Organochlorines and eggshell thinning in northern gannets (Sula bassanus) from Eastern Canada, 1968-1984

The northern gannets (Sula bassanus) nesting on Bonaventure Island, Quebec, were studied from 1968 to 1984 in order to measure environmental contaminant levels and their relationship to productivity. Fresh eggs in 1969 contained a mean DDE level of 18.5 mg kg(-1) and had shells which were 17% thinner than pre-1947 samples. Unhatched eggs in 1969 had no outer calcified layer, a mean thickness 20% less than the pre-1947 mean, and mean DDE concentration of 30.6 mg kg(-1). Significantly higher levels of eight contaminants were measured in unhatched than in fresh eggs collected in 1969. DDE and shell thinning were also intercorrelated with nine other contaminants; these data strongly implicate toxic chemicals, particularly DDE, as the main cause for the low breeding success of Bonaventure gannets from 1966 to 1974. Extensive use of DDT to control forest insects around the Gulf of St Lawrence ceased in 1969. Use of DDT, dieldrin and PCBs was restricted in North America during the early 1970s. Residues of DDT, DDD, DDE, PCBs, dieldrin, HCB and chlordane-related compounds in gannet eggs decreased significantly during this study. Heptachlor epoxide remained constant while alpha-HCH appeared to increase. Estimated half-lives ranged from 3.1 years for DDD to 35.4 years for oxychlordane. The breeding success and population of the colony have coincidentally increased.     

Organochlorine contaminants in hair of adolescents from Iassy, Romania

Human hair samples (n=42) from Iassy county (Eastern Romania) collected in 2002-2003 from adolescents were analyzed for hexachlorocyclohexane (HCH) isomers, p,p'-DDT and its metabolites, hexachlorobenzene (HCB), chlordane and metabolites and 5 polychlorinated biphenyl (PCB) congeners. Very low levels were found for HCB and oxychlordane (0.8 and 2.5 ng g(-1)) indicating a low usage of these pesticide formulations in the studied area. In case of HCHs, gamma-HCH isomer was measured at higher median concentrations (79 ng g(-1) hair) compared to the beta-HCH isomer (55 ng g(-1)), which generally is the most prevalent from HCHs. The DDTs profile consisted in p,p'-DDE and p,p'-DDT which levels correspond to 81% of sum DDTs. Very high median concentrations measured for p,p'-DDT (192 ng g(-1)) combined with lower values for p,p'-DDE/p,p'-DDT of 0.4 (from 0.20 to 2.0) in all hair samples suggest recent exposure to "fresh" DDT. When gender was considered, significantly higher concentrations for most of the investigated contaminants were found in girls hair compared to boys. Very high levels were found in the present study for HCHs and DDTs compared to samples from Greece, Western Europe and China. In case of PCBs, the levels found in Romanian samples were found to be in the same range compared to other previously published data.     

Organochlorine contaminants in Caspian and harbour seal blubber

Organochlorine contaminants (pesticides and individual polychlorinated biphenyl congeners, PCBs) were measured in Caspian (Phoca caspica) seal blubber and compared with concentrations in Harbour (Phoca vitulina) seal blubber. Concentrations of total dichlorodiphenyltrichloroethane (DDT) and its metabolites were significantly higher in Caspian seal than Harbour seal samples, whereas PCB congeners were significantly higher in Harbour than Caspian seals. Our finding suggests that Caspian seals are exposed to high levels of DDT pesticides. In contrast, PCBs are circulating in this population at much lower levels than in marine mammals from the North Sea.     

Organochlorine contaminants in narwhal (Monodon monoceros) from the Canadian Arctic

