Accumulation of environmental contaminants in wood duck (Aix sponsa) eggs, with emphasis on polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans

Residues of plant protection products in grey partridge eggs in French cereal ecosystems

The contamination of the eggs of farmland birds by currently used plant protection products (PPPs) is poorly documented despite a potential to adversely impact their breeding performance. In this context, 139 eggs of 52 grey partridge Perdix perdix clutches, collected on 12 intensively cultivated farmlands in France in 2010-2011, were analysed. Given the great diversity of PPPs applied on agricultural fields, we used exploratory GC/MS-MS and LC/MS-MS screenings measuring ca. 500 compounds. The limit of quantification was 0.01 mg/kg, a statutory reference. A total of 15 different compounds were detected in 24 clutches. Nine of them have been used by farmers to protect crops against fungi (difenoconazole, tebuconazole, cyproconazole, fenpropidin and prochloraz), insects (lambda-cyhalothrin and thiamethoxam/clothianidin) and weeds (bromoxynil and diflufenican). Some old PPPs were also detected (fipronil(+sulfone), HCH(α,β,δ isomers), diphenylamine, heptachlor(+epoxyde), DDT(Σisomers)), as well as PCBs(153, 180). Concentrations ranged between <0.01 and 0.05 mg/kg but reached 0.067 (thiamethoxam/clothianidin), 0.11 (heptachlor + epoxyde) and 0.34 (fenpropidin) mg/kg in some cases. These results testify an actual exposure of females and/or their eggs to PPPs in operational conditions, as well as to organochlorine pollutants or their residues, banned in France since several years if not several decades, that persistently contaminate the environment.Routes of exposure, probability to detect a contamination in the eggs, and effects on egg/embryo characteristics are discussed with regard to the scientific literature.

Immunological and reproductive health assessment in herring gulls and black-crowned night herons in the Hudson-Raritan Estuary

Previous studies have shown inexplicable declines in breeding waterbirds within western New York/New Jersey Harbor between 1996 and 2002 and elevated polychlorinated dibenzo-p-dioxins and polychlorinated biphenyls (PCBs) in double-crested cormorant (Phalacrocorax auritus) eggs. The present study assessed associations between immune function, prefledgling survival, and selected organochlorine compounds and metals in herring gulls (Larus argentatus) and black-crowned night herons (Nycticorax nycticorax) in lower New York Harbor during 2003. In pipping gull embryos, lymphoid cells were counted in the thymus and bursa of Fabricius (sites of T and B lymphocyte maturation, respectively). The phytohemagglutinin (PHA) skin response assessed T cell function in gull and heron chicks. Lymphocyte proliferation was measured in vitro in adult and prefledgling gulls. Reference data came from the Great Lakes and Bay of Fundy. Survival of prefledgling gulls was poor, with only 0.68 and 0.5 chicks per nest surviving to three and four weeks after hatch, respectively. Developing lymphoid cells were reduced 51% in the thymus and 42% in the bursa of gull embryos from New York Harbor. In vitro lymphocyte assays demonstrated reduced spontaneous proliferation, reduced T cell mitogen-induced proliferation, and increased B cell mitogen-induced proliferation in gull chicks from New York Harbor. The PHA skin response was suppressed 70 to 80% in gull and heron chicks. Strong negative correlations (r = -0.95 to -0.98) between the PHA response and dioxins and PCBs in gull livers was strong evidence suggesting that these chemicals contribute significantly to immunosuppression in New York Harbor waterbirds.

Standardization of egg collection from aquatic birds for biomonitoring--a critical review

Collecting bird eggs is an established method of biomonitoring for specific pollution hazards. One of the most critical problems with this method is the extreme biological variability in bird eggs, but standardizing the collection and preservation of eggs can reduce these problems. Furthermore, standard practices are required so that the results can be compared among studies because mistakes cannot be corrected by laboratory analysis. Therefore, a standard procedure for collecting and preserving bird eggs may be necessary. The objective of this review is to investigate the current standard of quality assurance in the field by analyzing 86 peer-reviewed papers describing egg collection and use for aquatic birds. We show that little attention has been paid to standardizing how eggs are collected and stored in the field. Important information is often absent, including crucial aspects of sample collection and preservation, such as the freshness of the eggs, the position of the eggs in the laying sequence, the selection criteria, random sampling, and the duration and temperature of transport. Potential standards are suggested and discussed as a foundation for the development of quality assurance standards in the field.

