Assessment of thermal comfort in a hot and humid indoor built environment of a kitchen at a university canteen.

BACKGROUND: The hot and humid environment inside the kitchen is a cumulative sign of health impact that deteriorates the well-being and productivity of cooking workers, which could be a barrier to thermal comfort. As the cooking task progresses throughout the day, uncomfortable thermal conditions inside a kitchen work environment may diminish the work quality of the kitchen workers. OBJECTIVE: The objectives of the study were to evaluate the measured environmental factors of thermal comfort during various cooking periods [morning, day, evening, night] and examine the occupant's perception votes followed by further investigating the worker's thermal comfort conditions using PMV, PPD, SET, WBGT, and TSI indices. METHODS: The study was carried out inside the kitchen of the university canteen at IIT Guwahati, India. The objective and subjective measurements were accomplished during the summer season, while CBE thermal comfort software was employed for calculating the thermal comfort indices like PMV, PPD, and SET. RESULTS: The results of this study revealed that during entire cooking time, the recorded environmental factors of thermal comfort were found outside the recommended limits as per ASHRAE-55 standard, which indicates very hot prevalent conditions. Also, cook's perception vote (TSV, TCV) for the existing environment did not follow the central three categories of votes (+1, 0, -1), even the cooking workers were also not satisfied with the prevailing environmental conditions, as 88% subjects responded dissatisfaction with the thermal environment. While, estimated values of thermal comfort indices (PMV, PPD, and SET) designated morning time cooking period slightly comfortable than the other cooking periods, but still not accordance with the ASHRAE-2017 standard. The WBGT index designated day cooking period as hazardous, with rest of cooking periods under severe risk level. In contrast, the TSI index indicated entire cooking periods under "slightly warm" thermal sensation. CONCLUSION: The assessment of this study showed that the existing kitchen environment of the university canteen is not conducive for workers. Improper ventilation design may cause the overheating inside the kitchen, which may increase the dissatisfaction rate of the employed workers and also affects the energy savings in the kitchen environment, which helps maintain thermal comfort. Further studies are required to improve the thermal comfort of the kitchen occupants by providing proper design interventions based on heating and cooling air ventilation systems.

Ergonomics and efficient workplace design for hand-sewn footwear artisans in Kolhapur, India.

BACKGROUND: The footwear manufacturing industry is one of the significant sectors of leather businesses in India. In the Indian footwear production industry, there is an enormous potential for employment, export, and development. Kolhapuri footwear is a popular handmade craft in India. It is a well-designed craft used by Indian people for many years. Artisans using traditional tools manufacture this footwear manually. Workers of this craft use traditional methods and work in cottage-based enterprises where organized laws and legislations are not applicable. Therefore, any occupational hazard-related documentation is not available. Due to the nature of the job, workers occupy various apparent non-optimal postures that may cause multiple work-related disorders such as musculoskeletal disorders (MSDs). OBJECTIVE: The main objective was to study and assess different footwear manufacturing workstations and working postures. The work further aimed to improve the design of current workstations and evaluate the proposed design using virtual ergonomic assessment techniques. METHODS: An anthropometric database for the Kolhapuri footwear making population was developed. This work measured 35 different body dimensions of the footwear manufacturing artisans. Rapid Upper Limb Assessment (RULA) was used for postural analysis of the artisans. RESULTS: It was observed that the entire footwear making activity was carried out in awkward postures. RULA scores suggested that 'a change in posture' to improve the efficiency of artisans was required for most of the workstations. This work proposed a novel workstation design to reduce the high risk of MSDs. The design was evaluated for thigh clearance, vision analysis and RULA analysis with the help of Digital Human Modelling (DHM). The virtual ergonomics assessment of this design revealed that the vision, thigh clearances, and RULA scores were satisfactory in the new design. CONCLUSION: The anthropometric database proposed in this study is likely to be useful in designing Kolhapuri footwear manufacturing tools. The proposed workstation and work layout are helpful to improve the accessibility of required tools and materials to footwear workers. It also helps to reduce occupational risks by easing uncomfortable work positions.

