Field surveys of earplugs fit- testing in China

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1 Wei Gong / Jiangsu Provincial CDC, China Yufei Liu / 3M China Xin Liu/ Jiangsu Provincial CDC, China NHCA Conference Feb. 2017, Texas Field surveys of earplugs fit- testing in China

2 Disclaimers The findings and conclusions in this presentation have not been formally disseminated by Jiangsu Provincial Center for Disease Control and Prevention, and should not be construed to represent any agency determination or policy. Mention of a company or product does not constitute endorsement by Jiangsu Provincial Center for Disease Control and Prevention.

3 3M E-A-Rfit Dual- Ear Validation System NIOSH HPD Well-Fit Personal Attenuation Rating (PAR) Noise attenuation headphones Laptop USB mouse

4 Test procedure Questionnaire Baseline / initial PAR failed No Noise Measure Completed Train & refit (intervention group) PAR failed again No New HPD & refit Yes

5 Part 1, Primary results with E-A-Rfit

Part 1, E-A-Rfit Information about surveyed factories Foam earplug Premolded earplug Model 3MT M 1110/1100 3M TM 1270 Labeled attenuation Factories and PAR criteria Relative ranking of HCP quality

6 Part 1, E-A-Rfit Information about surveyed factories Foam earplug Premolded earplug Model 3MT M 1110/1100 3M TM 1270 Labeled attenuation Factories and PAR criteria Relative ranking of HCP quality NRR: 29 db SNR: 37 db A: Machinery (15 db) B: Machinery (15 db) C: Textile (18 db) D: Power plant (10 db) A: No. 1, good follow-up action B: No. 2, average C: No. 3, poor HPD enforcement D: No.4, not good HPD enforcement NRR: 24 db SNR: 25 db E: Petrochemical (15 db) including 5 workshops E: No. 2, average

7 Part 1, E-A-Rfit General information about test subjects Service year Years of use of HPD Noise exposure duration per working day in hours <1 year 1 to 5 years 6 to 10 years >10 years 10 (10%) 281 (32%) 95 (11%) 504 (57%) <1 year 1 to 2 years 3 to 6 years >6 years 63 (9%) 116 (16%) 220 (30%) 328 (45%) < 1 h 1 to 4 hrs 5 to 8 hrs > 8 hrs 1 (0%) 224 (25%) 446 (50%) 214 (24%) Education level Grade school Junior high school High school Junior college or above 37 (4%) 170 (19%) 260 (29%) 432 (48%) Gender Male Female 723 (82%) 159 (18%)

Part 1, E-A-Rfit PARs - baseline vs. labeled attenuation value 35 Foam earplug n Mean (db) SD (db) 27 22 23 PAR - baseline 375 11 9.

8 Part 1, E-A-Rfit PARs - baseline vs. labeled attenuation value 35 Foam earplug n Mean (db) SD (db) PAR - baseline Premolded earplug n Mean (db) SD (db) PAR - baseline Foam Premolded PAR - baseline 2-dB corrected NRR 2-dB corrected SNR

9 Part 1, E-A-Rfit Effect of one-on-one training 35 Foam earplug Premolded earplug n PAR - Baseline PAR - after training Mean SD Mean SD (db) (db) (db) (db) Foam Premolded PAR - Baseline 2-dB corrected NRR PAR - after training 2-dB corrected SNR

10 PAR (db) Part 1, E-A-Rfit Effect of hearing conservation practice NOTE: Relative ranking of HCP quality is factory A > B > C PARs at baseline and after training, for initial visit, foam-earplug intervention group Factory A Factory B Factory C n=56 n=49 n=144 Baseline After training

11 PAR (db) Part 1, E-A-Rfit Effect of hearing conservation practice NOTE: Relative ranking of HCP quality is factory A > B > C Follow-up visit for foam-earplug intervention group (n=97) Factory A Factory B Factory C n=29 n=22 n=46 Baseline After training - 1st visit Follow up visit

12 Part 1, E-A-Rfit Easier to fit = easier to obtain higher protection? n Mean (db) SD (db) Premolded earplug initial in follow-up visit Foam earplug initial in follow-up visit P-Value = 0.1

13 PAR (db) Part 1, E-A-Rfit Easier to fit = easier to sustain the training effectiveness? 30 Follow-up visit for premolded earplug intervention group (n=74) Subjects Baseline After training Initial at 6-month follow up

14 Part 1, E-A-Rfit Is training conducted on representative group enough? n Mean (db) SD (db) P-value Baseline PAR Apr Baseline PAR Sep NOTE: Baseline PARs measured in Apr. and Sep. were from the same workshop.

