C. M. U-Dominic, A.C.C. Ezeabasili & B.U. Okoro,
Noise pollution has always been a prevalent case in industrial environment, yet there has never been a cohesive assertion on the actual effect of these noise exposures on the blood pressure. Many occupational studies have allied exposure to noise in working environment to a number of physiological and psychological responses like secretion of adrenaline and cortisol needed to adjust the body function but in-return may result to an increase in blood pressure. On the contrary, some researchers have emphatically disagreed with the findings by pointing-out that different individuals are likely to exhibit different noise excitations. This research was to investigate whether there is noise pollution in sawmills and also to examine if there is any significant blood pressure changes as a result of the noise pollution. The research was carried out in phases. In the first phase of the study, a sound level meter was used to determine the ambient noise levels in the sawmills. These measured noise levels were used to calculate workers exposure dosage. In the subsequent phase of the study, a structured health and life style questionnaire was used as exclusion criteria for the selection of the eventual subjects that was tested with automatic sphygmomanometer for blood pressure difference. The research population comprises a population of male and female(n=101) in the sawmill environment, who had been exposed to high level of noise from one year and above and whose activities are within the measured noise level distance. The blood pressure and pulse pressure was measured at regular two-minute intervals before, and after prolonged period of exposure to high (fluctuating) noise level. Result was analyzed by SPSS-17 package using student t-test. The subjects selected for control group were six volunteer students (male), aged 25-32 years and were exposed to high level of (fluctuating) noise, and later exposed to experimental conditions, without production of noise. The result of the study have established that noise pollution was prevalent in these sawmills, and has a significant effects on the blood pressure. However, these effects as regards to increase or decrease depends on some other un-captured factors since individual noise appraisal and societal appreciation of the activities generating the noise have also a notable effect on whether the effect would be tending towards a decrease or increase. In conclusion, the noise exposure dosage of these sawmill workers exceeds the permissible exposure limit as prescribed by the occupational safety and health administration. In addition, prolonged exposure to high (fluctuating) noise levels may be a possible influence on the blood pressure changes.