Human Factors and Ergonomics Journal (HFEJ)

Volume 8, No. 1 (2023)

Published online on 30 June 2023


The Use of Principal Component Analysis (PCA) In Determining Factors Related To Heat Stress Related Symptoms Among Steel Mill Workers In Hot Tropical Countries

Imam Munajat Nurhartonosuro1, Shamsul Bahri Md Tamrin1,*, Dayana Hazwani Mohd Suadi Nata2, Karmegam Karuppiah1, Ng Yee Guan1, Gede Pramudya Ananta3

Page 1 – 24   |   Available online on 30 June 2023

Abstract: Heat stress related symptoms are commonplace workers experience heat strain due to heat stress occurring at workplaces. Steel mill workplaces have an extremely high operating temperature around 1800oC, thus operators are most likely to be exposed to hot environments. The study aimed to apply principal component analysis (PCA) in predicting the heat stress symptom model among steel mill workers. Data including environmental variables (WBGT, relative humidity, air temperature; related symptoms), physiological changes (blood pressure of systolic and diastolic, heart rate, and body core temperature) at three steel mills located in East Java, Indonesia, where operators might experience were used in PCA. Based on the principal component analysis (PCA) result, there are three variables that have a strong correlation (> 0.5) with factor 1, namely WBGT, relative humidity and body core temperature. The three variables are then grouped into factor 1; Furthermore, the other two variables have a strong correlation with factor 2, namely blood pressure systolic and diastolic. In conclusion, PCA is able to determine the prediction of heat stress symptoms and is simplified to be used by the steel mill industries.

Khairul Nazri Abd Wahib1, Shamsul Bahri Mohd Tamrin1

Page 25 – 43  |   Available online on 30 June 2023

Abstract: Agricultural activities have always been associated with hazards and injuries especially in oil palm plantation where the upstream tasks are majorly manual and labour intensive. Harvesters are exposed to danger when cutting the fresh fruit bunches (FFB) from the tree during harvesting. The height of the palm tree, as well as the quantity and weight of the FFB might injure oil palm harvesters severely where head injury is the main concern. However, due to thermal discomfort associated with working in an unpleasantly hot environment, harvesters tend to take off their safety helmet in which the act poses high risk to injury. Objective: This paper shows how an industrial design safety helmet shell was redesigned to improve its thermal qualities while still satisfying other critical safety helmet standards. Method: The design requirements were first gathered. Industrial design and mechanical design were attentively generated utilizing Computer Aided Design software. Structural and thermal analysis were simulated employing Computer Aided Engineering software, iteratively modelled and analysed for an optimally designed safety helmet to satisfy all the identified requirements. Notwithstanding that the absence of regulatory standard for thermal comfort, design detailing and engineering analysis effort was conducted to ensure thermal discomfort is significantly reduced to meet the targeted specification. Results: High fidelity prototypes were fabricated; field test was conducted to find the acceptability of the new helmet against the current existing helmets. The new safety helmet design was well accepted as there is a significance increase of acceptance level of parameter in day 1, day 3 and day 6 among oil palm harvesters. Conclusion: The well accepted newly proposed safety helmet for oil palm harvester not only solving thermal discomfort issue while being able to meet stringent safety requirements, but it also resolves all other addressed concerns. Safety helmet for use by oil palm harvesters should be modified to ensure the oil palm harvesters feel more comfortable, therefore encouraging them to wear them consistently during working, comply with existing regulations thus minimize injuries.

