Health Effects On Workers Exposed To Occupational Noise Among A Chemical Plant

Objective:To study the effects of steady noise has on the health of workers who work in a workshop of one chemical company.Methods:Select 175 workers who exposed to noise occupationally as "Exposed Group" while 152 non-noise exposure workers as "Control Group". Gender:Male. Age:from 22 to 30. 3-6 years noise exposure history. Conduct yearly working area noise evaluation and personal noise exposure level evaluation. Deliver annual occupational health exam to both exposed group and control group. The occupational health exam items include:audiometry test (low frequency/high frequency), cardiovascular system (BP/HR/ECG), blood routine (Hb/WBC/RBC/PLT), blood biochemistry indexes (GLU/TG). Calculate CNE[dB (A) year]. Establish the database in excel, and conduct data analysis with SPSS17.0 and Logistic to analyze the effects of steady noise has on the health of workers.Result:1. The type of noise in the targeted workshop is industrial is "steady noise". Since the operation process didn’t change during Year 2007 to Year 2012, the monitored noise exposure data are among a steady range. For the Exposed Group, the area noise data is from 84.8 dBA to 94.0dBA, while the personal noise exposure level is 84.5 dBA-91.6dBA; for the Control Group, the area noise data is from 70.0 dBA -80.0dBA, while the personal noise exposure level is from 74.0dBA-80.0dBA.The CNE data is different with different working years. CNE is (92.82±3.55) [dB (A). Year] with 3 working years; CNE is (94.07±3.55) [dB (A). Year] with 4working years; CNE is (95.04±3.56) [dB (A). Year] with 5 working years, and the CNE result is (95.83±3.55) [dB (A). Year] with 6 working years.2. Auditory System:80 workers (45.7%) of exposed group tested shows hearing loss, among which 12 workers (6.8%) are low frequency hearing loss,74 workers(42.3%) are high frequency hearing loss.24 workers (15.8%) of control group tested shows high frequency hearing loss. The differences were statistically significant (P<0.01). When analyzing the high-frequency hearing loss group via "working years", the hearing loss were statistically significant for 1 to 4 working years, but not statistically significant for 5-6 working years. The result was opposite for low frequency hearing loss which were not statistically significant for 1 to 4 working years, but statistically significant for 5-6 working years. The result shows the more years workers exposed to noise occupationally, the CNE is higher, the hearing loss rate is higher; high-frequency hearing loss come up earlier than low-frequency hearing loss.3. Cardiovascular system:67 workers (38.3%) of exposed group tested shows abnormal BP,10 workers (5.7%) shows abnormal HR,27 workers (15.4%) shows abnormal ECG. The BP differences were statistically significant (P<0.01), however, the result for HR and ECG were not statistically significant (P>0.05) in both groups.4. Blood Routine:24 workers (13.7%) of exposed group tested shows abnormal Hb while> 28workers (18.4%) in control group; 81workers (46.3%) of exposed group tested shows abnormal WBC while 37workers (24.3%) in control group; 73 workers (41.7%) of exposed group tested shows abnormal RBC while 48 workers (31.6%) in control group; 11 workers (6.3%) of exposed group tested shows abnormal PLT while no worker in control group. The WBC and PLT differences were statistically significant, however, the result for RBC and Hb were not statistically significant (P>0.05) in both groups.5. Endocrine system (GLU/TG):8 workers (4.6%) of exposed group tested shows abnormal GLU while 11 workers (7.2%) in control group; 56 workers (32%) of exposed group tested shows abnormal TG while 43 workers (28.2%) in control group; The result for GLU and TG were not statistically significant (P>0.05) in both groups.Conclusions:Exposure to occupational steady noise has different effect on different body systemsExposure to occupational noise can result in hearing loss, and the high frequency hearing loss is earlier than low frequency hearing loss in term of time; it can cause abnormal BP and is positive correlation with working years; the result shows abnormal WBC and PLT, however, this can’t be a proof of the positive relationship between noise and routine blood because there is no direct connection between noise’s impact on peripheral blood, no previous research result for this either, it is more likely to be result of unknown personal daily habits; it has no impact on RBC, HR, GLU and TG. The workers can be protected by decreasing the occupational exposure noise especially in hearing function.