Effect of occupational exposure to extremely low frequency electromagnetic fields on level of thyroid hormones effective on fatigue

Q: How can I download an article?

To download an article from SID, first log in to the site, search for the article title, and click on the 'Download Article' option.

Q: How can I download an ISI article?

To download an ISI article on SID, enter the keyword or article title in the search bar, view the relevant results, click on the desired article, and select the 'Download Article' option.

Q: How can I access the SID database?

To access the SID database, visit SID.ir, create an account, and log in to access scientific resources.

Q: Is downloading articles from SID free?

Some articles on SID are available for free, while others require payment. Details are specified on the article's page.

HAJIZADEH ROOHALAH; MEHRI AHMAD; Razavi Seyed Mohammad Hassan; FARHANG DEHGHAN SOMAYEH; Faghihnia Torshizi Yoosef; MOTAMEDZADEH MAJID

Title

Effect of occupational exposure to extremely low frequency electromagnetic fields on level of thyroid hormones effective on fatigue

Author(s)

Keywords

Extremely low frequency electromagnetic fieldsQ1

Thyroid hormonesQ1

Arc weldingQ1

FatigueQ2

Abstract

Background and aims: ELF-EMFs (Extremely Low Frequency Magnetic Fields) are a type of non-ionizing radiation. ELF-EMFs are produced by the electromagnetic radiation of electrical equipment such as air power transmission lines or anything that electrical current passes through it. Several studies have shown that ELF fields can have direct adverse health consequences. It has been indicated that exposure to ELF-EMF could lead to genotoxic effects and DNA cancers damage, an increased risk of some cancers, depression, headaches, sleep disturbances, an increased risk of infertility and adverse pregnancy outcomes. Occupational exposure to ELF-EMF was mainly occurred in industrial processes such as welding which contains electronic elements. Welding is a common indispensable procedure in engineering works and over five million workers around the world are engaged in. Thyroid hormones have a role in fetal growth and development and regulation of the metabolism in adults and any thyroid hormone deficiency can lead to adverse mental health effects such as mood disorders like depression, drowsiness and Fatigue. Work forces’ Fatigue as an occupational hazard can be considered a significant problem in modern industry, since it can lead to loss in productivity, occurrence of human errors and occupational accident. The aim of this study was to assess exposure to Extremely low frequency electromagnetic fields (ELF-EMFs) and its effects on secretion of Thyroid hormones associated with symptoms of Fatigue on electric Arc welding workers. Methods: This case-control study was conducted to investigate the effects of extremely low frequency magnetic fields on level of Triiodothyronine hormone (T3), thyroxine hormone (T4) and thyroid stimulating hormone (TSH) secretion in welders (who are occupationally exposed to ELF-EMFs) and non-welders (as an unexposed group) in a mold making company. Through referring employee's medical records and consultation with occupational medicine specialist, people with known mental and physical illness were excluded from the study. Then 35 arc welders having more than one year of experience were simple randomly selected as exposed group and 35 non-welders were simple randomly selected as unexposed one. The age difference between the two groups should not be more than a year old. A signed informed consent had been obtained from all participants. Ethical approval was granted by the Research Ethics Committee of Qom University of Medical Sciences. In order to determine the level of Thyroid hormones, blood samples were taken for both groups at the same time before starting working. Then, the samples were transported to the laboratory and stored at temperature less than-20º C. The enzyme-linked immunosorbent assay (ELISA) test was used to measure the level of T3 and T4 in plasma, and electrochemiluminescence immunoassay (ECLIA) method was used to measure plasma TSH. Extremely low frequency magnetic fields were measured using an electromagnetic field meter. Measurements were carried out in the area of the hand, neck, trunk and head and also at the intervals of 0. 5, 1 and 2 meters of welding equipment, according to NIOSH (National Institute of Occupational Safety and Health) guideline. Fatigue assessment was done using Samn-Perelli seven-point Fatigue scale. This questionnaire is a subjective measure tool for assessing the own level of Fatigue, where 1 = fully alert, wide awake and 7 = completely exhausted, unable to function effectively. This is sensitive to Fatigue outside laboratory conditions and it can be easily administered in the field. Analysis was performed using SPSS v. 20 software. Analytical statistics including t-test, chi-squared test, Analysis of variance (ANOVA) were used to compare the results between the groups. Also, the Pearson correlation coefficient is used to measure the strength of a linear association between variables. Normality of the study data was tested with a 1-sample Kolmogorov-Smirnov test. The significance level was set to 0. 05. Results: Demographic analysis showed that the mean age in exposed and unexposed groups were 38 (± 6. 03) and 39 (± 6. 02) years, respectively. The mean body mass index (BMI) and duration of employment of the exposed and unexposed participants were 25. 76 (± 6. 31) and 26. 04 (± 5. 98) Kg/m2 and 13. 02 (± 5. 20) and 13. 04 (± 4. 11) years, respectively. There was no statistically significant difference between two groups in case of all studied demographic variables (p> 0. 05). The result of Kolmogorov-Smirnov (KS) test showed that all of the studied variables follow a normal distribution (p> 0. 05). The highest exposure level was found in the hand area (2683. 8 mG) and the lowest one was obtained at a distance of 2 meters from the Welding equipment (122. 2 mG). The mean exposure to ELF in exposed group, in all measurement areas, had a significant difference with the unexposed one (p<0. 0001). According to the threshold limit values (TLV) of American Conference of Governmental Industrial Hygienists (ACGIH), occupational exposure limit is between 0. 2 to 60 mT (2, 000 to 600, 000 mG) which can be changed at different frequencies. Based on the obtained results, overall exposure to extremely low frequency magnetic field is less than the recommended values by ACGIH in all participants. The mean levels of T4 and TSH were significantly lower in the exposed group than non-welders (p<0. 05). However, the mean level of T3 in the arc welders was lower than the unexposed group, but this difference was not statistically significant (p<0. 05). Thyroid hormone levels in 23 subjects (65%) of welders fell outside of the normal range at least in case of one the hormones; while thyroid hormone levels only for 15 subjects (42%) of non-welders wasn't in the normal range at least in case of one the hormones. There is no significant correlation between demographic parameters such as age, BMI, and duration of employment with the T3, T4, TSH hormones in exposed and unexposed groups (p>0. 05). The percentage of individual Fatigue in welders had a significant difference with non-welders (p<0. 01). There is a weak positive relationship between ELF-MF exposure value and level of Thyroid hormones (p>0. 05) and also, the score of Fatigue significantly increases by reducing T3 and T4 hormones (p<0. 05). Conclusion: As a result of this study, the blood level of thyroid hormone in the exposed group was less than the unexposed one, so that the mean difference for T4 and TSH hormones were statistically significant. Moreover, the prevalence of the hormone disruption among welders was higher than the unexposed group. According our findings, the Fatigue is more common in welders than non-welders. The results showed that welding can be considered one of ELF field sources. Consistent long-term exposure to ELF-EMFs from the welding process may result in abnormalities in Thyroid hormones T4 and TSH, and may increase Fatigue in welders. Regarding welding processes being widely used; preventive measures to ELF exposure should be adopted. Since there is no practical and cost-effective method for protection against extremely low frequency magnetic fields, it should be better to limit exposure time to these fields. In conclusion, Exposure to ELF-EMFs may disrupt the thyroid hormone secretion such as T4 and TSH levels and may increase the Fatigue level. This study is only a starting point and many issues need to be addressed for drawing definite conclusions.