15 Part 2, Primary results with Well-fit

Noise exposure levels (dba) Part 2, Well-Fit

Bilsom 304S 3M TM 1270 3M TM 1270 3M Yellow Neons

audiometry 3M TM 1100 HCP=3 No annual audiometry

16 Noise exposure levels (dba) Part 2, Well-Fit Information about surveyed factories Honeywell Bilsom 304S 3M TM M TM M Yellow Neons HCP=3 No annual audiometry HCP=3 No annual audiometry 3M TM 1100 HCP=3 No annual audiometry n=55 HCP=4 Annual audiometry Factory F Factory G Factory H Factory I Factories

17 Part 2, Well-Fit Demographics of workers Factory F Factory G Factory H Factory I Age Number Number Number Number < > Gender male female Total

18 PAR (db) Part 2, Well-Fit Effect of fit-testing PARs of baseline and after intervention on earplugs 40 Initial Fit-Test Final Fit-test Factory F, n=28 Factory G, n=25 Factory H, n=25 Factory I, n=55

19 Part 2, Well-Fit Effect of intervention Recommed Muff, 3% HPDs changed, 20% Passed first time, 69% Passed after intervention, 29% Training, 80%

20 Part 2, Well-Fit Do education levels play roles on PAR?

21 Part 2, Well-Fit Hearing thresholds (db) Well-fit = hearing screening tool? 100 Hearing threshold of subjects groups with and without hearing loss from audiometry Left ear Frequency (Hz) Right ear group with hearing loss group without hearing loss

22 Part 2, Well-Fit Hearing thresholds (db) Well-fit = hearing screening tool? 100 Hearing threshold of subjects groups with/without hearing loss from Well-Fit Occluded group with hearing loss Frequency (Hz) group without hearing loss Unoccluded

Absolute hearing thresholds (db Part 2, Well-Fit Interesting case- a worker with cotton ball 100 80 Occluded with cotton ball Occulded

23 Absolute hearing thresholds (db Part 2, Well-Fit Interesting case- a worker with cotton ball Occluded with cotton ball Occulded with 3m 1100 Unoccluded Frequency (Hz) Quote from Karplus Bonvallet - A Noise Survey of Manufacturing Industries

24 Absolute hearing thresholds (db) Part 2, Well-Fit Best results of hearing protection practice Task worker 1 worker 2 Prefabrication Operator Left Ear Frequency (Hz) Right Ear Worker Worker Age work years HPD used Cotton ball 3M TM 1100 Years of use of HPD 39 8

25 Conclusion Hearing protectors, even cotton balls are better than nothing; Individual fit-testing is the only way to definitely know whether a worker is adequately protected from noise; Individual training and intervention is necessary for workers exposures to high noise regardless of education levels; Follow-up testing is needed to figure out what is best period for redo the fit-testing; HPDs Well-fit could potentially be a hearing screening tool in the future.

26 Tips on field survey of HPDs fit-testing system Conduct noise measurement prior to field fit-testing; To reduce the test time, it is better to input the information of workers tested prior to field fit-testing; Well-Fit needs a quite test environment, such as a conference room or office; An ideal test team consists of 3-4 persons - one for questionnaires, at least one for fit-testing, and one for training failed workers, operating in different rooms to avoid creating background noise. Detailed feedback to HES managers is very important.

27 Acknowledgements NHCA William Murphy, PhD, NIOSH Elliott H. Berger, MS, 3M Xin Liu, PhD, JSCDC, China

28 Reference ANSI (1974). "Method for the Measurement of Real-Ear Protection of Hearing Protectors and Physical Attenuation of Earmuffs," Am. Natl. Stds. Inst., S , New York, NY. Gauger D, Berger EH (2004). A new hearing protector rating: the noise reduction statistic for use with A weighting (NRSA). Report for US Environmental Protection Agency. Approved by ANSI S12/WG11, E-A-R 04-01/HP, Indianapolis, IN. Karplus Bonvallet - A Noise Survey of Manufacturing Industries - Ind. Hyg. Quart ,1958 William J, Christa L. Themann, Taichi K. Murata. Field-Testing NIOSH HPD Well-Fit: Off-Shore Oil Rig Inspectors in Texas & Louisiana. EPHB Report No a

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