Chronic Toxicity/Oncogenicity Evaluation of 60 Hz (Power Frequency) Magnetic Fields in F344/N Rats
| Autor: | Gary A. Boorman, David L. McCormick, John C. Findlay, Robert M. Kovatch, James R. Hailey, Robert C. Sills, Tim R. Johnson, Joseph K. Haseman, James R. Gauger |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
Adenoma
Male medicine.medical_specialty Neoplasms Radiation-Induced 040301 veterinary sciences Mammary Neoplasms Animal 030209 endocrinology & metabolism Biology Toxicology Pathology and Forensic Medicine 0403 veterinary science 03 medical and health sciences Electromagnetic Fields Sex Factors 0302 clinical medicine Internal medicine medicine Animals Thyroid Neoplasms Molecular Biology Survival rate Chronic toxicity Carcinogen Leukemia Radiation-Induced Body Weight Thyroid Cancer 04 agricultural and veterinary sciences Cell Biology medicine.disease Rats Inbred F344 Rats Survival Rate Radiation Injuries Experimental Leukemia medicine.anatomical_structure Endocrinology Evaluation Studies as Topic Fibroadenoma Carcinoma Medullary Toxicity Female Whole-Body Irradiation |
| Zdroj: | Toxicologic Pathology. 27:267-278 |
| ISSN: | 1533-1601 0192-6233 |
| Popis: | A 2-yr whole-body exposure study was conducted to evaluate the chronic toxicity and possible oncogenicity of 60 Hz (power frequency) magnetic fields in rats. Groups of 100 male and 100 female F344/N rats were exposed continuously to pure, linearly polarized, transient-free 60 Hz magnetic fields at flux densities of 0 Gauss (G) (sham control), 20 milligauss (mG), 2 G, and 10 G; an additional group of 100 male and 100 female F344/N rats received intermittent (1 hr on/1 hr off) exposure to 10 G fields. Mortality patterns, body weight gains throughout the study, and the total incidence and number of malignant and benign tumors in all groups exposed to magnetic fields were similar to those found in sex-matched sham controls. Statistically significant increases in the combined incidence of C-cell adenomas and carcinomas of the thyroid were seen in male rats chronically exposed to 20 mG and 2 G magnetic fields. These increases were not seen in male rats exposed continuously or intermittently to 10 G fields or in female rats at any magnetic field exposure level. No increases in the incidence of neoplasms, which have been identified in epidemiology studies as possible targets of magnetic field action (leukemia, breast cancer, and brain cancer), were found in any group exposed to magnetic fields. There was a decrease in leukemia in male rats exposed to 10 G intermittent fields. The occurrence of C-cell tumors at the 2 lower field intensities in male rats is interpreted as equivocal evidence of carcinogenicity; data from female rats provides no evidence of carcinogenicity in that sex. These data, when considered as a whole, are interpreted as indicating that chronic exposure to pure linearly polarized 60 Hz magnetic fields has little or no effect on cancer development in the F344/N rat. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|