including three birds that became emaciated. All birds in this treatment group had nephrosis; abnormally dark, viscous bile; and significant (p ≤ 0.05) reductions in hematocrit and hemoglobin concentrations compared to their pretreatment levels. This group also had the greatest mean concentrations of lead in blood (3.2 μg/g), brain (2.2 μg/g), and liver (8.5 μg/g). These birds had significant (α = 0.05) increases in mean plasma alanine aminotransferase activity, cholesterol, and uric acid concentrations and decreased plasma triglyceride concentrations compared to all other treatment groups. After 14 days of exposure, mean protoporphyrin concentrations increased substantially, and mean δ-aminolevulinic acid dehydratase activity decreased by more than 95% in all groups fed diets containing highly contaminated sediments. All swans fed diets that contained 24% lead-contaminated sediment had renal acid-fast intranuclear inclusion bodies, which are diagnostic of lead poisoning in waterfowl. Body weight and hematocrit and hemoglobin concentrations in swans on control (no sediment) and reference (uncontaminated) sediment diets remained unchanged. These data provide evidence that mute swans consuming environmentally relevant concentrations of Coeur d'Alene River Basin sediment developed severe sublethal lead poisoning. Furthermore, toxic effects were more pronounced when the birds were fed lead-contaminated sediment combined with rice, which closely resembles the diet of swans in the wild. Received: 12 July 2001/Accepted: 11 October 2002     

Contaminant Exposure and Biomarker Responses in Spectacled Eiders (Somateria fischeri) from St. Lawrence Island, Alaska

Effects of chemical contaminant exposure may be contributing to the decline of spectacled eiders (Somateria fischeri) nesting in coastal areas of western Alaska. We evaluated chemical exposure and potential effects in 20 male eiders collected near St. Lawrence Island, Alaska. Analytes included metals, trace elements, chlorinated organics, and ¹³⁷Cesium (¹³⁷Cs). Effects of contaminant exposure were evaluated using histopathology and biochemical measures of porphyrin profiles, cytochrome P450 activities, and metallothionein (MT) concentrations. Copper, cadmium, and selenium concentrations were elevated in spectacled eiders when compared to literature values for other marine birds. Only a few samples had trace concentrations of chlorinated organic compounds. Muscle ¹³⁷Cs levels were all below the average minimum quantifiable concentration of 0.079 Bq/g. No histopathological lesions were associated with elevated contaminant concentrations in liver, kidney, or testes. Protoporphyrin was found in highest concentration in both the liver and kidneys, followed by coproporphyrin and uroporphyrin, respectively. Hepatic uroporphyrin concentrations correlated significantly to hepatic arsenic concentrations. Mean activities of hepatic EROD, MROD, BROD, and PROD were consistent with other avian species. Comparisons of cadmium/MT ratios from this study to published literature ratios in seven marine avian species suggest that, although adult male spectacled eiders have elevated liver concentrations of certain MT-inducing metals, their MT concentrations are not as strongly induced as would be predicted based on literature values. Despite elevated metal concentrations, the apparent good health of the St. Lawrence Island birds suggests that should these contaminants be a factor in population declines, they likely act by decreasing fecundity or survival of young rather than via direct health impacts on adult male spectacled eiders. Received: 17 March 1999/Accepted: 7 June 1999     

Mercury in Wetland Birds of Iran and Iraq: Contrasting Resident Moorhen, <Emphasis Type="Italic">Gallinula chloropus,</Emphasis> and Migratory Common Teal, <Emphasis Type="Italic">Anas crecca,</Emphasis> Life Strategies

We document mercury distribution in tissues of two waterfowls; moorhen (Gallinula chloropus; n = 6), and Common Teal (Anas crecca; n = 6) from Shadegan wetlands in Southwestern Iran. Mean value of mercury in moorhen liver was (0.36 Hg μg g⁻¹ dry weight), Common Teal had (4.34 Hg μg g⁻¹ dry weight) mercury. In all tissues, Common Teals had significantly higher mercury concentrations than moorhens (U test, p ≤ 0.05). Mercury was 12, 9, 8, and 6 times higher in liver, muscle, kidney, and feather of Common Teals. These birds have comparable diets but Common Teals are migratory and moorhens are residents of Shadegan wetlands.     

