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Biomedical subjects

H Overath

Publications and source records attributed to H Overath.

6 recordsLinked to original sources
PubMed1999

[TEIS--a system for public health offices for assessing, presenting, evaluating and communicating data on the quality of drinking water].

Monitoring the quality of drinking water is a cardinal task of German Public Health Offices and of the relevant Ministries of Health of the German Federal states ("Länder"). Today this can be tackled on a large scale and economically only with computer assistance. A system has been developed in North Rhine Westphalia on behalf of the Ministry of Health, for data assessment and communication which is suitable for practical work and user friendly. It aims at supporting the Public Health Offices in their daily work and at improving and simplifying the monitoring of drinking water supply systems and of drinking water quality control.

Communication↗
PubMed1989

[The removability of pesticides during the production of dialysis water (2)].

In many cases it can be demonstrated that the amount of plant protectives and plant treatments (pesticides) in drinking-water exceeds the permitted levels of the drinking-water decree which will be effective on October 1st, 1989. These components are in parts toxicologically important. Therefore, an examination was made on how far pesticides are removed during the conventional purification of dialysis water, but especially during the reverse osmosis. Retention rates of a reverse osmosis plant for 14 different pesticides were discovered which were used in different concentrations and compositions. In part 2 of this contribution the results of the investigation are presented. The figures demonstrate that almost all of the examined components were retained with an effectiveness of 92-98%. The elimination efficiency did not depend on the basic concentration of the pesticides. After an initial phase of 50 h duration, the permeat concentration reached a constant value which did not alter even after more than 700 h.

Dialysis↗
PubMed1989

[Reducing chloramines in drinking water].

Monochloramine is produced when drinking water containing ammonium is chlorinated. It has long been known that activated charcoal destroys monochloramine. However, exact data for the dimensioning of a dechloramination plant were lacking. Four different commercially available activated charcoals were characterized (size of particle, iodine number) and examined for their effectiveness in removing monochloramines. The degradation of monochloramine by active charcoal is based on a chemical reaction of first order between carbon and monochloramine. The types of activated charcoal considerably differ in terms of reaction velocity, due in part to the mean granular size. The final concentration of the monochloramines is influenced only by their length of stay in the activated carbon filter, the temperature and the inflow concentration. A mathematical model describes the dependence of the degradation rate of the monochloramines on various factors. With its aid a nomogram can be established with which, simply and quickly, the activated charcoal needed in a concrete case can be determined.

Charcoal↗
PubMed1989

[Ability to remove pesticides in the production of dialysis water (1)].

In many cases it can be demonstrated that the amount of plant protective and plant treatment substances (pesticides) in drinking water exceeds the permitted levels of the drinking water ordinance which will come into effect on October 1st, 1989. Since some of these components are of toxicological relevance, an investigation was done on how far pesticides are removed during conventional purification of dialysis water, and especially during reverse osmosis. The retention rates of a reverse osmosis plant for 14 different pesticides applied in different concentrations and compositions were determined. Almost all of the substances examined were retained with an effectiveness of 92-98%. The elimination efficiency did not depend on the initial concentration of the pesticides. After an initial phase of 50 h duration, the concentration in the treated water reached a constant value which no longer changed even after more than 700 h. In part 1 of this contribution at first the fundamentals of dyalisis water purification are reviewed and a selection of the pesticides to be investigated is carried out. In addition experimental set up and procedure are described.

Filtration↗
PubMedDate not supplied

[Some comments on the 2nd European drinking water guideline].

It took 18 years before issuing a revised version of the first EU Drinking Water Guideline. As is well known, it did not receive unanimous acclaim neither by the water supply nor by the public health authorities. The second guideline has now been released and can be welcomed as a quite logically constructed and consistent version in comparison to its predecessor. Borderline values are stated only for those microbiological and chemical ingredients of water that are relevant to health. These borderline values must be considered as minimum deadlines and may not be raised by a member country although their severity may be increased. Basing on recent toxicological findings some of the borderline values have been raised or lowered compared to the previous version. On the other hand, however, the aesthetic aspects of drinking water have been neglected. In this respect we may look forward with interest as to how German legislation will implement the new guideline. This will have to be done at the latest by 2000 A.D. end.

Europe↗