Biomedical subjects

J Schroettner

Publications and source records attributed to J Schroettner.

3 recordsLinked to original sources

PubMedDate not supplied

Electric current perception study challenges electric safety limits.

Although a key parameter for safety regulations, the electric current perception threshold is not sufficiently established yet. Present knowledge suffers from a lack of women's data, small numbers of data on investigation of men and investigated samples non-representative for the general population. With measurement at 708 adults aged between 16 and 60 years (349 men and 359 women) these deficiencies could be overcome. The results are important. They show that the perception variability among the general population is 100-fold higher than estimated so far and that the currently used estimate of the threshold is more than 10-fold too high. Besides this, it could be shown that there are an over-proportion of more sensitive women compared with men indicating the need for revision of the present assumptions on gender-specific differences in electrosensibility. The results show that the existing assumptions on safety limits and remaining safety factors need serious review. In any case, relaxation of safety requirements is not justified.

Adolescent↗

PubMedDate not supplied

Electric current perception of the general population including children and the elderly.

Although the 50 Hz electric current perception threshold is a key parameter for limiting electric touch currents in electrical technology and for limiting indirect effects of external electromagnetic fields, the data available mainly reflect men's perception ability; with only sparse data for women and almost none for children or the elderly. Measurements with 240 children aged 9 - 16 years, and 123 elderly people, allow this gap of knowledge to be filled. Taking into account the demographic age distribution, it was possible to generate a probability distribution representing the perception ability of the overall general population, and thus to provide a more established basis for deriving safety limits. The results show that the existing limit values for electric touch currents are considerably too high if compared with results derived from the new data with the same criteria. On the other hand, it appeared that children do not exhibit such a high sensitivity to electricity as assumed to date. Therefore, former rule-of-thumb estimates to account for higher sensitivities of children lie on the safe side. The presented assessment of the general population's electric current perception ability should stimulate a critical review of the existing regulations.

Adolescent↗

PubMedDate not supplied

Electric current perception of children: the role of age and gender.

Although it is widely accepted that children merit increased protection, little is known about the quantitative consequences of electric currents when setting safety limits. Measurements were performed on 240 children (117 girls and 123 boys) older than 9 years. It was found that the electrosensitivity of children was higher than that of adults, but did not exceed the overall span of adult electrosensitivity. Girls' results depend only weakly on age. Therefore, no major change should be expected below the age of 9. The electrosensitivity of boys increases with decreasing age; however, it finally approaches and merges with that of girls. The results imply that the factor by which the allowed touch current should be reduced for children depends on the perception probability level considered. The reduction factor of 2, as chosen in the past, would need revision either in regard to its value or to the related perception probability level. If related to the still existing rationale for safety limits the factor would need to be far higher.

Adolescent↗