Effect of Atrazine on Growth, Photosynthesis, and Between-Strain Variability in Scenedesmus subspicatus (Chlorophyceae)

The magnitude of between-strain differences in the sensitivity of algal species to toxicants is not well known. Yet, informations obtained with a single strain are used for ecotoxicological assessment and for interspecific comparisons. Using 12 strains, we determined whether intraspecific variability occurs in the green alga Scenedesmus subspicatus. We examined growth, photosynthetic activity, and short-term sensitivity thereof to the herbicide atrazine (500 μg · L⁻¹) as well as how these responses are affected by chronic exposure to low atrazine concentrations (0, 1, 5, and 20 μg · L⁻¹). Independent of chronic exposure to atrazine, the strains differed in growth rate and photosynthesis rate. Yet the short-term sensitivity to atrazine was affected by the chronic treatments. All but one strain became more tolerant, their short-term sensitivity being inversely related to the applied atrazine concentration and dependent on the duration of exposure. Differences in response to increments in atrazine concentration resulted in differences in rank order of sensitivity of strains. Moreover, between-strain variability was markedly higher in the atrazine treatments than in the controls. These results can be explained by the significant role of genotype versus environment interactions in determining intraspecific differences in adaptive physiological responses of S. subspicatus to chronic exposure to atrazine. Received: 2 February 1998/Accepted: 26 January 1999     

Mercury Residues in Livers of Bald Eagles (<Emphasis Type="Italic">Haliaeetus leucocephalus</Emphasis>) Found Dead or Dying in British Columbia,Canada (1987–1994)

Postmortem examinations were conducted on 82 bald eagles (Haliaeetus leucocephalus) found dead or dying in British Columbia, Canada, from 1987 to 1994. As part of the examination, livers were analyzed for total mercury (Hg) content, as well as methylmercury (meHg) and selenium (Se) in selected individuals. In total, 67 eagles were classed as having low Hg exposure [total Hg liver residues ranging from 0.5 to 17.2 mg/kg dry weight (dw)]. Fourteen eagles were moderately exposed (liver residues ranging from 19.2 to 36.8 mg/kg Hg dw). One eagle was judged to have died of Hg poisoning, with a total liver Hg content of 130.3 mg/kg dw, of which approximately 77% was meHg. The poisoned eagle and most of the exposed eagles were found in locations where effluent from pulp and paper processing plants is discharged along the British Columbia coast. In total, 6% of eagles examined died as a result of acute metal toxicosis (one from Hg poisoning, four from lead poisoning), in comparison to 72% dying from trauma (electrocution, vehicle/power line collision, eagle attack, trap, gunshot, drowning, and asphyxiation) and 11% from disease. The cause of death was undetermined in the remaining 11% of eagles.     

Dermal absorption of N,N-dimethylacetamide in human volunteers

Objectives: We investigated the potential for the dermal absorption of N,N-dimethylacetamide (DMAC: CAS No. 127-19-5) vapor, the biological half-life of N-methylacetamide (NMAC) in urine as the biological exposure item of DMAC, and the adjustment method for urinary concentrations. Methods: Twelve healthy male volunteers (mean age 25.2 years, range 21–43 years) were exposed to DMAC for 4 h on two occasions at intervals of 96 h or above. Each volunteer sat inside a whole-body-type exposure chamber for the dermal exposure experiment or outside the chamber for the inhalation exposure experiment. The temperature and relative humidity in the chamber were controlled at approximately 26 °C and 40% in order to keep the skin (90% naked) of the volunteers dry. DMAC concentrations were 6.1 ± 1.3 ppm for dermal exposure and 6.1 ± 1.3 ppm for inhalation exposure. Urine samples were collected from 0 h through 36 h and at 48 h and 72 h after the exposure. Extrapolations from exposure concentrations for 4 h to 10 ppm for 8 h were performed. Results: Mean dermal absorption was estimated to be 40.4% of the total DMAC uptake. The biological half-lives of urinary NMAC were 9.0 ± 1.4 h and 5.6 ± 1.3 h via skin and lung, respectively. Mean NMAC in urine just after 5 consecutive workdays (8 h/day) at 10 ppm DMAC exposure was assumed to be 33.7 mg/g · Cr (18.6–70.0 mg/g · Cr). Creatinine-adjusted NMAC concentration in urine for each volunteer within 12 h after the exposure was more closely correlated with the total excretion amount of NMAC up to 36 h than with urinary-volume-adjusted or specific-gravity-adjusted NMAC concentration in both the dermal and inhalation exposure experiments. Conclusions: DMAC vapor was significantly absorbed through the skin. Estimated NMAC values indicate that 20 mg/g · Cr NMAC seems to be appropriate as the biological exposure index. Received: 6 August 1999 / Accepted: 9 September 1999     

