The Effects of Sound Pollution on the Serum Levels of Corticosterone and Other Hematological Parameters in Male Rats

Sound pollution is one of the main causes of stress that could lead to several physiological and mental changes in humans. This study aimed to investigate the effects of sound pollution on the serum levels of corticosterone and other hematological parameters in male rats. In this experimental study, 60 male Wistar rats were randomly divided into two groups of short-term experiment (one-day exposure) and long-term experiment (30-day exposure). Each group consisted of one control group and three experimental groups with 4, 8 and 12 hours of exposure to noise pollution. According to a pre-designated schedule, the animals were exposed to 100 dB sound pressure, and changes in the serum levels of corticosterone and hematological parameters were recorded. In this study, serum levels of corticosterone increased in the long-term exposure group (8 hours: 5.36±3.19 ng/dl, 12 hours: 4.88±1.76 ng/dl) compared to the control group (1.08±0.53 ng/dl) (p<0.01 and p<0.001, respectively). Number of red blood cells also increased in the long-term exposure group (8 hours: 7.71±0.33 mm3, 12 hours: 8.22±0.69 mm3) compared to the control group (6.24±0.16 mm3) (p<0.05 and p<0.01, respectively). In addition, there was an increase in hemoglobin concentration in the long-term exposure group (8 hours: 16.66±0.68 gr/dl, 12 hours: 16.60±0.81gr/dl) compared to the control group (14.15±0.66 gr/dl) (p<0.05). Moreover, there was a significant increase in the hematocrit in the two groups of 8 hours (40.57±3.28) and 12 hours (40.66±1.76) of long-term exposure compared to the control group (35.69±3.13) (p<0.05). According to the results of this study, long-term exposure to noise pollution could increase the number of red blood cells and other hematological parameters by raising the serum levels of corticosterone.