Organochlorine pesticides (DDT, chlordane, polychlorinated camphenes (PCCs), dieldrin, hexachloroheclohexanes (SigmaHCH), mirex), polychlorinated biphenyl congeners (PCBs) and chlorobenzenes (SigmaCBz) were determined in blubber and liver of narwhal (Monodon monoceros) collected during 1982-1983 from Pond Inlet on northern Baffin Island in the Canadian Arctic. PCCs were the predominate organochlorines in narwhal blubber, ranging in concentration from 2990 to 13 200 ng g(-1) (wet wt) in males and from 1910 to 8390 ng g(-1) in females. PCCs consisted of two major components, an octachlorobornane and a nonachlorobornane with gas chromatographic retention times of 1.05 and 1.22, relative to 4,4'-DDE. SigmaPCB concentrations in blubber ranged from 2250 to 7290 ng g(-1) in males and from 894 to 5710 ng g(-1) in females. Seven PCB congeners (tetra-, penta- and hexachlorobiphenyls) accounted for 45% of total PCB (SigmaPCB) in narwhal blubber. Narwhal had 1.4- to 8.6-fold higher ratios of tetra- and pentachlorobiphenyls to PCB-153 (2,2',4,4',5,5'-hexachlorobiphenyl), lower 4,4'-DDE/SigmaDDT ratios and lower proportions of trans-nonachlor to total chlordane components than reported for odontocetes living in more contaminated environments. Mean SigmaPCB concentrations in narwhal were 6- to 15-fold lower than in dolphins from the Canadian east coast and belugas from the St Lawrence River estuary, respectively, while PCC levels were from 4- to about 2-fold lower, and SigmaHCH, dieldrin and SigmaCBz differed by <2-fold. The pattern of organochlorines in narwhal tissues suggests they are exposed to proportionally more volatile compounds, and may have less capacity to metabolize some of these compounds, relative to odontocetes living nearer sources of these contaminants.     

Organochlorine contaminants in Morelet's crocodile (Crocodylus moreletii) eggs from Belize

Non-viable eggs of Morelet's crocodile (Crocodylus moreletii) were collected from Gold Button (GBL) and New River lagoons (NRL) in northern Belize and screened for organochlorine (OC) compounds using gas chromatography (GC) with electron capture detection (ECD). All egg samples from both lagoons (n = 24) tested positive for one or more OCs. Primary contaminants were p,p-DDE and methoxychlor, detected in 100% and 29% of the eggs examined, respectively. Concentrations of individual OC contaminants ranged from 1 ppb (ng chemical/g egg) to > 0.5 ppm (microgram chemical/g egg). Total concentrations of OCs (sum of all OCs) for one egg collected from a nest at GBL reached as high as 0.7 ppm. Sediment samples from both lagoons also tested positive for OCs (lindane, aldrin, methoxychlor, heptachlor epoxide, p,p-DDT, among others). Nest media (soil and plant material) collected from crocodile nests at GBL were positive for p,p-DDT, methoxychlor, aldrin, endosulfan II, and endrin aldehyde. Based on the 24 egg samples analyzed to date, crocodiles from both lagoons are being exposed to OCs. Such exposure may present a health threat to populations of crocodiles in Central America.     

Organochlorine contaminants in seven species of Arctic seabirds from northern Baffin Bay

Organochlorine contaminants (OCs) were determined in liver and fat of seven species of seabirds (Alle alle, Uria lomvia, Cepphus grylle, Rissa tridactyla, Pagophila eburnea, Larus hyperboreus, and Fulmaris glacialis) collected in May/June 1998 from the Northwater Polynya in northern Baffin Bay. OC concentrations ranged over an order of magnitude between seabird species and OC groups, with PCBs having the highest concentrations followed by DDT, chlordane, HCH and ClBz. Positive relationships between delta15N (estimator of trophic level) and OC concentrations (lipid basis) were found for all OC groups, showing that trophic position and biomagnification significantly influence OC concentrations in Arctic seabirds. Concentrations of a number of OCs in particular species (e.g., HCH in P. eburnean) were lower than expected based on delta15N and was attributed to biotransformation. P. eburnea and F. glacialis, which scavenge, and R. tridactyla, which migrate from the south, were consistently above the delta15N-OC regression providing evidence that these variables can elevate OC concentrations. Stable isotope measurements in muscle may not be suitable for identifying past scavenging events by seabirds. OC relative proportions were related to trophic position and phylogeny, showing that OC biotransformation varies between seabird groups. Trophic level, migration, scavenging and biotransformation all play important roles in the OCs found in Arctic seabirds.     