Effects of Water Cadmium Concentrations on Bioaccumulation and Various Oxidative Stress Parameters in <Emphasis Type="Italic">Rhamdia quelen</Emphasis>

The effects of sublethal cadmium concentrations on oxidative stress parameters were evaluated in Rhamdia quelen. The fish were exposed to 0.44, 236, and 414 μg l⁻¹ cadmium for 7 and 14 days, followed by the same time periods for recovery. Enzymes, such as catalase (CAT), superoxide dismutase (SOD), and glutathione S-transferase (GST), and indicators of oxidative stress, such as thiobarbituric acid-reactive species (TBARS) and protein carbonyl, were verified in fish tissues. In addition, the accumulation of cadmium was evaluated in these tissues. Our results indicate that CAT and GST levels decreased in gills after exposure periods associated with increased TBARS levels. In hepatic tissue, CAT, GST, TBARS, and protein carbonyl levels increased after 7 days of exposure, whereas SOD activity decreased after exposure for 14 days. In the kidney, TBARS levels decreased after exposure for 7 days and increased after exposure for 14 days. During the recovery periods, some variations persisted in gills, liver, and kidney. Cadmium accumulation was most significant in liver, followed by kidney and gills. These results indicate that cadmium concentrations studied invoke a stress response in silver catfish.     

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.     

Urban air pollution: a representative survey of PM2.5 mass concentrations in six Brazilian cities

In urban areas of Brazil, vehicle emissions are the principal source of fine particulate matter (PM_2.5). The World Health Organization air quality guidelines state that the annual mean concentration of PM_2.5 should be below 10 μg m⁻³. In a collaboration of Brazilian institutions, coordinated by the University of S?o Paulo School of Medicine and conducted from June 2007 to August 2008, PM_2.5 mass was monitored at sites with high traffic volumes in six Brazilian state capitals. We employed gravimetry to determine PM_2.5 mass concentrations, reflectance to quantify black carbon concentrations, X-ray fluorescence to characterize elemental composition, and ion chromatography to determine the composition and concentrations of anions and cations. Mean PM_2.5 concentrations and proportions of black carbon (BC) in the cities of S?o Paulo, Rio de Janeiro, Belo Horizonte, Curitiba, Recife, and Porto Alegre were 28.1 ± 13.6 μg m⁻³ (38% BC), 17.2 ± 11.2 μg m⁻³ (20% BC), 14.7 ± 7.7 μg m⁻³ (31% BC), 14.4 ± 9.5 μg m⁻³ (30% BC), 7.3 ± 3.1 μg m⁻³ (26% BC), and 13.4 ± 9.9 μg m⁻³ (26% BC), respectively. Sulfur and minerals (Al, Si, Ca, and Fe), derived from fuel combustion and soil resuspension, respectively, were the principal elements of the PM_2.5 mass. We discuss the long-term health effects for each metropolitan region in terms of excess mortality risk, which translates to greater health care expenditures. This information could prove useful to decision makers at local environmental agencies.     