Relationship of PCDD/F concentrations in duck-egg farmers and consumption of ranched duck eggs in central Taiwan

The 2004 food market-basket survey in Taiwan found high levels of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in duck eggs. A subsequent survey in Chang-Hua County, central Taiwan, found nine duck farms for egg production and duck eggs that were highly contaminated by PCDD/Fs in the secondary sampling and analysis during the years 2004 to 2005. Duck-egg farmers eat duck eggs rather than chicken eggs, and the aim of the current study was to evaluate how eating contaminated duck eggs affected serum PCDD/F accumulation and PCDD/F profiles in family members of duck-egg farmers. Forty-two family members of duck-egg farmers and 88 residents living nearby (control group) were recruited. Serum PCDD/F levels were significantly higher in duck-egg farmers than in the control group (28.1 vs 18.6 pg World Health Organization toxic equivalency [TEQ]/g lipid, WHO-TEQ). Significant differences in PCDD/F levels were found for most congeners, especially for 2,3,4,7,8-penta-chlorinated dibenzofurans. Elevated serum PCDD/F levels were positively associated with an increase in monthly duck-egg consumption after adjustments for fish consumption. The current result contradicted results of our previous study, which showed a positive association between fish intake and serum PCDD/F levels. The matter of cultivation in the contaminant area in Chang-Hua County should be considered more seriously.

Organochlorine and PBDE concentrations in relation to cytochrome P450 activity in livers of Forster's terns (Sterna forsteri) and Caspian terns (Hydroprogne caspia), in San Francisco Bay, California

We measured halogenated organic contaminants (HOCs) [polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), and dichloro-diphenyl-trichloroethane (DDT)] and P450 [e.g., ethoxyresorufin-O-dealkylase (EROD)] stress in livers from Caspian tern (Hydroprogne caspia) adults and Forster's tern (Sterna forsteri) adults and chicks in San Francisco Bay (SFB). Penta BDEs and tetra PBDEs composed 46-66% of SigmaPBDE in terns. PCB homologues di, tri, penta, hexa, and hepta composed 93-95% of SigmaPCBs and p'p-DDE composed 82-98% of all SigmaDDTs. We found similar concentrations of SigmaPBDEs [mean micrograms per gram wet weight (ww) +/- standard error = 0.4 +/- 0.1], SigmaPCBs (5.9 +/- 1.6), and SigmaDDTs (0.6 +/- 0.1) among species, sexes, and regions. However, concentrations were higher in Forster's tern adults than chicks (SigmaPBDEs = 0.4 +/- 0.1 and 0.1 +/- 0.1; SigmaPCBs = 7.08 +/- 2.4 and 2.4 +/- 1.4; SigmaDDTs = 0.5 +/- 0.1 and 0.1 +/- 0.1; respectively), and there was a nonsignificant trend of elevated SigmaPBDEs and SigmaPCBs for adult Forster's terns in the Central South Bay and Lower South Bay portions of SFB. Combined Forster's tern and Caspian tern SigmaDDTs bioaccumulated similarly to selenium, but not mercury, and there was a nonsignificant but positive trend for SigmaPBDEs and SigmaPCBs bioaccumulation with mercury. P450 protein activity was higher in adult Forster's terns than Caspian terns, higher in Central South Bay than in Lower South Bay, and higher in adult Forster's terns than in chicks.

Embryo toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin to the wood duck (Aix sponsa)

We examined the sensitivity of the wood duck (Aix sponsa) embryo to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) by injecting the toxicant into their eggs. Six groups of wood duck eggs (n = 35 to 211 per trial) were injected with 0 to 4600 pg TCDD/g egg between 2003 and 2005. Injections were made into yolk prior to incubation, and eggs were subsequently incubated and assessed weekly for mortality. Significant TCDD-induced mortality was not observed through day 25 (90% of incubation). Liver, heart, eye, and brain histology were generally unremarkable. Hepatic ethoxyresorufin-O-deethylase activity, a biomarker of dioxin-like compound exposure, was induced by 12-fold in the 4600 pg/g treatment relative to controls. The median lethal dose for chicken (Gallus domesticus) eggs we dosed identically to wood duck eggs was about 100 pg/g, similar to other assessments of chickens. Among dioxin-like compound embryo lethality data for 15 avian genera, the wood duck 4600 pg/g no-observed-effect level ranks near the middle. Because no higher doses were tested, wood ducks may be like other waterfowl (order Anseriformes), which are comparatively tolerant to embryo mortality from polychlorinated dibenzo-p-dioxins and dibenzofurans when exposed by egg injection.