Effects of point-source PCB contamination on breeding performance and post-fledging survival in the dipper Cinclus cinclus

Despite widespread information on the incidence and biochemical effects of polychlorinated biphenyls (PCBs) in birds, field studies of effects on population processes are still scarce. This is particularly so in passerines. We therefore assessed breeding performance and post-fledging survival in dippers, Cinclus cinclus, breeding along the Afon Mule, a Welsh river where previous work indicated locally elevated PCB concentrations. We hypothesised that marked toxicological effects, including endocrine disruption, would be detectable as altered clutch-size, hatching success, nest success, brood-size, post-fledging survival or recruitment to the breeding population. Congener-specific analysis of PCBs in failed and deserted dipper eggs during 1990-93 revealed that geometric mean concentrations were four to 20 times higher along the Mule than elsewhere in Wales, UK. PCB signatures also varied highly significantly from other locations, with congeners 138, 153 and 180 dominant at the contaminated site, but 118 or 170 more frequent in eggs elsewhere. Subsequent analysis of surface runoff confirmed a small breaker's yard as a point source. Neither laying dates, clutch-sizes, brood-sizes, nest failure nor hatching failure along the contaminated Mule (n=46 breeding attempts and 218 eggs) differed significantly from dippers along adjacent reference rivers (n=82 breeding attempts and 315 eggs) or Welsh rivers as a whole (n=332 breeding attempts and 1534 eggs). Subsequent recaptures of breeding dippers ringed initially as nestlings were nearly identical between the Mule (7.7% of 182 nestlings), the reference set (7.5% of 323 nestlings) and all other Welsh rivers (7.3% of 2821 nestlings). These data illustrate the value of congener-specific analysis of bird's eggs in indicating local PCB sources. The data show also that PCBs can occur in dipper eggs at total concentrations of 0.49 (geometric mean)-1.29 (upper quartile) microg g(-1) wet mass without effects on breeding performance and survival. These values are below those at which biochemical or reproductive effects on other passerines have been detected, but above current concentrations in any other population of European dippers for which PCB data are available. Population effects by PCBs on European dippers are therefore unlikely. Survivors from locally contaminated sites like that in our study might allow field assessments of second-generation effects on breeding performance in wild birds that have developed under PCB exposure.     

Effects of point-source PCB contamination on breeding performance and post-fledging survival in the dipper Cinclus cinclus

Despite widespread information on the incidence and biochemical effects of polychlorinated biphenyls (PCBs) in birds, field studies of effects on population processes are still scarce. This is particularly so in passerines. We therefore assessed breeding performance and post-fledging survival in dippers, Cinclus cinclus, breeding along the Afon Mule, a Welsh river where previous work indicated locally elevated PCB concentrations. We hypothesised that marked toxicological effects, including endocrine disruption, would be detectable as altered clutch-size, hatching success, nest success, brood-size, post-fledging survival or recruitment to the breeding population. Congener-specific analysis of PCBs in failed and deserted dipper eggs during 1990–93 revealed that geometric mean concentrations were four to 20 times higher along the Mule than elsewhere in Wales, UK. PCB signatures also varied highly significantly from other locations, with congeners 138, 153 and 180 dominant at the contaminated site, but 118 or 170 more frequent in eggs elsewhere. Subsequent analysis of surface runoff confirmed a small breaker's yard as a point source. Neither laying dates, clutch-sizes, brood-sizes, nest failure nor hatching failure along the contaminated Mule (n=46 breeding attempts and 218 eggs) differed significantly from dippers along adjacent reference rivers (n=82 breeding attempts and 315 eggs) or Welsh rivers as a whole (n=332 breeding attempts and 1534 eggs). Subsequent recaptures of breeding dippers ringed initially as nestlings were nearly identical between the Mule (7.7% of 182 nestlings), the reference set (7.5% of 323 nestlings) and all other Welsh rivers (7.3% of 2821 nestlings). These data illustrate the value of congener-specific analysis of bird's eggs in indicating local PCB sources. The data show also that PCBs can occur in dipper eggs at total concentrations of 0.49 (geometric mean)–1.29 (upper quartile) μg g⁻¹ wet mass without effects on breeding performance and survival. These values are below those at which biochemical or reproductive effects on other passerines have been detected, but above current concentrations in any other population of European dippers for which PCB data are available. Population effects by PCBs on European dippers are therefore unlikely. Survivors from locally contaminated sites like that in our study might allow field assessments of second-generation effects on breeding performance in wild birds that have developed under PCB exposure.     