Antioxidant responses and bioaccumulation in green-lipped mussels (Perna viridis) under acute tributyltin chloride exposure

Green-lipped mussels (Perna viridis) were exposed to waterborne tributyltin chloride (TBTCl) at different concentrations (0.2, 0.4 and 0.8 μg L⁻¹) for up to 72 h. Accumulated TBTCl in Perna viridis correlated linearly with the exposure concentrations of 0.2 μg L⁻¹(R² = 0.772), 0.4 μg L⁻¹(R² = 0.952), and 0.8 μg L⁻¹(R² = 0.909). The results of superoxide dismutase (SOD), glutathione peroxidase (GPx) and malondialdehyde (MDA) all decreased in gill tissues after 24 h of exposure, but the hepatic SOD and the hepatic GPx showed either little or no effect on exposure of TBTCl solutions. Analysis using the Spearman rank correlation coefficient showed the hepatic GPx activity appeared to have a significant negative correlativity (R_s = −0.42) with the exposed TBTCl concentrations, and the hepatic MDA was significantly negatively correlated (R_s = −0.33) with the tissue TBTCl concentrations. Conversely, a significant positive correlation (R_s = 0.60) was shown between the gill MDA contents and exposure time. This study illustrates oxyradical scavenger GPx best correlated with stress level of pollutants among the various antioxidant parameters.     

Content of Lead and Cadmium in Barred Hogfish, Bodianusscrofa, Island Grouper, Mycteroperca fusca, and Portuguese Dogfish, Centroscymnus coelolepis, from Canary Islands, Spain

Concentration of lead and cadmium has been analyzed in Bodianus scrofa and Mycteroperca fusca captured in the Canary Islands coast. Concentration of Pb ranged from 2.53 to 306.40 and 4.97 to 792.00 μg kg⁻¹ respectively, while that of Cd ranged from 1.75 to 1854.50 and 6.78 to 656.00 μg kg⁻¹. The same metals have been analyzed in muscles, liver and skin of Centroscymnus coelolepis from Canary Islands, with contents of Pb and Cd ranged between 24.18–96.12 μg kg⁻¹ and 32.00–3266.58 μg kg⁻¹ respectively, and in the Azores Archipelago, with concentrations of Pb and Cd ranged as follow: 18.41–38.99 μg kg⁻¹ and 5.23–4179.87 μg kg⁻¹ respectively. Percentage of contribution of both metals to the PTWIs, has also been calculated for both fishes.     

1,2- and 1,4-Cyclohexanediol: major urinary metabolites and biomarkers of exposure to cyclohexane, cyclohexanone, and cyclohexanol in humans

The metabolism and toxicokinetics of cyclohexane (CH) and cyclohexanol (CH-ol), important solvents and chemical intermediates, were studied in volunteers after 8-h periods of inhalation exposure at concentrations of 1010 and 236 mg m⁻³, respectively (occupational exposure limits: CH, 1050 mg m⁻³; CH-ol, 200 mg m⁻³). Of the dose of absorbed parent compounds, the yields of urinary CH-ol and 1,2- and 1,4-cyclohexanediol (CH-diol) were 0.5%, 23.4%, and 11.3%, respectively, after exposure to CH and 1.1%, 19.1%, and 8.4%, respectively, after exposure to CH-ol as determined by a gas chromatography method involving hydrolysis of glucuronide conjugates. The metabolic patterns of CH and CH-ol were very similar to that of cyclohexanone (CH-one) studied in the laboratory previously. For all three compounds, peak excretion of CH-ol occurred at the end of the exposure period, after which it decayed rapidly. Excretion curves of 1,2- and 1,4-CH-diol reached maximal values within 0–6 h postexposure, with subsequent elimination half-lives being 14–18 h. The rate-limiting step in the elimination of CH compounds from the organism is renal clearance of CH-diols. Determination of CH-diols in end-of-shift urine samples is recommended as a useful new method of biomonitoring of CH, CH-ol, and CH-one at the workplace. However, due to accumulation of CH-diols in the body during repeated exposure, quantitative relationships between the exposure and the level of CH-diols have to be adjusted according to the day of sampling during the working week. Received: 10 February 1998 / Accepted: 27 June 1998