T.W.Z. Alastair1, M. Ismail2

Page 44 – 56  |   Available online on 30 June 2023

Abstract:  Previous studies have associated musculoskeletal discomfort (MSD) with decreased productivity at the workplace and affected workers in various occupations.  Evidence suggests a multi-factorial nature of MSD in terms of its development and exacerbation including physical, psychosocial, and individual factors. In addition, studies in both developed and developing countries also differ concerning the prevalence rate of MSD across countries. Hence, the present study aimed to examine the prevalence rate of MSD among female office workers in public organizations. A questionnaire survey was distributed to four fire stations in Kota Kinabalu Zone in Sabah and 130 firefighters participated in the study. The questionnaire consists of demographical aspects, task characteristics, physical demands, mental health, and musculoskeletal discomfort (MSD) levels. The 6 months MSD prevalence was 32.3% (95%CI = 30.9%-35.3%). The majority of the firefighters experienced MSD moderately in various body regions – lower extremity (14.6%), neck/shoulder (16.9%), hand/fingers (17.7%), arms (17.7%), and lower back (20%). The results reported the experience of firefighters with MSD highlighted the need to develop MSD risk management at the workplace. In addition, further examination of MSD among firefighters in Malaysia should be conducted to minimise MSD in the workplace.


Tee Sin Er1, Nurul Ainina Nadhirah Tajurahim1, Salwa Mahmood1*, Ismail Abdul Rahman2

Page 57 – 79  |   Available online on 30 June 2023

Abstract: Office ergonomics provides an arbitrary framework for integrating a large body of research that is relevant to the design of office work environment to optimize the health, safety, comfort, and effectiveness of human occupants . This paper involves office workers in the Faculty of Engineering Technology (FTK) at Universiti Tun Hussein Onn Malaysia (UTHM). The main objective of this paper is to determine the risk level of the office designed during the working daily time using Rapid Office Strain Assessment (ROSA) technique. This paper applied ROSA technique for estimating the risk factor exposure in office workers. A set of questionnaires consisting items on working experience, work-related posture, and work-related pain was distributed to a total of forty (40) respondents among office workers from FTK UTHM. It was found that seventy–five percent (75%) of respondents had work-related pain in their part of body such as the neck, shoulder, wrist, lower back, hip, and knee. Besides, the significant level risk of respondent B and C were deemed high-risk; five (5) and six (6) scores, respectively, implying that respondents’ workstations should be evaluated further in terms of office ergonomic design. Therefore, it is suggested in this study that when designing a workstation, the principle of motion economy be taken into account to ensure that the standard assessment is met.

Gan Xie Li1, Mohd Hafiidz Jaafar1*, Ahmad Sufril Azlan Mohamed2, Nur Zaidi Azraai3 and Norhaniza Amil1

Page 80- 96  |   Available online on 30 June 2023

Abstract: Introduction: The selection of suitable ergonomics risk assessments (ERA) is significant in producing significant results. The study’s main objective is to analyse the suitability of ERA methods for evaluating the risk level of above-shoulder reaching during the HS binning process through the application of marker-based motion capture. Materials and Methods: Methods selected for this study are RULA, REBA, NERPA, MAC, QEC and RNLE. Three participants were chosen to wear a Mocap suit with 25 markers placed on joints and rigs. The participants performed above-shoulder reaching with a load of 2.1 kg at 2.05 m height. RULA is acting as a basis for comparison for this study. Result: RULA rated the posture majority (66.67%) as “high risk”. Conclusion: Based on the Mann-Whitney U Test, RULA, REBA, and NERPA proved that they are suitable for evaluating above-shoulder reaching during the HS binning process.

Mohd Hafiidz Jaafar1*, Kadir Arifin2, Kadaruddin Aiyub2, Mohamad Shaharudin Samsurijan3, Widad Fadhullah1 and Mohamad Firdaus Bin Samsudin3

Page 97 – 117  |   Available online on 30 June 2023

Abstract: Malaysian economy depends heavily on the contribution of the construction industry. This sector contributes to high occupational fatalities in Malaysia. Immediate (human and worksite) and underlying (management and external) causes contribute to occupational accidents and illnesses. The study’s main aim is to analyse local construction personnel’s perspective on the causes (immediate and underlying) of Malaysian construction accidents and illnesses. 13 housing projects were selected in Pulau Pinang. A survey questionnaire supported by in-depth interviews was conducted. The immediate causes comprising human and worksite elements were perceived as most significant, with mean values of 3.45 and 3.58, respectively. Significant correlations between the two-level of causes (immediate and underlying) are registered in the study. The effect on construction accidents and illnesses derived from underlying causes is not as obvious as the impact of human and worksite elements.