Hatching failure in common terns (Sterna hirundo) in relation to environmental chemicals

The hatching success of two Common Tern colonies, a highly contaminated one at the Elbe estuary (Hullen) and a less contaminated one at the Jade (Augustgroden, southern North Sea coast, Germany), was similar in 1988; 69% at Hullen and 73% at Augustgroden. Most egg loss was due to predators. The number of eggs failing to hatch from unknown causes was 6.3% higher at Hullen than at Augustgroden. Egg-shell thickness and strength were not correlated with the chemicals' concentrations. At Hullen unhatched eggs were compared with randomly collected fresh eggs; the former containing a significantly higher amount (20%) of PCBs (134 microg) than the eggs collected at random (112 microg). Seven out of 45 PCB-congeners were found in significantly higher amounts in the failed eggs, among them the toxic congener PCB 138. The two samples showed no difference in mercury concentration, which was 6.2 mg kg(-1), nor difference in shell strength. Eggs of Common Terns breeding at the Elbe estuary had concentrations of some contaminants reaching levels endangering breeding success.     

Organochlorine contaminant assessment in great blue herons using traditional and nonlethal monitoring techniques

A nonlethal method is discussed for the evaluation of contaminant concentrations in whole eggs. Concentrations of pentachlorobenzene, hexachlorobenzene, DDE, and the PCB congeners, BZ-60, BZ-118, BZ-138, BZ-180, and BZ-170 were quantified in tissue samples from great blue herons (Ardea herodias). All tissues within whole eggs from two colonies were homogenized together and analysed for these chlorinated contaminants. Contents and chorio-allantoic membranes (CAMs) of additional whole eggs were separated and analysed. Contaminant distributions were determined for the CAM and contents of whole eggs from the same colonies. CAM tissues remaining in hatched eggs were also analysed for comparative purposes. Utilizing the distributions derived for contaminants between CAM and egg contents and the chemical concentrations determined in CAMs from hatched eggs, contaminant burdens in whole eggs were calculated. This process produced concentration estimates that described actual, whole egg burdens of chlorinated contaminants within a factor of 2 (1.03-3.7). Contaminant burdens in eggs from the two colonies were also statistically different for DDE and total PCB concentrations.     

Fatal embryo chondral damage associated with fluoroquinolones in eggs of threatened avian scavengers

Stabled livestock reared in housed conditions are often subjected to intensive treatments with veterinary drug, which residues may be present in livestock meat ingested by scavengers, but nothing is known about their presence in eggs of wild birds and their potential detrimental effects on breeding success. We searched for residues of veterinary drugs and other toxicants in infertile and embryonated unhatched eggs of griffon vultures (Gyps fulvus) and red kites (Milvus milvus), two threatened avian scavengers. Quinolones (ciprofloxacin and enrofloxacin) were found in most unhatched eggs of both scavenger species clearly associated with severe alterations in the development of embryo cartilage and bones that could preclude embryo movements and subsequently normal development, pre-hatch position and successful hatching. The detrimental effects on developing eggs of veterinary drugs from livestock operations may help to explain reduced breeding success of avian scavengers.     

Biocides in eggs of aquatic birds. Completion of a food chain enrichment study for DDT,PCB and HG

Eggs (N=224) of seven aquatic bird species of Lake Päijänne, Finland, were analyzed for their contents of HCB, DDE, PCB, mercury (TOTHG) and methyl mercury (METHG as per cent of TOTHG). METHG was 85.5 % which is the same as in fish. Also the levels of TOTHG were of the same order of magnitude in eggs and in fish of Päijänne, but the levels of chlorinated hydrocarbons were much higher in eggs. Differences between species were highly significant but the annual and regional differences were mostly insignificant. The chlorinated hydrocarbons correlated positively with each other and with fat contents but insignificantly with mercury contents. Calculation of total residue amounts in egg, juvenile and adult bird specimens exposed an enrichment of DDT to three, PCB to five and mercury to all seven species.     

