Abstract
Objective: To observe the electrocardiogram (ECG) changes in the population living in the region with coal-burning-borne endemic fluorosis (EF for short) after comprehensive controls. Methods: People living in a region with coal-burning-borne EF in Bijie City of Guizhou Province were selected and then divided into 4 groups according to the severity of fluorosis and the duration of the comprehensive controls in 2011: group of mild fluorosis + short duration (52 subjects from Shadi Village), group of mild fluorosis + long duration (58 subjects from Xiaba Village), group of serious fluorosis + short duration (52 subjects from Maoliping Village), and group of serious fluorosis + long duration (60 subjects from Zhongtun Village); persons living in a fluorosis-free region (57 subjects from Shawenxin Village) of Guiyang City were chosen as controls. A synchronous ECG device was used to observe ECGs of the population. Results: In contrast with fluorosis-free controls [47.4% (27/57)], the rate of abnormal ECG for the group of serious fluorosis + short duration [71.2% (37/52)] and the group of serious fluorosis + long duration [66.7% (40/60)] was significantly increased (?2 values were 6.346 and 4.448 respectively; P < 0.05 for both groups) while the rate of abnormal ECG for the group of mild fluorosis + short duration [61.5% (32/52)] and the group of mild fluorosis + long duration [56.9% (33/58)] did not differ significantly (?2 values were 2.199 and 1.046 respectively; P > 0.05 for both groups); the difference regarding abnormal ECG rate in populations in groups of the same fluorosis severity and different durations was of no statistical significance (?2 values were 0.244 and 0.261 respectively for groups of mild fluorosis and groups of serious fluorosis; P > 0.05 for all groups). Conclusions: The population living in the region with serious EF had a higher rate of abnormal ECG, and the rate of abnormal ECG did not drop significantly after a definite duration of comprehensive controls.