Roughly three months after a swimming bath had been put into operation a growth was observed on the permanently elastic joints made of plastic material at the bottom of the pool. Samples were taken and examined and bacteria, fungi, green algae as well as many monocellular organisms were found. The repeated identification of a pathogenic dermatophyte and of P. aeruginosa was of hygienic significance.
The city of Antofagasta (northern Chile), is an area of endemic chronic arsenic poisoning due to arsenic-polluted drinking water. In order to explore the possibility of a dose-response relationship, a dietary survey was carried out in 1972 in that city for measuring the daily fluid intake in the various age groups. The sample (N = 220) included 13 males and 13 females in each age group, except the 81-90 year-old group with 6 males and 6 females. A linear relationship was found between arsenic dose (mg/kg body weight/day) and age for males being P less than 0.001 (slope) and r = -0.6712; and for females P less than 0.001 (slope) and r = 0.6667. Age-specific prevalence rates per 100,000 population (both sexes combined) for chronic arsenic poisoning in Antofagasta Commune for the 1968-71 period, were plotted against mean arsenic doses (mg/kg body weight/day) by age group. A dose-response curve was computed, being F = 83.19, d.f. = 1,7 and P less than 0.01 (slope). The correlation coefficient was + 0.9604.
Following a former suggestion (4) always to evaluate, the efficacy of procedures for Hygienic disinfection of hands in comparison with the results of a certain standard disinfection method, Ethanol, iso- and n-Propanol were tested in various concentrations and for various times of action on their usability in such a standard method. The disinfecting power was dependent upon (i) the alcohol (Ethanol less than iso-Propanol less than n-Propanol), (ii) the concentration (Ethanol: 60 less than 70 less than 80% ml/ml, iso-Propanol: 50 less than 60 less than 70, n-Propanol: 40 less than 50 less than 60 = 70) and (iii) the time of action (0,5 less than 1 less than 2 min). n-Propanol proved to be the fastest acting disinfectant. However, as standard disinfection method iso-Propanol (60% ml/ml) being used for 1 min has been proposed. Furthermore, the following results that have been obtained also in former investigations (8) could be confirmed: (i) there is no systematic difference between the release of test-bacteria from the fingertips of right and left hands of test-persons (ii). The efficacy of procedures for Hygienic disinfection of hands is besides other factors influenced by the testpersons. This factor may be eliminated by using the same testpersons for both, the disinfection procedure under investigation and the standard method. The results of both may, then, be related to each other and the efficacy of the former may be evaluated in comparison to the latter.
The discussion about the possible consequences from the agricultural use of composted sewage sludge; which contains considerable amounts of polycyclic, aromatic hydrocarbons (PAH), caused us to investigate the normal concentrations of these substances in soil from agricultural land. In 50 soil samples, mainly from various parts of the Federal Republic of Germany the following 6 PAH were determined: fluoranthene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, benzo(ghi)perylene, indeno(1.2.3-cd)pyrene. In 74% of the samples benzopyrene concentration was between 2 and 50 microgram/kg, and the sum of the 6 compounds between 50 and 500 microgram/kg. No smaller values were found, and higher concentrations in most cases could be connected to some source of pollution.
The chemical compounds which are discharged from the site at which old tires are incinerated in the open air roughly corresponded to those of waste water. In the smoke "mushroom" above the site of incineration, at a height of 31 to 40 metres, many types and large quantities of polycyclic aromatic and also cancerogenic hydrocarbons were found adsorbed on soot particles.
Simple aerobic treatment of swine waste did not increase the production of microorganismprotein (pure protein). Addition of available energy resulted in a small increase of pure protein: During continuous aerobic treatment 20 g pure protein were produced by 100 g starch, during discontinuous aerobic treatment 10 g pure protein by 100 g organic matter from molasses (mean values). Comparative feeding trials with 90% resp. 80% feed restricted finishing swine without and with added swine waste (continuous treated without supplements resp. discontinuous treated with addition of yeasts and molasses) had as results no improvement in body-weight-gain but a 12% resp. 17% deterioration in feed conversion with 13% less bodyfat formation. Weight gains of both groups with restricted feed (without and with added swine waste) was 22% less in comparison to full fed swine. Losses at slaughter of swine in the group with feed restriction and added swine waste were partly due to higher intestine contents higher than that of swine with feed restriction and without added swine waste. Higher weights of livers and kidneys in swine of the "waste group" counts for a possibly higher metabolism-stress.
Comparative analyses of the development rate of a slow Tumor (Methylcholanthrene) in mice were undertaken under conditions of a) an electrostatic field (Field strength 200 V/m, Residual sinus component 0.1%), b) a Faraday cage (Shielding effectivity on atmospheric electrical disturbances: 99%) and c) a laboratory, climatized with conventional methods. The tumor was initiated in each case following a 6-week acclimatisation period to the unaccustomed surroundings. Following this, we observed the appearance rates over a period of 8 months at 14-day intervals. Under customary laboratory conditions these were perceptibly higher than in the electrostatic field or in the Faraday cage. No difference was apparent between the two latter conditions. Any variations in the electrobioclimatological environment can lead to stress reactions resulting in familiar consequences to various defense mechanisms. This allows us to find an explanation for the results otherwise difficult to interpret; for both in the electrostatic field and under shielding from external electrical influences the neoplastic activity was obviously reduced in comparison to normally climatized laboratory conditions. We are continuing the experiments.
Virological examination of water of the Baltic Sea in the neighbourhood of a sewage outfall was done. By means of an apparatus for concentrating viruses in water, it was possible to detect enteroviruses in four of eleven samples, and in general in those moments, when conditions were fulfilled by a certain windway. The amount of viruses varied from 5 to 126 pfu in 10 liters, the ratio of virus to E. coli titer from 1:11 111 to 1:100 000. Factors influencing the decrease of virus titer in seawater were briefly discussed.
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