Human Settlements on the Northern Shores of Lake Aral and Water Level Changes

The shore of Lake Aral in Kazakhstan is a perfect area for studying the human adaptation strategy to past climate changes. New archaeological material, gathered along the northern shores during the expedition of the INTAS project CLIMAN, is briefly presented. Changes in settlement activity during the Atlantic and Subboreal are related to lake level changes of the Aral Sea. A previ-ously proposed lake level maximum needs to be revised. In particular the lake level stand at 72/73 m, with an assumed age of 5000 BP is definitely refused. Based on the presented data the maximum lake level most probably never reached beyond 57/58 mean average sea level (masl). Furthermore the regression during the 15^th–16^th centuries has been underestimated. It may have been lower than the present day level. Thus the present desiccation of the Aral Sea is historically not unique, as a similar regression, probably induced by man as well, has occurred at least once during history. A readjustment of the water level is, therefore, possible at any time.     

Analyse frühgeschichtlicher Gefäßinhalte

Informations on the contents of prehistoric vessels were up to now obtained by occasional findings of residues recognizable by botanists. Recently the application of a method of food analysis, the fat determination, considerably broadened the possibilities, for from almost every potsherd fat can be extracted. Difficulties arise by the decomposition of old fats, which can be overcome by simulations in the laboratory or by extraction of fat from old findings which are determined by the botanist or zoologist.     

DNA-based prenatal diagnosis of the infantile form of neuronal ceroid lipofuscinosis (INCL,CLN1)

Eleven fetuses at risk for the infantile form of neuronal ceroid lipofuscinosis (INCL, CLN1) were studied using DNA markers and the results were compared with the results of electron microscopy (EM) of chorionic villus specimens from pregnancies in the first or early second trimester of pregnancy. In four cases, the prenatal diagnosis was made independently with both methods, and in seven cases, the EM diagnosis was confirmed postnatally or from autopsy material using RFLP analysis. The two methods gave concordant results in all cases. The DNA analysis based on RFLP haplotypes also for the first time facilitates reliable carrier diagnostics. RFLP analysis based on polymorphic markers closely linked to the INCL locus is now available for prenatal diagnosis of this fatal brain disease, whose biochemical background is totally unknown and for which no treatment is available.     

Verunreinigte Böden

This article discusses the evaluative criteria which are applied for the assessment of contaminated soils. Guide values for materials in the soil (reference values, test values and action levels). Such guide values can be derived based upon either functional or constitutional criteria. The leachate from the soil must be analyzed for noxious materials in order to ensure the conservation of both ground- and surface-waters. Furthermore, existing concepts and drafts for evaluating soil contamination are discussed. The great diversity of the 37 regulatory publications for evaluating soil contamination is due to 1. different purposes these guidelines are aimend at, and 2. varying philosophies with regard to the degree of safety which is considered to be acceptable:

1. The approach of the LAGA (Länderarbeitsgemeinschaft Abfall-German federal cooperative for waste regulation) is to merely avert dangerous effects of polluted land rather than to take precautionary measures.
2. The approach of the state of Baden-Württemberg is to combine precautionary activities and defensive procedures in one scheme with the technical and financial feasibility as criteria for the final decision.

A summary of the valid legislation is discussed, based on the specific regulatory works of the individual German states:

- The federal soil protection act and the directives based on it

- Inherent problems with deriving test values from basic toxicological data as well as the question of a tolerable cancer risk level

The procedure of linking the test values with a concrete danger to health that was designed for the federal soil protection act is discussed and compared with an alternative procedure. A presentation is given of the LABO (Länderarbeitsgemeinschaft Bodenschutz — German federal and state cooperative on soil conservation) utilization concept for soils: The use of test values for assessing soil materials with regard to particular utilization goals. The article quotes the ?Guideline for monitoring the success in soil cleanup operations” as compiled by the GDCh working group on ?Environmental chemistry and ecotoxicology” (1996). This guideline provides a review of the evaluatory concepts applied in the German states of Hamburg, North Rhine-Westphalia, Brandenburg, Rhineland-Palatinate, Hessen, Baden-Württemberg, as well as those of the German federal cooperative for waste regulation (LAGA). The respective procedures and specifications of Holland, Canada, the USA are also noted in this guideline.     

Tetrachloroethylene emissions and exposure in dry cleaning

Tetrachloroethylene (PCE) emissions and the exposure of workers in six commercial and three industrial dry-cleaning establishments that use dry-to-dry machines were determined. The personal samples and area samples [8-hr time-weighted average (TWA) and short-term exposure] were collected with charcoal tubes and passive monitors. The temporal variation of PCE concentration in the workplace air was monitored using a Fourier transform infrared analyzer (FTIR). The PCE emission rates were determined by multiplying the average PCE concentration in the room and the total airflow rate in the room. The PCE emissions were related to the cleaning rate in units of kg/hr. The operators' mean TWA exposure in commercial shops and industrial establishments was 28 (4.1 ppm) and 32 mg/m3 (4.6 ppm), and the pressers' exposure was 3.4 (0.5 ppm) and 7.7 mg/m3 (1.1 ppm), respectively. The customer service personnel had the lowest TWA exposure with a mean value of 0.8 mg/m3 (0.1 ppm). The highest peak concentration (2300 mg/m3; 334 ppm) was observed during cleaning of the lint and button trap, during which operation respirators were used. The PCE emission rates ranged from 4 to 118 g/hr corresponding to emission factors (mass of solvent evaporated per mass of cleaned cloths) of 0.3-3.6 g/kg. The workers' exposure to PCE was below the occupational limit values in the United States [according to the American Conference of Governmental Industrial Hygienists (ACGIH)] and in Finland. The outdoor PCE emissions were clearly below the limit values given in the European Union volatile organic compound (VOC) directive requirements.     

Monitoring and modelling of biosphere/atmosphere exchange of gases and aerosols in Europe

Monitoring and modelling of deposition of air pollutants is essential to develop and evaluate policies to abate the effects related to air pollution and to determine the losses of pollutants from the atmosphere. Techniques for monitoring wet deposition fluxes are widely applied. A recent intercomparison experiment, however, showed that the uncertainty in wet deposition is relatively high, up to 40%, apart from the fact that most samplers are biased because of a dry deposition contribution. Wet deposition amounts to about 80% of the total deposition in Europe with a range of 10-90% and uncertainty should therefore be decreased. During recent years the monitoring of dry deposition has become possible. Three sites have been operational for 5 years. The data are useful for model development, but also for model evaluation and monitoring of progress in policy. Data show a decline in SO(2) dry deposition, whereas nitrogen deposition remained constant. Furthermore, surface affinities for pollutants changed leading to changes in deposition. Deposition models have been further developed and tested with dry deposition measurements and total deposition measurements on forests as derived from throughfall data. The comparison is reasonable given the measurement uncertainties. Progress in ozone surface exchange modelling and monitoring shows that stomatal uptake can be quantified with reasonable accuracy, but external surface uptake yields highest uncertainty.