[Ultrathin-layer starch gel electrophoresis--a method qualified to solve specific problems in enzyme analysis]. / Die Ultradünnschichtstärkegelelektrophorese--ein geeignetes Verfahren zur Lösung spezifischer Probleme der Enzymanalytik.

Particular separation problems of enzymatic analysis led to optimization investigation on starch gel electrophoresis. Investigations on the optimum gel concentration range a well as on the duration of the hydrolysis of starch for a suitable gel network gave rise to a starch level with good molecular sieve effect. Optimization of the electrophoretic buffer system and the development of an optimum technique for manufacturing handy transparent ultra thin-layer starch gels with high selectivity results for a broad spectrum of diagnostically enzymatic systems has turned out to be of advantage for enzymatic electrophoresis.

[Arsenic emission and effects on the biosphere]. / Arsen-Immissionen und deren Auswirkungen auf die Biosphäre.

In the GDR, the arsenic emission in the surroundings of metallurgical plants have been reduced to a minimum, the contamination of the soil being not yet diminished in some cases. In the framework of a comprehensive research program, it was shown that the uptake of arsenic by man via the food chain is possible in the area of activity of an arsenic emitter (due to increased arsenic content in the sedimentary dust), even if the maximum emission concentration of arsenic in the aerosol is considerably lower than the permanent limit value. Apart from local sources of emission (e.g. non-ferrous smelteries and phosphate works), the extended burden on the air by traces of arsenic originating from power station exhalates deserves increasing attention. In regions where industrial plants are concentrated, but also in regions with intensive agriculture and horticulture, it is recommendable to determine regularly the arsenic contents in the air, soil, vegetable feeding stuffs and vegetable foodstuffs.

[Heavy metal content of cereals and potatoes]. / Untersuchungen zum Schwermetallgehalt von Getreide und Kartoffeln.

By means of atomic absorption spectrometry, the authors determined the cadmium, zinc, copper and manganese contents in potatoes and cereals from three territories differently burdened by heavy-metal immissions (rural region, overcrowded urban region, region with non-ferrous metal industry). Of these elements, cadmium was most enriched, followed (by a wide margin) by zinc and copper, whereas the manganese level was slightly higher in the burdened region II (compared to the burdened region I) and somewhat lower in the burdened region III. Compared to normal values (0.035--0.080 p.p.m.), i. e., values found in non-burdened regions, the cadmium contents were some 2- to 6-fold higher in air-dry samples of wheat, barley and rye from the burdened regions, some 30-fold higher in oats, and some 3- to 4-fold higher in potatoes (normal values, on a dry-weight basis, (0.140 p.p.m.). As to cereals, the zinc levels were, at the most, some 2-fold higher than the normal values (29--34 p.p.m.), the copper contents were, at the most, some 1.5-fold higher than the normal values (4.1 bis 4.8 p.p.m.), whereas the manganese levels (normal values, 14--30 p.p.m.) were less by half. In potatoes, the zinc contents were but slightly higher than the normal values (18.5 p.p.m., on a dry-weight basis), the copper levels (4.6 p.p.m., on a dry-weight basis) were some 2-fold higher, and the manganese contents (7.2 p.p.m., on a dry-weight basis) were somewhat reduced. On an average 26% (region with non-ferrous metal industry) or 13% (normal region) of the heavy metals are removable from potatoes by washing. On the basis of the results obtained and of data from the literature, an estimate is calculated for the expected values in territories differently burdened by heavy-metal immissions. Finally, targeted suggestions are given for preventing or impeding the entrance of heavy metals into the biocycle.

[Cadmium content of vegetable foods in the effective range of a lead smelting plant]. / Cadmiumgehalt pflanzlicher Nahrungsmittel im Wirkungsbereich einer Bleihütte.

In the effective range of a lead smelting plant, the repercussions of cadmium emissions (mainly past) on vegetables, fruit, soil and drinking water as well as of immissions were investigated by means of atomic absorption spectrometry. As compared to the "normal" cadmium level, the cadmium contents in vegetables and fruit were some 2- to 85-fold higher; and those in soils, some 70- to 230-fold. The mean contents in vegetables ranged from 0.4 to 25.5 p.p.m. (on a dry-weight basis); those in fruit, from 0.09 to 1.17 p.p.m. Cadmium concentrations varying from 6.8 to 22.8 p.p.m. were found in soil samples. The drinking water contained 0.009 p.p.m. of cadmium. The mean cadmium contents in the atmosphere and the sedimentary dust were 0.007 mg/m3 and 0.550 mg/m2/30d, respectively. In the territory investigated, the total human uptake of cadmium supplied by vegetables, fruit, potatoes, drinking water and air is 3.3-32.6 microgram/d. The following cadmium levels were found in human organ samples obtained at necropsy: right and left renal cortex, 33.99 and 35.98 p.p.m., respectively; liver, 3.14 p.p.m.; lungs, 0.63 p.p.m.; pancreas, 1.47 p.p.m.; brain stem, 0.16 p.p.m.

[Evaluation of the cadmium content in sedimented and floating dust as factors in contamination of the biosphere]. / Bewertung des Cadmiumgehaltes im Sedimentations- und Schwebstaub als Faktoren der Kontamination der Biosphäre.

In a territory being 3.500 km2, the cadmium deposits from the atmosphere were determined at 63 sites in 52 towns and communities. These determinations yielded a mean value ranging from 0.13 to 0.15 mg/m2 . 30 d. On the contrary, the mean value (-x) was 0.33 mg/m2. 30 d in the region of heavy-metal-emitting industries. The mean cadmium content in the aerosol was between 0.003 and 0.004 microgram m-3 and, respectively, 0.016 microgram m-3 in case of cadmium emission. It was calculated that the mean proportion of cadmium in the sedimentary dust was between 13 and 16 p.p.m. The cadmium burden, as estimated as cadmium sediment, correlated with the extent of the developmental area. The authors recommend for the present the following maximum permissible values: 0.05 microgram m-3 in the aerosol, and 0.15 mg/m2. 30 d. The cadmium content in the sedimentary dust may be considered to be a permanent burden applied via the food chain, whereas the content in the aerosol is of less importance to the total uptake in man. The calculation of the daily pulmonary uptake yielded a value of 0.075 microgram, from which an absorption of 0.038 microgram is estimated.