DDT in fish from the Bulgarian region of the Black Sea

In spite of a worldwide reduction in the utilization of organochlorine pesticides (OCPs), they are still a problem for the aquatic environment and human health. The Black Sea is still being polluted with persistent chemicals, including OCPs. Aquatic organisms (sprat, scad, bluefish, shad, belted bonito, goby, and black mussel) with different feeding behaviours were sampled on a seasonal basis from the Bulgarian region of the Black Sea, and the concentrations of 13 OCP residues were determined. Although many of the OCPs were not detected in the samples, in all samples 1,1,1-trichloro-2,2-bis(4-chlorophenyl) ethane (DDT) was present mainly in the form of its metabolites 1,1-dichloro-2,2-bis(4-chlorophenyl) ethane (DDD) and 1,1-dichloro-2,2-bis(4-chlorophenyl) ethylene (DDE). Only about 12% of the total DDT was present as the parent compound pp-DDT, which suggests that it was not being used recently in the region. The total DDT concentrations were generally below 150 μg kg^-1 fresh weight, but higher levels—up to 354 μg kg^-1 fresh weight—were also measured for fish species with a high fat content. Between-species differences were observed, even when the concentrations were presented on a fat-level basis. DDT concentrations did not show any significant changes over the 2-yr sampling period. Fish sampled in the northern areas of the Bulgarian Black Sea coast seemed to contain higher DDT levels than those from the southern areas, suggesting a major (historical) influence of the Danube River. For permanent monitoring purposes, the utility of Black Sea gobies and scad should be considered.     

Estimates of animal methane emissions

The enteric methane emissions into the atmospheric annually from domestic animals total about 77 Tg. Another 10 to 14 Tg are likely released from animal manure disposal systems. About 95% of global animal enteric methane is from ruminants, a consequence of their large populations, body size and appetites combined with the extensive degree of anaerobic microbial fermentation occurring in their gut. Accurate methane estimates are particularly sensitive to cattle and buffalo census numbers and estimated diet consumption. Since consumption is largely unknown and must be predicted, accuracy is limited often by the information required, i.e., distribution of animals by class, weight and productivity. Fraction of the diet lost as enteric methane mostly falls into the range of 5.5–6.5% of gross energy intake for the world's cattle, sheep and goats. Manure methane emissions are heavily influenced by fraction of disposal by anaerobic lagoon. Non-ruminants, i.e., swine, become major contributors to these emissions.     

Community evacuation following a chlorine release, Mississippi

On 7th September 1986, four miles north of Collins, Mississippi, a train transporting chlorine derailed. Two cars ruptured and gas escaped. As a result, 100 families were evacuated. To study the evacuation process, we conducted person-to-person interviews with sixty-two families staying in the evacuation center. Only 52.5% of the families received their first directive to evacuate directly from police or other officials. Delays in evacuating tended to be shorter when people were warned by the police and were told the reason for evacuating. Lack of personal transportation and preexisting health problems resulted in delays in evacuation. Concerns about evacuation included fear of looting, lack of a place to go, lack of transportation, difficulty in moving with children and elderly persons, and the need to take care of pets. One third of the interviewees reported feeling panic. Community evacuation procedures would be improved if: (1) officials contact all households directly; (2) the warning message addresses people's concerns; and (3) transportation is provided.     

Simplicity versus efficiency in sampling designs and estimation

Simplicity and efficiency in design and estimation are all important in deciding on sampling strategies. A simple model is given and illustrated for four practical situations to show how a good sampling strategy should be selected.The U.S. Government right to retain a non-exclusive, royalty free licence in and to any copyright is acknowledged.     

A simple and effective approach for detecting maternal cell contamination in molecular prenatal diagnosis

The presence of maternal cells in fetal samples constitutes a serious potential source for prenatal misdiagnosis. Here we present our approach for detecting maternal cell contamination (MCC) at prenatal diagnosis for eight monogenic disorders (autosomal recessive: β-thalassaemia, sickle-cell anaemia, cystic fibrosis, prelingual deafness; autosomal dominant: achondroplasia, Huntington disease, myotonic dystrophy, neurofibromatosis type I; X-linked: spinobulbar muscular atrophy). Our aim was to apply a simple and low-cost approach, which would easily and accurately provide information on the fetal tissue MCC status. MCC testing was applied to cases of recessive inheritance where the primary mutation screening of the fetus revealed the presence of the maternal mutation, to cases concerning dominant inheritance and to cases of multiple gestation. The potential presence of maternal cells was determined by the amplification of the 3′-HVR/APO B, D1S80, THO1 and VNTRI of vWf polymorphic loci, which have previously demonstrated high heterozygosity in Caucasians. Among 135 prenatal diagnoses, 44 finally needed to be tested for MCC (32.6%). MCC was detected in four cases, where DNA was isolated directly from chorionic villi samples (CVS), and in one case with DNA isolated directly from amniotic fluid (AF). In almost 90% of cases a simple test of one polymorphic locus provided sufficient information about MCC. The choice of the appropriate locus is therefore essential, while the simultaneous screening of both parents provides the means for distinguishing non-informative sites about MCC. Copyright © 2002 John Wiley & Sons, Ltd.     

Sustainability: a Dissent

Abstract:  Broadly conceived and considered in its many usages, sustainability has grave defects as a planning goal, particularly when used by conservationists: it confuses means and ends; it is vague about what is being sustained and who or what is doing the sustaining; it is uninspiring; it is little more than Pinchot-era conservation (and thus ignores the many lessons learned since then); it need not be linked to land, to the land's functioning, or to any ecological science; it need not include a moral component; it is consistent with the view of humans as all-powerful manipulators of the planet; and, in general, it is such a malleable term that its popularity provides only a facade of consensus. When sustainability is defined broadly to include the full range of economic and social aspirations, it poses the particular risk that ecological and biodiversity concerns will be cast aside in favor of more pressing human wants. Given these many defects, the conservation movement should discard the term in favor of a more alluring goal, attentive to nature and its ecological functioning. A sound goal would incorporate and distill the considerable ecological and moral wisdom accumulated since Pinchot's day while giving conservationists the rhetorical tools needed to defend the land against competing pressures. In our view, conservation would be well served by an updated variant of "land health," Aldo Leopold's ecologically grounded goal from the 1940s. Land health as an independent understanding should set the essential terms of how we live and enjoy the earth, providing the framework within which we pursue our many social and economic aims.