Extremely low-frequency magnetic fields and cancers / 中国组织工程研究

ABSTRACT

OBJECTIVE: All the people in modern world are exposed to the industrial frequency magnetism (extremeiy low-frequency magnetic fields, ELFMF). There are important academic and practical significance to understand the influence of ELFMF on human diseases.DATA SOURCES A computer-based online search was conducted in HighWire database for English literatures about the relation between ELFMF and human cancers from January 1991 to March 2006 by using the key words of "extremely low frequency magnetic fields, cancer".STUDY SELECTION All the collected literatures were screened. Inclusion criteria ① To browse the abstracts of the literatures to examine primitively, and select the articles experimented with the cytological, molecular biological and epidemiological methods. ② Choosing the separate articles by studying with different animals but having got the same results.③ Comparing and analyzing the original and reviewed articles about the relations between ELFMF and cancers.DATA EXTRACTION A total 90 original and 4 reviewed literatures about ELFMF and cancers were collected and 29 and 4 papers were accordance with the criteria, respectively. In the 47 eliminated articles, 32 of them were unrelated or repetitive to our topic, 5 of them were published earlier or the conclusions were ambiguous, and other 10 of them used only the epidemiological methods.DATA SYNTHESIS: ① For a long time, the question whether 50/60 Hz ELFMF has the carcinogenic effects has been disputed in epidemiology and cytology. ② Majority statistical results in epidemiology showed that the crowds exposed to ELFMF for long or frequent time had an higher ratios suffering cancers than the normal, thereinto, the dangerousness such as leucocythemia, brain cancer and breast cancer is especially high. ③ However, the observation in cytology indicated that the normal cultural cells exposed to ELFMF had not increased the cell divisions or appeared cancer signals, and even in some reports, ELFMF may accelerate apoptosis, and reduced the possibility of cancerization. ④ Although ELFMF may not produce cancerization to normal cells, it may act as an promoter or co-promoter of cancer-prone cells, to accelerate the cancerization and exacerbation course of those cells. ⑤ The effect is related to influencing various links of signal transduction, changing translation of gene, changing activities of some enzymes and increasing production of free radicals.CONCLUSION: Although ELFMF may not produce cancerization to normal cells, it may act as an promoter or co-promoter of cancer-prone cells, to accelerate the cancerization and exacerbation course of those cells.