Medical/biological study (observational study)

Investigating the effects of vitamins E and C on oxidative stress and hematological parameters among power plant workers: A double-blind randomized controlled clinical trial med./bio.

By: Hosseinabadi MB, Khanjani N, Norouzi P, Mirzaii M, Biganeh J, Nazarkhani F

Published in: Toxicol Ind Health 2020; 36 (2): 99-109

Aim of study (acc. to author)

The effects of an administration of vitamin C and vitamin E on oxidative stress and hematological parameters in power plant workers should be investigated.

Background/further details

A total of 81 employees from different parts of a power plant were divided randomly into the following groups: 1) vitamin E administration (400 units/day) (n=21), 2) vitamin C administration (1000 mg/day) (n=20), 3) vitamin E + C administration (n=21), 4) control group (sham administration) (n=19). All participants received their administrations for 90 days, before and afterwards blood samples were collected.

Endpoint

oxidative stress in blood and hematological parameters

Exposure

- co-exposure

Exposure	Parameters
Exposure 1: LF (< 10 MHz) Exposure duration: at least 2 years job experience before beginning of intervention, 90 days in a full time job during intervention	magnetic flux density: 6.49 µT minimum magnetic flux density: 39.25 µT maximum electric field strength: 4.89 V/m minimum electric field strength: 44.82 V/m maximum

Exposure 1

Main characteristics

Frequency	LF (< 10 MHz)
Type	electric field magnetic field
Exposure duration	at least 2 years job experience before beginning of intervention, 90 days in a full time job during intervention

Exposure setup

Exposure source	different work places in a power plant

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	6.49 µT	minimum	measured and calculated	-	-
magnetic flux density	39.25 µT	maximum	measured and calculated	-	-
electric field strength	4.89 V/m	minimum	measured and calculated	-	-
electric field strength	44.82 V/m	maximum	measured and calculated	-	-

Additional parameter details

levels of exposure to electric and magnetic fields were not significantly different between the groups

Measurement and calculation details

participants determined their working and resting stations and the amount of time that they spent on each station during a normal work shift; the exposure to electric and magnetic fields was calculated separately as the 8 h time-weighted average

Reference articles

Cam ST et al. (2011): Occupational exposure to magnetic fields from transformer stations and electric enclosures in Turkey

Exposed system:

human

Methods Endpoint/measurement parameters/methodology

oxidative stress in blood (enzyme activities of antioxidative enzymes superoxide dismutase, catalase and total antioxidant capacity, amount of malondialdehyde as a lipid peroxidation marker; commercial kits and ELISA) and hematological parameters (white blood cell count, lymphocyte count, red blood cell count, hemoglobin, hematocrit, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration, platelet and mean platelet volume; method not mentioned); subjective symptoms (questionnaire)

Investigated system:

isolated bio./chem. substance
blood samples

Time of investigation:

before exposure
after exposure

Main outcome of study (acc. to author)

A significant increase in the levels of superoxide dismutase and catalase enzyme activities and in the total antioxidative capacity was found in all vitamin-treated groups (groups 1-3) as well as a significant decrease in lipid peroxidation in the vitamin E (group 1) and C group (group 2) after the intervention compared to before. In all vitamin-treated groups, the number of red blood cells, hematocrit, the level of mean corpuscular hemoglobin and the mean corpuscular hemoglobin concentration were significantly increased after the intervention compared to before. In the control group, no significant changes between before and the interention were found. (Remark EMF-Portal: results for subjective symptoms are not mentioned.)
The authors conclude that administration of vitamin C and vitamin E might attenuate oxidative stress and improve hematological parameters in power plant workers.

Study character:

medical/biological study
observational study
pilot/exploratory/preliminary study
intervention study
double-blind study

Study funded by

Shahroud University of Medical Sciences, Iran

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