DETERMINATION OF THE OPTIMAL DURATION OF WORK EXPOSURE WHILE SITTING IN A SQUATTING POSITION TO AVOID LOW BACK PAIN: A SIMULATION STUDY.

The objective of this stuay was to determine the optimal duration of work exposure while sitting in a squatting posture. A simulation study was formulated on work similar to the traditional jewellery manufacturing activity. The task of metal setting was simulated in a controlled environment. Fifteen young adult males participated in this study. The results of 12 participants were included as others discontinued the study for their personal reasons. The study continued for 2 hours. Trunk muscle strength and body part discomfort (BPD) were measured before and after completion of the task. BPD ratings in CR 10 scale were also collected after each 15 minutes of work. The mean age (year), height (cm), weight (kg) and BMI (kg/n2) of the subject were 24.25 ± 2.14, 172.47 ± 3.88, 65.08 ± 4.52 and 21.88 ± 1.33, respectively. Using inferential statistics, a predictive equation was developed to determine the optimal duration of exposure in a squatting position similar to traditional jewellery manufacturing activity. An hour of work with a small break was suggested after considering the study result for the workers who worked in a squatting posture like traditional jewellery manufacturing.

Vision-related problems among the workers engaged in jewellery manufacturing.

BACKGROUND: American Optometric Association defines Computer Vision Syndrome (CVS) as "complex of eye and vision problems related to near work which are experienced during or related to computer use." This happens when visual demand of the tasks exceeds the visual ability of the users. Even though problems were initially attributed to computer-related activities subsequently similar problems are also reported while carrying any near point task. Jewellery manufacturing activities involves precision designs, setting the tiny metals and stones which requires high visual attention and mental concentration and are often near point task. It is therefore expected that the workers engaged in jewellery manufacturing may also experience symptoms like CVS. AIM: Keeping the above in mind, this study was taken up (1) To identify the prevalence of symptoms like CVS among the workers of the jewellery manufacturing and compare the same with the workers working at computer workstation and (2) To ascertain whether such symptoms have any permanent vision-related problems. SETTING AND DESIGN: Case control study. MATERIALS AND METHODS: The study was carried out in Zaveri Bazaar region and at an IT-enabled organization in Mumbai. The study involved the identification of symptoms of CVS using a questionnaire of Eye Strain Journal, opthalmological check-ups and measurement of Spontaneous Eye Blink rate. The data obtained from the jewellery manufacturing was compared with the data of the subjects engaged in computer work and with the data available in the literature. STATISTICAL ANALYSIS: A comparative inferential statistics was used. RESULTS AND CONCLUSION: Results showed that visual demands of the task carried out in jewellery manufacturing were much higher than that of carried out in computer-related work.

Prevalence of musculoskeletal discomfort among the workers engaged in jewelry manufacturing.

BACKGROUND: The workers engaged in jewellery manufacturing exposed to various occupational risk factors that lead to development of musculoskeletal disorders. But there is scarcity of reporting the prevalence of the musculoskeletal disorders among them. AIMS: To evaluate the prevalence of musculoskeletal discomfort among the workers engaged in jewellery manufacturing in India. SETTING AND DESIGN: Case Control Study. MATERIALS AND METHODS: This study was divided into two phases. First phase: prevalence rate were calculated using Modified Nordic musculoskeletal questionnaire and compared with the control group. Second phase: strength, flexibility and tightness of the muscle groups (neck, lower back and knee) were evaluated through physical examination for the subjects who reported positive prevalence. STATISTICAL ANALYSIS: A comparative inferential statistics was used. RESULTS: This study was divided into two phases. First phase: prevalence rate were calculated using Modified Nordic musculoskeletal questionnaire and compared with the control group. Second phase:strength, flexibility and tightness of the muscle groups (neck, lower back and knee) were evaluated through physical examination for the subjects who reported positive prevalence. CONCLUSIONS: The musculoskeletal disorders among the workers engaged in jewellery manufacturing were found to be specific to the occupation.