Correlation between Screening estimation and noise measurement in Small Plants in Varamin city

In Iran country، small enterprise with less than 10 workers comprise about %90 of all industries and 80% of working population. Noise، higher than the permissible level is among the hazardous agents، workers in these plants facing with. The aim of this study was to investigate the correlation between screening estimation and noise measurement in small plants.

This cross-sectional study was conducted in 51 plants with less than 5 workers. Noise screening was done using screening from. Next، noise level was measured in all the plants by TES-1358 sound level meter and regular grid method. Data were analyzed using chi-square test and linear regression in SPSS version 16

The mean (SD) scores of sound pressure level and screening form were 86. 5 dBA (4. 5) and 64. 2 (9. 4) in 51 understudy plants، respectively. According to the results of sound measurement، sound level in 34 plants (66. 6%) exceeded the permissible level and in 17 plants (33. 33%) was below the limit. The results of screening forms showed that 47 plants (92. 16%) had permissible level of noise while noise in 4 (7. 84%) was not in permissible level. Chi square test revealed no significant relationship between the results of the two methods، based on the permissible and impermissible limits (p-Value=0. 288). Furthermore، according to the regression analysis، R2 was obtained 0. 357.

No correlation was shown between the results of the two methods used. Thus، it is recommended to change the parameters used in the noise screening form for small plants، with less than 5 workers.