Organochlorine contaminants in the hair of Iranian pregnant women

In the present study, the hair of pregnant women was sampled between November 2007 and January 2008 in Ahvaz and Noushahr cities and the countryside of Noushahr, Iran. They were analyzed for organochlorine pesticides (OCPs), such as dichlorodiphenyltrichloroethane (DDT) and its metabolites, hexachlorobenzene (HCB), α-, β-, and γ-hexachlorocyclohexane (HCH) isomers and seven polychlorinated (PCBs) congeners (IUPAC Nos. 28, 52, 101, 118, 138, 153 and 180). Significant differences between the concentrations of investigated pollutants were found between the locations (p < 0.05). For HCHs, the γ-HCH isomer was measured at higher mean concentrations (6 ng g⁻¹ hair) compared to the β-HCH isomer (0.03 ng g⁻¹), which generally is the most prevalent HCH in biological matrices. Very high mean concentrations of p,p′-DDT in countryside of Noushahr (24 ng g⁻¹) combined with lower values (0.6) of ratio p,p′-DDE/p,p′-DDT in the hair samples suggest recent exposure to “fresh” DDT in this region. Significant differences in OCPs and PCBs were found between primiparous and multiparous mothers (p < 0.05). There was no correlation between levels of OCPs and PCBs in the hair of Iranian pregnant women and their age. There was a significant difference (p < 0.05) in the organochlorine levels, including HCHs, between mothers who have eaten fish once a week and those who consumed fish more than once per week in Noushahr.     

Organochlorine contaminants in cormorant, darter, egret, and ibis eggs from South Africa

During the last 15 years, no research has been published on the levels of pesticides in bird eggs from South Africa, despite the high levels found previously. We analysed eggs from African darter, cattle egret, reed cormorant, African sacred ibis, as well as single eggs from some other species, and found HCB, DDTs, HCHs, chlordanes and PCBs at detectable levels. The presence of mirex in all species was unexpected, since this compound was never registered in South Africa. It also seemed as if terrestrial feeding birds had higher DDE:PCB ratios when compared with aquatic feeding birds. Except for chlordane, the African darter eggs had the highest levels of all other compounds (mean 370 and 300 ng g(-1) ww Sigma pesticides and Sigma PCBs, respectively). Multivariate analysis clearly distinguished the aquatic and terrestrially feeding birds on pollution profile. The African darter (aquatic feeding) and the cattle egret (terrestrial feeding) would be good indicator candidates. Eggshell thinning was detected in the African darter, and was associated with most of the compounds, including DDE and PCBs. We raise a concern that generally longer living birds in warmer climates, laying fewer eggs per clutch, might be at increased risk when compared with trophically similar birds exposed to equivalent levels of pollution in colder climates. Given the scarcity of water and the high biodiversity in Southern Africa, climate change will exert strong pressure, and any additional anthropogenic contamination at levels that can cause subtle behavioural, developmental and reproductive changes, can have serious effects.     

Organochlorine contaminants in eggs of Common Terns from the Canadian Great Lakes, 1981

To determine if contaminant levels in Common Terns had changed over the last decade, we collected and analyzed eggs from four nesting colonies on the three lower Great Lakes during 1981. DDE and PCBs were detected in every egg from the four colonies. Dieldrin, mirex and trans-nonachlor were detected in more than 45% of the eggs. Seven other organochlorine contaminants (DDD, DDT, hexachlorobenzene, oxychlordane, cis-chlordane, cis-nonachlor and toxaphene) were detected in less than 25% of the eggs. Eggs from the Lake Ontario colony were generally the most heavily contaminated. Comparisons of DDE and PCB data with earlier studies of Common Terns indicated that contaminant levels in eggs from the four sampled colonies, or nearby sites, have decreased by up to 80-90% from 1969-1973 to 1981. Interspecies comparisons showed that Common Tern eggs have lower organochlorine residue levels than eggs of Caspian Terns or Herring Gulls. Dietary variation and migratory status are possible explanations for the differences in residue levels among species. Eggshell thickness, log-PCBs, and log-DDE were not significantly intercorrelated. Elevated contaminant levels in the early 1970s might be at least partly responsible for the decline of the Great Lakes Common Tern population over the past decade. Stabilization of population numbers during the early 1980s suggests that organochlorine pollution levels have been reduced to a point where they are no longer an important factor in the population dynamics of this species on the Great Lakes.     

