For the 1983 nesting season, Forster's tern (Sterna forsteri) reproductive success was significantly impaired on organochlorine contaminated Green Bay, Lake Michigan compared to a relatively uncontaminated inland location at Lake Poygan, Wisconsin. Compared with tern eggs from Lake Poygan, eggs from Green Bay had significantly higher median concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), other polychlorinated dibenzo-p-dioxins (PCDDs), total polychlorinated biphenyls (PCBs), total (three congeners) non-ortho, ortho' PCBs, five individual PCB congeners known to induce aryl hydrocarbon hydroxylase (AHH) and several other organochlorine contaminants. Conversions of analytical concentrations of TCDD and PCB congeners based on relative AHH induction potencies allowed for estimation of total 2,3,7,8-TCDD equivalents. Two PCB congeners, 2,3,3',4,4'- and 3,3',4,4',5-pentachlorobiphenyl (PeCB) accounted for more than 90% of the median estimated TCDD equivalents at both Green Bay and Lake Poygan. The median estimated TCDD equivalents were almost 11-fold higher in tern eggs from Green Bay than in eggs from Lake Poygan (2175 and 201 pg/g). The hatching success of Green Bay sibling eggs from nests where eggs were collected for contaminant analyses was 75% lower at Green Bay than at Lake Poygan. Hatchability of eggs taken from other nests and artificially incubated was about 50% lower for Green Bay than for Lake Poygan. Among hatchlings from laboratory incubation, those from Green Bay weighed approximately 20% less and had a mean liver weight to body weight ratio 26% greater than those from Lake Poygan. In both field and laboratory, mean minimum incubation periods were significantly longer for eggs from Green Bay compared to Lake Poygan (8.25 and 4.58 days, respectively). Mean minimum incubation time for Green Bay eggs in the field was 4.37 days longer than in the laboratory. Hatchability was greatly improved when Green Bay eggs were incubated by Lake Poygan adults in an egg-exchange experiment, but was sharply decreased in Lake Poygan eggs incubated in Green Bay nests. Nest abandonment and egg disappearance were substantial at Green Bay but nil at Lake Poygan. Thus, not only factors intrinsic to the egg, but also extrinsic factors (parental attentiveness), impaired reproductive outcome at Green Bay. The epidemiological evidence from this study strongly suggested that contaminants were a causal factor. AHH-active PCB congeners (intrinsic effects) and PCBs in general (extrinsic effects) appeared to be the only contaminants at the concentrations measured in eggs, capable of producing the effects that were observed at Green Bay.

No abstract

This study was designed to determine the effects of various environmental factors on the deoxyribonucleic acid (DNA) obtained from dental pulp. Extracted teeth were subjected to the following conditions: varying pH (3.7, 10); temperature (4°C, 25°C, 37°C, incineration); humidity (20%, 66%, 98%); various types of soil (sand, potting soil, garden soil); seawater; burying the teeth outdoors, and aging (one week to six months). In addition, teeth that had been extracted and held at room temperature for 16 and 19 years were also examined. Following isolation of DNA, the samples were analyzed on yield gels to determine the concentration and integrity of the recovered DNA. Restriction digestion with Pst I was followed by electrophoresis of the generated fragments, Southern transfer to nylon membranes, and hybridization to both human and bacterial probes. It was determined that, aside from soil, the environmental conditions examined did not affect the ability to obtain high-molecular-weight human DNA from dental pulp. Restriction fragment length polymorphic (RFLP) analysis of selected samples was performed. Dental pulp patterns were compared with bloodstain exemplars, revealing matching patterns, although an increase in band-shifting was observed with extended exposure to elevated temperatures.

No abstract

No abstract

No abstract

Elevated concentrations of planar, halogenated hydrocarbons have been linked to reproductive problems in a variety of fish-eating birds and mammals in the Great Lakes and in particular Saginaw Bay. Currently, there are no accurate procedures to assess bioavailability of these contaminants. Polychlorinated dibenzo-p-dioxins and dibenzofurans and mono- and non-ortho-chloro-substituted biphenyls in water at the femtogram to picogram per liter range were passively concentrated in semipermeable membrane devices (SPMDs), and these data were compared to the bioconcentration in co-exposed (caged) channel catfish. Sediment-derived water concentration estimates, calculated from a steady-state partitioning model, did not correlate well to those derived from either fish or SPMDs. The use of SPMDs demonstrated the utility of in-situ passive sampling over inference of water concentrations from accumulation in biota or partitioning with sediment. Residues ac cumulated by SPMDs have been shown to be proportional to analyte water concentration, whereas this does not appear to be the case for fish tissues. The greater amounts of 3,3‘,4,4‘-tetrachlorobiphenyl and 2,3,7,8-tetrachlorodibenzofuran accumulated in SPMDs than in exposed channel catfish indicated those non-passive aspects of bioconcentration in organisms, such as biotransformation and elimination, introduced 50−500% error in the assumed degree of exposure.

A technique Is proposed for the quantitative determination of constituents In complex mixtures characterized by gas chromatography data. The technique Is partial least squares In latent variables (PLS) and the data to which It Is applied are gas chromatograms of the Aroclors 1242, 1248, 1252, and 1260. In addition the problem Is formulated as one of classification and calibration and a sample of used transformer oil from a waste dump Is classified as to Its origin.