Limited effects of heavy metal pollution on foraging and breeding success in the curlew (Numenius arquata)

We examined the effect of heavy metal pollution on the foraging success and breeding performance of the curlew (Numenius arquata) along a documented pollution gradient from a point source, and also by comparing foraging and breeding parameters between the polluted site and two non-polluted areas. Prey biomass and abundance, and foraging success did not vary along the pollution gradient, and were no less at the polluted site than in the non-polluted areas. Furthermore, there was no difference in adult weight during incubation between the polluted and non-polluted areas. There were also no differences in measures of breeding success along the pollution gradient, or between areas, which could be attributed to pollution per se. Egg shells from the polluted area had higher concentrations of heavy metals than in the non-polluted areas, and egg shells close to the pollution source were contaminated more than those further from it. However, there was no difference in calcium concentrations of egg shells or egg-shell thickness between areas. We conclude that in this study there were minimal immediate effects of heavy metal pollution on foraging and breeding success in the curlew.     

Reproductive success and chlorinated hydrocarbon contamination of resident great blue herons (Ardea herodias) from coastal British Columbia,Canada, 1977 to 2000

Over the period 1977-2000, eggs of Pacific great blue heron (Ardea herodias fannini) were collected from 23 colonies along the southern coast of British Columbia, Canada, and analyzed for persistent organochlorine (OC) pesticides and polychlorinated biphenyls (PCBs). Concentrations of OC pesticides in eggs declined sharply in the late 1970s, after which there were minimal changes. The sums of PCB congeners were not reduced appreciably during the 1980s and 1990s, but Aroclor 1260 concentrations suggested a sharp decline in PCB contamination of eggs in the late 1970s, similar to that shown for OC pesticides. Eggs collected along or near the Fraser River delta showed higher levels of most pesticides compared to other monitored colonies. Although the delta lands support a long-standing agricultural economy, the primary factors influencing OC levels in the delta colonies were thought to be driven by estuarine processes. We suggest two possible influencing factors were: 1) a greater rate of bioaccumulation in the estuary due to the deposition of particulates collected over a vast area encompassed by the Fraser River watershed; or 2) a higher rate of biomagnification in the estuary due to species differences at lower trophic levels of the heron food chain. Eggs from urban colonies contained higher levels of PCBs. The congener pattern was not clearly different from that observed in less contaminated eggs from rural and pulp mill-influenced colonies, except that colonies in Vancouver had greater proportions of PCB-66, suggesting a local source of Aroclor 1242. Productivity in the coastal heron colonies was highly variable over the period of study, with 71% of recorded colony-wide reproductive failures occurring in colonies near pulp mills. However, the predominant factors influencing reproductive success were probably disturbance by humans and bald eagles, combined with loss and degradation of nesting habitat, and not sublethal toxicity.     

PBDEs, PCBs, and DDE in eggs and their impacts on aplomado falcons (Falco femoralis) from Chihuahua and Veracruz, Mexico

Eggs from aplomado falcons (Falco femoralis septentrionalis) nesting in Chihuahua and Veracruz, Mexico, were analyzed for organochlorine pesticides, PCBs, and PBDEs. p,p′-DDE was the only organochlorine found in all eggs at concentrations ranging from 0.13 to 7.85 μg/g wet weight. PCBs ranged from 0.04 to 2.80 μg/g wet weight and PBDEs from 62 to 798 ng/g lipid weight. DDE concentrations in eggs were not significantly different among regions; however, PCBs were significantly greater (P = 0.015) in Tinaja Verde, Chihuahua than in the other three regions. Also, PBDEs were significantly higher (P < 0.0001) in eggs from Veracruz than in those from Chihuahua. DDE concentrations in eggs were much lower than those associated with eggshell thinning. PBDEs and PCBs were lower than those reported in raptors from industrialized countries. Overall, contaminant concentrations observed suggest no likely impact on hatching success. The PBDE concentrations are among the first to be reported in raptor species in Mexico.     

污染土壤及地下水修复的PRB技术及展望

PRB技术是一类就地修复污染土壤及地下水的新型技术 ,主要由注入井、浸提井和监测井3部分所组成。污染地区的水文地质学研究 ,是实施该技术的关键 ;化学活性物质的筛选、注入的部位、浓度、速率以及是否均匀分布 ,是该技术是否有效的关键要素。胶态零价铁PRB技术 ,被证明是一项修复由卤代烃、卤代芳烃和有机氯农药以及一些有毒金属 (如铬、硒、铀、砷和锝等 )引起的土壤及地下水污染的有效技术。尽管这些技术存在一定的弊病 ,但与传统的处理方法相比 ,其技术上的优势是十分明显的。可以预料 ,这一技术在我国有良好的应用前景     

Organochlorine and heavy metal contamination in non-viable eggs and its relation to breeding success in a Spanish population of Lesser Kestrels (Falco naumanni)

Residues of organochlorines, polychlorinated biphenyls (PCBs), and heavy metals (mercury, cadmium, lead, copper and zinc) were measured in unhatched eggs of Lesser Kestrels (Falco naumanni) collected in southern Spain in 1988-1991. Although contaminants were detected in all eggs, the amounts were generally below levels known to have negative effects on reproduction. This is consistent with the relatively high hatching rate (about 80%) in the studied population. The nestling mortality was severe, however, apparently due to starvation. It cannot be discounted that pesticides had an indirect effect on the kestrel's breeding success by reducing the populations of prey.     