Organochlorine contaminants in albatrosses and petrels during migration in South Atlantic Ocean

Albatrosses and petrels (Procellariiformes) are migratory oceanic birds of considerable conservational interest. Polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were assessed in the subcutaneous fat, liver and muscle of 100 birds belonging to eight species of Procellariiformes collected during their migration period in southern Brazil, one of the most important feeding areas for these species. Although the profiles of PCBs and OCPs were similar among the individuals, with predominance of penta, hexa and heptachlorobiphenyls and p′p-DDE, organochlorine concentrations exhibited a high degree of intra-species variability. The influence of body condition during the migration period in the distribution of organochlorine contaminants was also evaluated, showing that it is a significant factor in the variation and redistribution of these compounds in the tissues of these birds. The intense use of lipid reserves associated to the contamination from organochlorine compounds could be a troubling factor for seabirds with extended breeding periods and that spend most of their lives at sea migrating long distances, such as most of Procellariiformes. Studies on contamination are necessary to improve the knowledge of the threats to these birds and their populations as well as to contribute with information about persistent organic pollutants in the South Atlantic marine environment.     

Organochlorine contaminants in complete clutches of Morelet's crocodile (Crocodylus moreletii) eggs from Belize

Seven complete clutches of Morelet's crocodile (Crocodylus moreletii) eggs were collected in northern Belize and examined for organochlorine (OC) pesticide residues. The primary OC detected, p,p-DDE, was found in every egg analyzed (n=175). Other OCs detected included p,p-DDT, p,p-DDD, methoxychlor, aldrin, and endosulfan I. Concentrations of individual OCs ranged from 4 ppb (ng chemical/g egg wet weight) to greater than 500 ppb. A statistical evaluation of p,p-DDE levels in three complete clutches was used to derive the minimum number of eggs needed from a clutch to precisely determine the mean p,p-DDE concentration representative of that clutch. Sample sizes of 8 (80% confidence level) and 11 (90% confidence level) were determined to yield an accurate estimate of contaminant levels in a full clutch of eggs. The statistically recommended sample size of 11 eggs (at 90% confidence level) was successfully tested on the four additional clutches.     

Organochlorine contaminants in different tissues from Platichthys flesus (Pisces,Pleuronectidea)

Polychlorinated biphenyls (PCBs) and hexachlorobenzene (HCB) are organic contaminants that tend to accumulate in fish. Estuaries are exposed to high anthropogenic activities, therefore tending to accumulate more contaminants than the adjacent coastal waters. Platichthys flesus, a fish with high economic value, was analysed for PCBs and HCB along its different age groups, in liver, gills, gonads and muscle. Younger fishes were caught in the estuary, whereas older fishes were caught in the adjacent coastal waters and acquired at Figueira da Foz Regional Office of Docapesca-Portos e Lotas, SA. Both contaminants concentrations follow the pattern: liver > gills > muscle. Hepatosomatic index had the lowest values in younger fishes and the highest values in older fishes. Condition factor values remain stable with age. Younger fishes had higher PCBs concentrations than the older fishes. In opposition HCB was only detected in fish from 3+ to 5+ and its concentration tended to increase with age. Overall P. flesus is considered safe for human intake.     

Organochlorine contaminants in northeast Atlantic minke whales (Balaenoptera acutorostrata)

Blubber samples of 72 minke whales (Balaenoptera acutorostrata) were obtained from the northeast Atlantic in July and August 1992, and evaluated for organochlorine contamination. The following organochlorines were determined: the industrial chemicals PCBs (polychlorinated biphenyls), and the organochlorine pesticides DDTs (dichlorodiphenyltrichloroethanes), HCHs (hexachlorocyclohexaneb), HCB (hexachlorobenzene) and CHLs (chlordanes). The concentrations of SigmaPCB (sum of concentrations of 18 PCB congeners) and SigmaDDT (sum of concentrations of p,p'-DDT, p,p'-DDE, p,p'-DDD, o,p'-DDT and o,p'-DDD) ranged from 0.6-20.8 and 0.5-14.8 microg g(-1) lipid weight, with mean concentrations at 3.8 and 2.5 microg g(-1) lipid weight, respectively. The mean concentrations of HCB, the chlordane metabolites oxychlordane, cis-chlordane and trans-nonachlor, and the HCH isomers (alpha-, beta- and gamma-HCH) were all < 1 microg g(-1) lipid weight. Significantly higher concentrations of the three major pollutants (SigmaPCB, SigmaDDT and SigmaCHL) were found in mature males as compared to mature females and juveniles of both sexes. No such relationship was found for SigmaHCH and HCB. Stomach contents of northeast Atlantic minke whales indicate considerable heterogeneity in the diet when comparing different years, seasons and geographical areas. However, without knowing more about the minke whale migration pattern, or possible geographical segregation with age and sex, the interchemical variation of organochlorines between sampling areas may not reflect true geographical differences.     

