Study On The Influences Of Power Frequency Electromagnetic Field On Pupil’s Health Indicators

Objective： International agency for research on cancer(IARC) classificates powerfrequency electromagnetic field in human suspected carcinogen (2B). The backgroundvalues of ELF are relatively low in our living environment, which arouse controversyabout its influences on children’s immune systems and oxidative stress. This studyaims to investigate the influence of power frequency electromagnetic field on primaryschool students’ immune system and oxidative stress function, so as to provide basisfor further research about the power frequency electromagnetic field effects on humanhealth.Methods： In the school near500kv power transmission line,456primary studentsfrom4to6grade were randomly selected as exposed group. While at the other schoolwhich is10kilometers away from the power line and with no typical radiation source,another272students were randomly selected as control group. Measure and comparethe intensity of the electromagnetic field between the two groups. Carry on physicaland blood routine examination for the students. Including the lymphocyte count, thelevels of serum IgG, IgM, the contents of lysozyme, superoxide dismutase (SOD),malondialdehyde (MDA) level and total antioxidant (T-AOC) in their serum.Blood routine index were WBC,RBC,HGB and PLT.Results： The electric field intensity on21monitoring points of the exposed schoolranges from522to3930mV/m, while it ranges from16to2919mV/m in the controlgroup. The magnetic field intensity of the exposed school were from171.5nT to357.8nT, while it was from9.95to72.08mV/m in the control. All of those measured valuesare lower than the international radiation protection association rules limiting values4kV/m for power frequency electric field and100μT for magnetic field. The powerfrequency electromagnetic field intensity of exposure group was higher than the control group, the difference was statistically significant (P <0.001). Immunologicalindicators examination showed that the IgG, IgM levels of the exposed pupils werelower than the control.while lymphocyte count and saliva lysozyme content have nostatistical significance between the two groups (P>0.05). Oxidative stress indexesexamination shows that total antioxidative capacity for the exposed group issignificantly higher than control group (P <0.05), but there is no significant differencefor serum SOD and MDA content between the two groups (P>0.05).Blood routine index results showed that HGB of the exposed pupils was significantlyhigher than the control (P <0.05).Conclusion：The number of lymphocytes was increased and the levels of IgG andIgM were significantly reduced in primary school students exposed to power frequencyelectromagnetic field. Which indicated that the power frequency electromagnetic fieldscan suppress the immune function on primary school students. On the other hand,power frequency electromagnetic field increased total antioxidative capacity inexposed pupils,serum. However, it has no significant influence on SOD and MDAcontent in pupils,serum. This exposure also led a higher HGB ofblood routine index.This cross-sectional survey can only provide possible clues foretiology hypothesis. To carry on further study, we still need to strengthen thepopulation epidemiological research and get combination with cells, animalexperiments.