Characterisation of potentially genotoxic compounds in sediments collected from United Kingdom estuaries

The mutagenic activity bioassay Mutatox was used to assess the mutagenic activity associated with sediments collected from five UK estuaries. Assays were performed on extracts of sediment pore water and residual particulate material isolated from sediment samples collected from the rivers Tyne, Tees, Mersey, and Thames as well as Southampton Water. No mutagenic activity was associated with the pore water extracts, however, 7 of the 28 organic solvent extracts of sediment particulate material contained potential genotoxins. By using Mutatox in association with bioassay-directed fractionation, attempts were made to identify the mutagenic compounds present in the extracts. The fractionation procedure used normal phase solid phase extraction, C18 reverse phase HPLC and cyano/amino bonded silica normal phase HPLC. GC-MS (EI and NICI) analysis was used to identify polycyclic aromatic hydrocarbons (PAH), alkyl substituted PAH, nitro-polycyclic aromatic compounds (nitro-PACs), polycyclic aromatic ketones, oxygenated-PACs, and other known mutagens contributing to the genotoxicity measured in the samples. Some potentially genotoxic compounds remain unidentified.     

Reduced survival and body size in the terrestrial isopod Porcellio scaber from a metal-polluted environment

Terrestrial isopods (woodlice) may show trade-offs in life history parameters when exposed to toxins. We have shown previously [Jones and Hopkin (1996) Functional Ecology 10, 741-750] that woodlice which survive to reproduce in sites heavily polluted with metals from an industrial smelting works do not alter their reproductive allocation. This study investigates whether there are differences in the survival and body size of Porcellio scaber from these same populations. Specimens were collected from eight sites at different distances from the Avonmouth smelter, UK. The sites represented a gradient of concentrations of Zn, Cd, Pb and Cu in the woodlice, from background levels to a grossly contaminated sites close to the smelter. In laboratory trials, the number of days survived by starved males showed a significant decline with increased concentrations of Zn in those animals. The maximum size of both sexes declined significantly from the least to the most polluted sites. The most polluted sites had significantly fewer large animals. The cost of detoxifying assimilated metals appears to be reduced energy reserves and smaller body size.     

The influence of sewage sludge applications to agricultural land on human exposure to polychlorinated dibenzo-p-dioxins (PCDDs) and -furans (PCDFs)

Polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) are organic chemicals of suspected extreme toxicity. PCDD/Fs are ubiquitous in the environment and relatively enriched in sewage sludges. The deliberate application of sewage sludge to agricultural land can therefore potentially increase exposure of the human population to these compounds via transfers through the foodchain. This paper presents a protocol for assessing the background human exposure to all seventeen 2,3,7,8-substituted PCDD/Fs for which toxic equivalent factors (TEFs) are available. Background daily human exposure in the UK to 2,3,7,8-T(4)CDD and I-TEQ are calculated to be 0.0239 ng and 0.203 ng, respectively. The potential increases in crop plant and livestock tissue PCDD/F concentrations, and hence in human exposure, following applications of sewage sludge to agricultural land are quantified for different sludge application scenarios. The key role of PCDD/F transfer into livestock via ingestion of sludge adhered to vegetation in determining increases in human exposure is demonstrated.     

Polybrominated diphenyl ethers and selected organochlorine chemicals in grey seals (Halichoerus grypus) in the North Sea

Blubber samples from grey seal (Halichoerus grypus) pups were collected in 1998 through to 2000. Twenty four newly weaned pups were sampled in November 1998, 13 of which were re-sampled during their first year of life, between March and December 1999, and an additional 48 and 25 samples (new cohorts) were obtained in 1999 (November-December) and 2000 (May-September) respectively. SimgaPBDE concentrations (sum of Di-HxBDEs) ranged from 45 to 1500 ng/g lipid, with a geometric mean of 290 ng/g lipid. BDE 47 dominated the congener profile, followed by BDEs 100, 99, 153 and 154. SimgaPCB concentrations (sum of 41 congeners) ranged from 100 to 93000 ng/g lipid, with a geometric mean of 4600 ng/g lipid, with CB congeners 153, 138 and 180 making up 84% of the total PCB concentrations. The predominant OC pesticides were p,p'-DDE (geometric mean=860 ng/g lipid, range=160-3800 ng/g lipid) and p,p'-DDT (geometric mean=120 ng/g lipid, range=30-670 ng/g lipid). No significant differences were found between males and females, probably due to the young age of the animals. Significant decreases (P<0.01 for PBDEs and P<0.05 for PCBs/OCs) were observed between newly weaned seals in 1998 and 1999, but not for the majority of juveniles in 1999 and 2000. Significant differences (P<0.01) were also found between the different seasons in 1999 newly weaned and juvenile seals, reflecting changes in blubber mass.     

Toxicity of crude oil to the mayfly, Hexagenia bilineata (Ephemeroptera: Ephemeridae)

Effects of crude oil on survival and behavior of the mayfly Hexagenia bilineata were evaluated in laboratory studies. Mayfly nymphs were exposed to the water soluble and oil residue fractions of crude oil. Mayfly survival was not reduced by a 96-h exposure to either the water soluble fraction or the oil residue mixed with sediment. However, significant mortality did result from a 21-day exposure to oil residue mixed with sediment at concentrations as low as 500 microg g(-1). Survival was also reduced after a 21-day exposure to oil-contaminated sediments (1905 microg g(-1)) collected 6 weeks after a crude oil spill in the Chariton River, Missouri. In a behavioral test measuring habitat exclusion, organisms did not avoid contact with sediment containing oil residue (50-800 microg g(-1)). Collectively, results from these studies indicate that exposure to oil residue in sediment will reduce survival of H. bilineata in the laboratory and may reduce survival in the environment for 6 weeks or more after an oil spill.     

Prenatal sonographic diagnosis of metastatic neuroblastoma: Report of a case and review of the literature

Congenital malignant tumours are rare. Neuroblastoma is the most common solid tumour, accounting for about 30–50 per cent of tumours evident during the neonatal period. A case of metastatic, rapidly growing neuroblastoma, diagnosed prenatally by ultrasound at 32 weeks' gestation, is presented.     

Tibial hemimelia syndrome: Prenatal diagnosis by real-time ultrasound

The tibial hemimelia syndrome is a rare autosomal dominant condition associated with limb deficiencies. We recently diagnosed this condition in a pregnancy at 16·5 weeks' gestation by ultrasound and a positive family history. To our knowledge, this represents the first case to be detected prenatally.     

Three-dimensional ultrasound in prenatal diagnosis of skeletal dysplasia

A lethal form of bone dysplasia, platylospondylic lethal chondrodysplasia, was diagnosed prenatally using three-dimensional ultrasound. The various types of three-dimensional imaging mode provided diagnostic details not available by conventional two-dimensional ultrasound. The diagnosis was made after referral in the 23rd week of gestation, allowing termination of pregnancy due to the poor prognosis. Prenatal sonograms were compared with postnatal radiographs.     

Maternal serum biochemical markers in pregnancies with fetal parvovirus B19 infection

Hydrops fetalis and fetal death caused by fetal parovirus B19 infection have been reported to be associated with elevated maternal serum alpha-fetoprotein (AFP), based on a total of six cases. It has been suggested that the absence of AFP elevation may be reassuring. Maternal serum levels of the Down syndrome screening markers unconjugated oestriol and human chorionic gonadotropin in cases of fetal parvovirus infection have not been previously reported. We report four cases of hydrops fetalis and fetal death caused by fetal parvovirus infection, each with unremarkable second-trimester levels of AFP, unconjugated oestriol, and human chorionic gonadotropin.