Organochlorine contaminants in the estuarine and coastal marine environments of the Fiji Islands

No information has been published on the presence of organochlorine pesticides and polychlorinated biphenyls in the Fiji Islands. This paper reports the first data on the concentration of a range of organochlorine compounds in sediments and shellfish in the estuarine and coastal marine environment around Fiji. Twenty-three sediment and two shellfish samples were analysed for 22 pesticides and related residues, and PCBs. While a significant number of organochlorines (20 pesticide related species and PCBs) was detected, the concentrations were generally very low (< 10 ng g), indicative of a relatively 'less contaminated' marine environment. Relatively high concentrations were observed only near the two major ports (Suva and Lautoka), with Suva harbour samples having the largest number of detectable species and the largest total concentrations of organochlorines (up to 91 ng g). No PCBs were detected in areas away from major industrial centres. The variations in the concentrations found, and the possible sources and movement of the organochlorine contaminants are discussed.     

Exposure of migrant bald eagles to lead in prairie Canada

The prevalence of elevated exposure to lead was assessed in a migrant population of bald eagles (Haliaeetus leucocephalus) at a waterfowl staging area in the southern portion of the Canadian prairies, from September to November, 1992-1995. Of 103 eagles, 8% exhibited blood lead (PbB) concentrations suggestive of elevated exposure to lead (> or = 0.200 microgram ml-1 wet wt.). PbB concentrations in eagles from the study area ranged from < 0.01 to 0.585 microgram ml-1, while those of nestling eagles from a reference site indicated normal or background exposure (< 0.01 microgram ml-1). No differences in the prevalence of elevated exposure were detected among genders or age classes (0.5- and > or = 1.5-year-old birds) (P > 0.05). The prevalence of elevated exposure was significantly greater in November than in October (21.7 vs. 3.8%) (all years: chi 2Y = 5.75, P = 0.017). Eagles with shotshell pellets in the digestive tract did not have accompanying high PbB concentrations. The prevalence of elevated lead exposure in this study was low in comparison to other areas in North America. Potential biases in the trapping technique as they relate to interpreting the results are addressed.     

Organochlorine contaminants in eggs of seabirds in the Northwest Atlantic, 1968-1984

Eggs of three seabird species, double-crested cormorant (Phalacrocorax auritus). Leach's storm-petrel (Oceanodroma leucorhoa), and Atlantic puffin (Fratercula arctica) were collected at four-year intervals from 1968 to 1984, from colonies in eastern Canada and analyzed for organochlorines. This monitoring study was established to provide data on contamination of the marine environment and possible implications for seabird health. Long-term trend data are presented for PCBs, DDE, dieldrin, HCB, oxychlordane, heptachlor epoxide, HCH and mirex. DDE and PCBs declined significantly in all species from the Bay of Fundy. DDE declined significantly in puffins and petrels while PCBs declined only in petrels from the Atlantic coast of Newfoundland. Generally DDE declined more than PCBs. Dieldrin, oxychlordane, HCH and mirex levels decreased at some locations but were stable at others. Hexachlorobenzene and heptachlor epoxide levels remained steady or increased significantly, depending on the species and location. Organochlorine levels in cormorants from the St. Lawrence River estuary showed no significant trends.     

