Lead and cadmium in teeth,bone and kidneys of rats with a standard Pb‐Cd supply

Male Wistar rats received a combination of 25 ppm PbCl₂ and 5 ppm CdCl₂ in drinking water at different developmental stages. Pb and Cd levels of incisors, molars, epiphyses, diaphyses and kidney cortex were recorded by atomic absorption spectrophotometry. The results confirmed that Pb has an affinity for hard tissue and especially to teeth, but it also accumulated in soft tissues under the above conditions. In addition, the results indicated none or only a moderate placental or mammary barrier for Pb, and suggested a high absorption of lead from the intestine of sucklings. The results also confirmed that kidney cortex is a primary target for Cd, and indicated that Cd has crossed the placental and mammary barriers to some degree. The positive significant correlation between Cd levels in molars and kidney cortex suggested that rodent molars indicate a degree of Cd absorption, whereas incisors do not. It is supposed that rodent molars are comparable to human deciduous teeth. It is thus confirmed that human deciduous teeth indicate previous lead exposure. It is further inferred that they also can be used as indicators of previous Cd‐exposures.     

The culture gap and its needed closures

The development of an enormous culture gap, in which no individuals of advanced societies possess even a billionth of the non‐genetic information possessed by their entire society, has threatened a global collapse of civilisation. Critical parts of that gap must be rapidly bridged so that problems such as climate disruption, toxification of the Earth, loss of biodiversity and ecosystem services, and the decay of the epidemiological environment can be satisfactorily attacked. The essential need is to alter human behaviour to put society on a route to sustainability; one cheering development is a growing interest in the Millennium Assessment of Human Behaviour (MAHB), whose goal is to do just that.     

An environmental purpose artificial island off Belgium

Processing municipal and industrial wastes on land and particularly near inhabited centra has met with increased opposition. An apparent remedy to the problem is the establishment of such facilities offshore, hence various projects to build them on artificial islands. The paper examines a concrete proposal to locate such an island offshore from the Belgian Coast. Oceanographic and environmental aspects of the site are discussed, construction methods reviewed, erosion and corrosion effects looked at. The possibility of utilizing ocean power to provide the necessary operation energy is likewise considered.     

Using Landscape Characteristics for Targeting Habitat Conservation and Restoration: A case study of ancient semi-natural woodland in the Chiltern Hills Area of Outstanding Natural Beauty,UK

Ancient semi-natural deciduous woodland is a rare and threatened habitat cited by the European Union's Habitats Directive (92/43/EEC). Current protection of this endangered habitat in the UK takes the form of site-specific reserve designations but, if the habitat is to be conserved and enhanced, a landscape-scale selective targeting system is required. In the absence of suitable species data, physical attributes of habitat patches are used as surrogate indicators of biodiversity. Using a land-use database held on a geographical information system, values of four abiotic criteria (patch area, patch shape, nearest-neighbour distance and surrounding land use) of 48 ancient semi-natural woodland patches in part of the Chiltern Hills Area of Outstanding Natural Beauty were calculated. In order to validate the findings, three lists of floral and faunal species, indicative of ancient semi-natural woodland, were compiled, and the patches ranked according to their alpha diversity using each list. Spearman's rank correlation coefficients were calculated for patch alpha diversity and patch area (0.322 to 0.482), patch shape (0.275 to 0.465) and nearest-neighbour distance ( - 0.092 to - 0.223). Multiple regression indicated that between 15 and 22% of the variation in alpha patch diversity was explained by the abiotic factors. It is suggested that spatial targeting at the landscape scale is a valuable approach to habitat conservation.     

‘Assessing the visual impacts of urbanization from the highway: a visual evaluation of the South Fork interchange site,North Bend,Washington’

This study is noteworthy as an application at project design scale of a methodology developed in 1976 by Jones & Jones for the Federal Highway Administation course ‘Esthetics and Visual Resource Management’ currently being given to highway professionals around the country. It also demonstrates the transfer of this methodology from highway facilities to urbanization.