Cleanroom air is extremely dry, as it is maintained within 1 % of relative humidity. Few studies have assessed the dermatologic life quality of workers in ultralow-humidity environments. Therefore, we aimed to evaluate the dermatologic life quality of cleanroom workers using the Skindex-29, compared to those of non-cleanroom workers.

Study participants were 501 cleanroom workers and 157 non-cleanroom workers from a secondary battery factory, who underwent an employee health examination at a single university hospital from September 2014 to September 2015. Results of the self-administered Skindex-29, and McMonnies questionnaire were analyzed. Other information and disease history were also collected during physician's medical examination. Descriptive and multivariate logistic regression analysis were performed.

The Skindex-29 score was significantly higher in cleanroom workers than in non-cleanroom workers for all domains, Symptom (16.0 ± 15.9 vs. 6.3 ± 10.2, p < 0.001), Emotion (11.3 ± 17.4 vs. 2.5 ± 7.4, p < 0.001), Function (5.2 ± 11.1 vs. 1.6 ± 4.0, p < 0.001), and Overall (10.8 ± 13.4 vs. 3.5 ± 6.2, p < 0.001). The Skindex-29 score of cleanroom workers was similar to that of patients with skin diseases such as psoriasis, other dermatitis, corns, alopecia etc. Among the cleanroom workers, 37 workers had one or more skin diseases.

Among the risk factors, ‘working at cleanroom’, ‘possessing skin disease’ and ‘McMonnies score’ had significant strong correlations with Skindex-29 score, meanwhile age, sex, smoking, drinking and exercise had weak correlations with it.

‘Working at cleanroom’ and ‘possessing skin disease’ had highest odds ratios with overall 14.0 (C.I.: 5.9–33.1) and 13.4 (C.I.: 4.5–29.2), and the lowest odds ratios with function domain 3.5(C.I.: 1.7–7.1) and 4.5(C.I.: 2.1–9.5), respectively. The McMonnies score had the highest odds ratio with overall, 6.9(C.I.: 4.5–10.8) and lowest odd ratio with emotion domain 4.2 (C.I.: 2.7–6.4).

Dermatologic life quality among cleanroom workers in the secondary battery factory is shown to be lower than that among non-cleanroom workers in this study. The study suggests that the Skindex-29 may provide helpful information on the dermatologic life quality of cleanroom workers. Therefore, regarding evaluation of dermatologic life quality using Skindex-29, preventive care is necessary for cleanroom workers in ultralow humidity environment.

To measure the prevalence of dry eye syndrome (DES) among clean room (relative humidity ≤1%) workers from 2011 to 2013.

Three annual DES examinations were performed completely in 352 clean room workers aged 20–40 years who were working at a secondary battery factory. Each examination comprised the tear-film break-up test (TFBUT), Schirmer’s test I, slit-lamp microscopic examination, and McMonnies questionnaire. DES grades were measured using the Delphi approach. The annual examination results were analyzed using a general linear model and post-hoc analysis with repeated-ANOVA (Tukey). Multiple logistic regression was performed using the examination results from 2013 (dependent variable) to analyze the effect of years spent working in the clean room (independent variable).

The prevalence of DES among these workers was 14.8% in 2011, 27.1% in 2012, and 32.8% in 2013. The TFBUT and McMonnies questionnaire showed that DES grades worsened over time. Multiple logistic regression analysis indicated that the odds ratio for having dry eyes was 1.130 (95% CI 1.012–1.262) according to the findings of the McMonnies questionnaire.

This 3-year trend suggests that the increased prevalence of DES was associated with longer working hours. To decrease the prevalence of DES, employees should be assigned reasonable working hours with shift assignments that include appropriate break times. Workers should also wear protective eyewear, subdivide their working process to minimize exposure, and utilize preservative-free eye drops.