(1) Background: Musculoskeletal disorders have a multifactorial etiology that is not only associated with physical risk factors, but also psychosocial risk factors; (2) Objective: This study evaluated the effects of an ergonomic intervention on musculoskeletal disorders and psychosocial risk factors; (3) Material and Methods: This study took a participatory ergonomic (PE) approach with a randomized controlled trial (RCT) conducted at tertiary care hospitals during July to December 2014. A group of hospital orderlies in Thailand were randomly selected for examination. Fifty orderlies were placed in a case group and another 50 orderlies were placed in the control group. The Nordic Musculoskeletal Disorders Questionnaire (NMQ) and the Copenhagen Psychosocial Questionnaire (COPSOQ) were used for data collection before and after the intervention program; (4) Results: The most commonly reported problem among hospital orderlies was found to be lower back symptoms (82%). The study found significant differences in prevalence rates of reported musculoskeletal conditions in the arm, upper back, and lower back regions before and after intervention. Findings showed that psychosocial risk factors were affected by the intervention. COPSOQ psychosocial risk factors were significantly different pre/post intervention. These variables included: work pace, influence at work, meaning of work, predictability, rewards, role conflicts, and social support from supervisors. No other psychosocial risk factors were found to be significant; (5) Conclusions: Positive results were observed following the intervention in the work environment, particularly in terms of reducing physical work environment risk factors for musculoskeletal disorders and increasing promotion factors of the psychosocial work environment.

Objectives: Most workers in auto part factories in Thailand are usually exposed to excessive noise in their workplace. This study aimed to assess the level of occupational noise-induced hearing loss and investigate risk factors causing hearing loss in auto part factory workers in the welding units in Thailand. Methods: This was a cross-sectional study. One hundred eighty subjects were recruited from 356 workers in the welding unit of three factories. Sixty eligible subjects in each factory were selected by systemic random sampling. The subjects were interviewed using a face-to-face questionnaire. Noise exposure levels and audiograms were measured by a noise dosimeter and an audiometer, respectively. Results: The findings confirmed that noise exposure levels of 86-90 dB (A) and exceeding 90 dB (A) significantly increased the risk of hearing loss in either ear. A noise exposure level exceeding 90 dB (A) significantly increased the prevalence of hearing loss in both ears. Regarding, a 10-pack-year smoking history increased the prevalence of hearing loss in either ear or both ears. In addition, subjects with employment duration exceeding 10 years significantly developed hearing loss in either ear. Conclusions: Th engineering control or personal control by wearing hearing protection device should be used to decrease noise exposure levels lower than 85 dB (A) for 8 h. Moreover, if the exposure level reaches 85 dB (A) for 8 h, the employer needs to implement a hearing conservation program in the workplace.