Bald eagle mortality and chlorinated hydrocarbon contaminants in livers from British Columbia, Canada, 1989-1994

Between 1989 and 1994, we obtained 278 carcasses of bald eagles (Haliaeetus leucocephalus) found dead or dying in British Columbia, Canada. All specimens were necropsied and the cause of death determined wherever possible. Livers from a subset of 75 birds were analyzed for polychlorinated biphenyl (PCB) and organochlorine (OC) pesticide residues. A further subset of 19 eagles found dead around the Strait of Georgia, an area of known pulp mill pollution, in summer, and therefore presumably resident birds, were analyzed for polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) and non-ortho PCBs. Liver concentrations ranged from less than 1 to 190 mg/kg for DDE, and up to 72 mg/kg for total PCBs. Concentrations of other OCs were generally less than 1 mg/kg, with the exception of chlordane-related compounds which were occasionally over 2 mg/kg. All birds analyzed for PCDDs and PCDFs contained detectable concentrations of the major 2,3,7,8-substituted isomers. Some birds were very contaminated; one eagle found near a kraft pulp mill site in 1990 contained: 400 ng/kg 2,3,7,8-TCDD, 1400 ng/kg 1,2,3,7,8-PnCDD and 4400 ng/kg 1,2,3,6,7,8-HxCDD. Birds with higher PCB and dichlorodiphenyldichloroethane (DDE) concentrations appeared to weigh less, and there was a significant negative relationship between both PCBs and DDE and numeric scoring of body condition, reflecting the well known process of starvation-induced mobilization of body lipids and contaminants. Birds with higher 2,3,7,8-TCDD concentrations tended to have unusually low concentrations of 2,3,7,8-TCDF, interpreted to indicate hepatic cytochrome P4501A-type induction by TCDD and subsequent metabolism of TCDF.     

Organochlorine contaminants in coastal marine ecosystems of southern Alaska: inferences from spatial patterns in blue mussels (Mytilus trossulus)

We measured the concentrations and chemical structures of persistent organochlorines (OCs) in blue mussels (Mytilus trossulus) from 44 sites across southwest and southeast Alaska in an effort to determine both the sources of these compounds and the extent to which this region might be contaminated. High PCB concentrations were detected at Amchitka, Adak, and Unalaska Islands (83, 430, and 2800 μg kg⁻¹ dry weight, respectively) in the Aleutians with relatively low concentrations elsewhere (7.1-51 μg kg⁻¹ dry weight). Heavy PCB congener profiles (indicative of localized point sources) characterized the high concentration sites whereas distinctly lighter congener profiles (indicative of atmospheric transport) characterized the lower concentration sites. Elevated PCB concentrations at Adak were restricted to a small area along the island’s eastern shore, suggesting either limited dispersion or rapid dilution of these compounds. More uniform chlorinated pesticide concentrations among the collection sites suggests that these compounds are entering the Aleutian ecosystem from distant sources. Pesticide concentrations correlated significantly with seabird density across the islands we sampled, thus identifying biological transport as a delivery mechanism of these compounds to the Aleutian archipelago. Our findings do not implicate persistent organochlorines as a significant factor in the recent pinniped and sea otter population declines across southwest Alaska.     

Organochlorine contamination in the Great Crested Grebe (Podiceps cristatus): effects on eggshell thickness and egg steroid levels

Eggs of the Great Crested Grebe (Podiceps cristatus) were collected from a breeding area on Lake Maggiore (Northern Italy) from 2001 to 2005 in the vicinity of a p,p'-DDT manufacturer, whose production was stopped in 1996. DDT homologue and PCB congener levels were determined and compared to levels in eggs collected from other breeding areas on Lake Maggiore and in a presumably less contaminated area on Lake Garda. Although Lake Garda eggs on average possessed a lower level of p,p'-DDE than Lake Maggiore eggs, they had significantly higher levels of PCBs and could not be used as a reference population for the measurement of eggshell thickness. Nevertheless, a negative linear relationship was found between p,p'-DDE concentration and eggshell thickness for eggs collected from both lakes, indicating a possible causal relationship. Testosterone and 17beta-estradiol concentrations were also determined for eggs collected from both lakes in 2004. Average concentrations of both hormones were the lowest in eggs from Lake Maggiore; however, the very high variability within broods did not result in any significant difference between the lakes.