An eleven-year study of chlorinated hydrocarbon insecticide residues in bovine fat in Illinois, 1972-1982

Bovine fat samples in Illinois were monitored for residues of chlorinated hydrocarbon insecticides from 1972 through 1982. The percentage of fat samples that were contaminated with all chlorinated hydrocarbons decreased during the 11-year study. The percentage of samples contaminated with DDT and its analogs decreased most markedly from 82.4% in 1972 to 2.1% in 1982. The percentage of samples contaminated with aldrin/dieldrin and heptachlor/heptachlor epoxide began to decline in 1980 and continued to decrease through 1982.     

An eleven‐year study of chlorinated hydrocarbon insecticide residues in bovine fat in illinois, 1972–1982

Abstract

Bovine fat samples in Illinois were monitored for residues of chlorinated hydrocarbon insecticides from 1972 through 1982. The percentage of fat samples that were contaminated with all chlorinated hydrocarbons decreased during the 11‐year study. The percentage of samples contaminated with DDT and its analogs decreased most markedly from 82.4% in 1972 to 2.1% in 1982. The percentage of samples contaminated with aldrin/dieldrin and heptachlor/heptachlor epoxide began to decline in 1980 and continued to decrease through 1982.     

Trends in organochlorine and mercury levels in Gannet eggs

Levels of DDE, HEOD, PCBs and mercury were measured in Gannet eggs from several colonies around Britain during 1971-1987. At two colonies (Ailsa Craig and Bass Rock) sampled throughout this period, organochlorine levels declined between the early 1970s and 1983, and then increased again. The trends at other colonies, sampled over shorter periods, were generally consistent with those at Ailsa Craig and Bass Rock. Trends in mercury levels were more variable, and increases were observed at four colonies and declines at two. Some shell-thinning occurred in association with DDE contamination. However, levels of this chemical were too low to affect breeding success in the years concerned. The same was probably true of the other chemicals.     

Etiology of chick edema disease in Herring Gulls in the lower Great Lakes

Severe reproductive failure among fish-feeding birds on the lower Great Lakes was investigated in the early 1970s. Examination of Lake Ontario and Lake Erie Herring Gull chicks at hatching showed signs consistent with chick edema disease and thus with the presence of a chick edema factor. Subsequent microcontaminant analysis of stored eggs revealed the presence of 2,3,7,8-TCDD at concentrations that could account for the poor reproductive success and the signs of chick edema disease.     

Red-throated loons (Gavia stellata) breeding in Alaska,USA, are exposed to PCBs while on their Asian wintering grounds

Red-throated loons (Gavia stellata) breeding in Alaska declined 53% during 1977–1993. We compare concentrations of environmental contaminants in red-throated loons among four nesting areas in Alaska and discuss potential ramifications of exposure on reproductive success and population trends. Eggs from the four areas had similar total polychlorinated biphenyl (PCB) concentrations, but eggs from the Arctic coastal plain had different congener profiles and greater toxic equivalents (TEQs) than eggs from elsewhere. Satellite telemetry data indicate that red-throated loons from the Arctic coastal plain in northern Alaska winter in southeast Asia, while those breeding elsewhere in Alaska winter in North America. Different wintering areas may lead to differential PCB accumulation among red-throated loon populations. For eggs from the Arctic coastal plain, TEQs were great enough to postulate PCB-associated reproductive effects in piscivores. The correlation between migration patterns and PCB profiles suggests that red-throated loons breeding in northern Alaska are exposed to PCBs while on their Asian wintering grounds.     