No record.

APA: Copy

HAJIZADEH, ROOHALAH, MEHRI, AHMAD, Razavi, Seyed Mohammad Hassan, FARHANG DEHGHAN, SOMAYEH, Faghihnia Torshizi, Yoosef, & MOTAMEDZADEH, MAJID. (2019). Effect of occupational exposure to extremely low frequency electromagnetic fields on level of thyroid hormones effective on fatigue. IRAN OCCUPATIONAL HEALTH JOURNAL, 16(1 ), 1-12. SID. https://sid.ir/paper/388438/en

Vancouver: Copy

HAJIZADEH ROOHALAH, MEHRI AHMAD, Razavi Seyed Mohammad Hassan, FARHANG DEHGHAN SOMAYEH, Faghihnia Torshizi Yoosef, MOTAMEDZADEH MAJID. Effect of occupational exposure to extremely low frequency electromagnetic fields on level of thyroid hormones effective on fatigue. IRAN OCCUPATIONAL HEALTH JOURNAL[Internet]. 2019;16(1 ):1-12. Available from: https://sid.ir/paper/388438/en

IEEE: Copy

ROOHALAH HAJIZADEH, AHMAD MEHRI, Seyed Mohammad Hassan Razavi, SOMAYEH FARHANG DEHGHAN, Yoosef Faghihnia Torshizi, and MAJID MOTAMEDZADEH, “Effect of occupational exposure to extremely low frequency electromagnetic fields on level of thyroid hormones effective on fatigue,” IRAN OCCUPATIONAL HEALTH JOURNAL, vol. 16, no. 1 , pp. 1–12, 2019, [Online]. Available: https://sid.ir/paper/388438/en

No record.

Scientific Information Database

ISSN: 2588-4824

Journal Paper

Effect of occupational exposure to extremely low frequency electromagnetic fields on level of thyroid hormones effective on fatigue