Arrested municipal solid waste incinerator fly ash as a source of heavy metals to the UK environment

Arrested fly ash samples from most currently operating municipal solid waste (MSW) incinerators in the UK have been analysed for a range of elements. Some of the more important heavy metals ranged in concentration as follows: Cd, 21-4646 (median = 271) mg kg(-1); Cu, 296-1307 (642) mg kg(-1); Cr, 44-1328 (574) mg kg(-1); Ni, 45-2204 (74) mg kg(-1); Pb, 447-9704 (4337) mg kg(-1); and Zn, 2285-13,500 (9232) mg kg(-1). These concentrations represent considerable enrichments relative to median UK soil concentrations. Enrichment ratios (defined as median fly ash: median UK soil) were as follows: Mn 1.6; Co 2.6; Ni 3.3; Ba 11; Sr 11; Cr 15; Cu 35; Pb 108; Zn 113; Cd 387. It is estimated that MSW incinerator ash contributes c. 15 t Cd and 241 t Pb to UK landfill sites per annum. These figures compare with previous studies by Hutton & Symon (Hutton, M. & Symon, C. (1986). The quantities of cadmium, lead, mercury and arsenic entering the UK environment from human activities. Sci. Total Environ., 57, 129-50.) which estimated that annual inputs to UK landfills from coal fly ash are c. 60 t Cd and 1270 t Pb. However, it is argued that metals associated with MSW ashes are potentially of greater environmental significance than in coal ashes, because they are much more available and present at much higher concentrations.     

The persistence of polynuclear aromatic hydrocarbons (PAHs) in sewage sludge amended agricultural soils

In 1968, five metal enriched sewage sludges containing different concentrations of polynuclear aromatic hydrocarbons (PAHs) were applied to different plots on field soils at two experimental sites, Luddington and Lee Valley, in the UK. This resulted in substantial increases in the total PAH soil concentrations in all plots. Since application, losses have occurred, with the high molecular weight PAHs being more persistent. Calculated half-lives range from under 2 years for naphthalene to over 9 years for benzo[ghi]perylene and coronene. The losses of PAH compounds in these field experiments can be related, in part, to their physico-chemical properties, notably the octanol: water partition coefficient.     

Phenolic water pollutants in a Malaysian River basin

Phenolic chemicals with their very low taste and odour thresholds, high persistence and toxicity, are of growing concern as water pollutants. The compounds are known to exist in raw water as well as in treated water. The level of phenolic priority pollutants in water within the catchment area of the Linggi River Treatment Plant in Negeri Sembilan, Malaysia, which includes the Linggi river basin, was monitored. The 4-aminoantipyrin colourimetric method was used to determine total phenols whereas capillary column gas chromatography was used to determine the individual compounds. The results show that at most sampling stations, particularly those within the Seremban municipality, the level of phenols was found to exceed the recommended Malaysian standard of 2.0 g/L^-1 for raw water. This is seen as the direct impact of industrial and urbanization of the area and clearly indicates the unhealthy state of the Linggi river. The results also indicate the need to improve the water quality if the river is going to be used as a source of raw water.     

The microbial role in hot spring silicification

Recent experimental studies indicate that microorganisms play a passive role in silicification. The organic functional groups that comprise the outer cell surfaces simply serve as heterogeneous nucleation sites for the adsorption of polymeric and/or colloidal silica, and because different microorganisms have different cell ultrastructural chemistry, species-specific patterns of silicification arise. Despite their templating role, they do not appear to increase the kinetics of silicification, and at the very most, they contribute only marginally to the magnitude of silicification. Instead, silicification is due to the polymerization of silica-supersaturated hydrothermal fluids upon discharge at the surface of the hot spring. Microorganisms do, however, impart an influence on the fabric of the siliceous sinters that form around hot spring vents. Different microorganisms have different growth patterns, that in turn, affect the style of laminations, the primary porosity of the sinter and the distribution of later-stage diagenetic cementation.     

Die Aleuronzellen des keimenden Getreides

Während der Vorbereitungen zu diesem Artikel war R. L. J. als Preisträger der Alexander-von-Humboldt-Stiftung in Göttingen tätig. Unsere Forschung auf diesem Gebiet wurde durch großzügige Hilfe der Deutschen Forschungsgemeinschaft und der National Science Foundation (USA) ermöglicht. Außerdem sind wir B. Raufeisen für die Herstellung der Zeichnungen sehr zu Dank verpflichtet.     

Towards an alternative criterion for the shipping safety of activated carbons

A new criterion for shipping safety of activated carbons is developed which requires microcalorimetric measurements for its implementation. It is examined by making microcalorimetric measurements on a variety of commercial activated carbons. Results are compared with those for the same carbons according to the critical ignition temperature approach.     

Early prenatal direct gene diagnosis of cystic fibrosis in a twin pregnancy and subsequent selective termination

We present a case of prenatal diagnosis of cystic fibrosis (CF) in one twin at 11–12 weeks of gestation. The parents had previously had two children, one of whom is alive and healthy and one who died of CF at the age of 2½ months. The parents were both known to be carriers of the ΔF508 mutation. Chorionic villus sampling (CVS) was performed and direct gene analysis showed that one fetus was homozygous for the ΔF508 mutation, while the other fetus did not have the mutation at all. Both fetuses had normal karyotypes. Selective termination was subsequently performed. The pregnancy continued without complications except for mild pre-eclampsia at term. The woman had a Caesarean section. The genetic diagnosis was confirmed after birth.     

Mosaic triple trisomy in amniocytes from a phenotypically and karyotypically normal fetus

We report the detection of a mosaic triple trisomy, 46, XY/49, XY, + 13, +20, +21, in two amniotic fluid specimens obtained from a pregnancy that yielded a normal infant. Traditional cytogenetic methods failed to detect the abnormal cell lineage in fetal blood, foreskin, amnion, umbilical cord, and three different biopsies of the chorion. In addition, fluorescence in situ hybridization study of cells from a buccal smear showed no evidence of cells with three copies of chromosome 20.