The occurrence of chlorinated and other organic trace compounds in urban air

The concentrations of 42 chlorinated hydrocarbons (boiling point range from 61 °C to 400 °C) and those of 16 selected volatile hydrocarbons were simultaneously measured in ambient air during the period of one year. The measurements were carried out at 12 sites with different air qualities in the city of Hamburg (FRG). Annual means, medians and peak concentrations are presented. Analyses of the concentration distributions and a comparison with emission data show that traffic is the dominant source of hydrocarbons, whereas chlorinated hydrocarbons are predominantly emitted by industrial sources. This results in a fairly uniform urban pattern of hydrocarbons, but highly variable concentrations of low boiling halogenated compounds.     

Stable isotope fractionation analysis as a tool to monitor biodegradation in contaminated acquifers

The assessment of biodegradation in contaminated aquifers has become an issue of increasing importance in the recent years. To some extent, this can be related to the acceptance of intrinsic bioremediation or monitored natural attenuation as a means to manage contaminated sites. Among the few existing methods to detect biodegradation in the subsurface, stable isotope fractionation analysis (SIFA) is one of the most promising approaches which is pronounced by the drastically increasing number of applications. This review covers the recent laboratory and field studies assessing biodegradation of contaminants via stable isotope analysis. Stable isotope enrichment factors have been found that vary from no fractionation for dioxygenase reactions converting aromatic hydrocarbons over moderate fractionation by monooxygenase reactions (epsilon=-3 per thousand) and some anaerobic studies on microbial degradation of aromatic hydrocarbons (epsilon=-1.7 per thousand) to larger fractionations by anaerobic dehalogenation reactions of chlorinated solvents (epsilon=between -5 per thousand and -30 per thousand). The different isotope enrichment factors can be related to the respective biochemical reactions. Based on that knowledge, we discuss under what circumstances SIFA can be used for a qualitative or even a quantitative assessment of biodegradation in the environment. In a steadily increasing number of cases, it was possible to explain biodegradation processes in the field based on isotope enrichment factors obtained from laboratory experiments with pure cultures and measured isotope values from the field. The review will focus on the aerobic and anaerobic degradation of aromatic hydrocarbons and chlorinated solvents as the major contaminants of groundwater. Advances in the instrumental development for stable isotope analysis are only mentioned if it is important for the understanding of the application.     

Organochlorine contaminants in eggs of the yellow-legged gull (Larus cachinnans michahellis) in the North Eastern Mediterranean: is this gull a suitable biomonitor for the region?

Levels of eight PCB congeners and thirteen organochlorine pesticides were measured in eggs sampled at four yellow-legged gull colonies from the Aegean Sea (NorthEastern Mediterranean) in 1997. There were no significant differences among colony areas in the median concentrations in any of the pollutants whereas cluster analyses did not generally reveal reasonable pollution patterns. The maximum concentrations of four congeners were found at Kinaros colony and of nine compounds were found at Lipsos colony. Fingerprints in both groups were similar in all areas. Of PCBs, congener 28, 118, 138, 180 and of pesticides beta-BHC and 2,4'-DDD were prominently dominant suggesting a particular pollution pattern in this region. Statistically significant correlations were found between most of the higher PCBs in all areas studied. The DDT metabolites correlated mostly with other OCs. We suggest that regional pollution by both groups is not adequately reflected in the eggs of this gull probably due to its extensive scavenging habits and, though information is needed from more colonies, it seems to be a poor biomonitor for organochlorines in this region.     

Chlorinated hydrocarbons and shell thinning in eggs of (Accipiter) hawks in Ontario, 1986-1989

Eggs of sharp-shinned hawks (Accipiter striatus), Cooper's hawks (A. cooperii), and northern goshawks (A. gentilis) were collected from nests in south-central Ontario from 1986 to 1989. Detectable levels of the chlorinated hydrocarbons DDE, DDT, DDD, mirex, photomirex, cis-nonachlor, trans-nonachlor, oxychlordane, dieldrin, heptachlor expoxide, HCB and PCB were present in all the eggs analyzed. Mean contaminant levels were highest in sharp-shinned hawks, slightly lower in Cooper's hawks, and significantly lower in goshawks; for example, mean DDE values were 7.23, 4.48 and 0.90 mg kg(-1) (wet weight), respectively. Total PCB levels were generally less than 1.5 mg kg(-1), lower than those associated with reproductive effects in field and laboratory studies with other species. Mean shell thicknesses of sharp-shinned and Cooper's hawk eggs were significantly less than mean pre-DDT era thicknesses (-10 and -8%, respectively), reductions that were probably not relevant to reproductive success. Goshawk eggs exhibited no significant reduction in shell thickness. Contaminant levels among the three species probably reflect differing food habits and migratory patterns.