Exposure to noise and whole-body vibration (WBV) has been a key element in determining comfort levels in transportation systems. In the automotive industry, researchers and engineers continuously work on reducing noise and vibration levels to minimize discomfort. Noise annoyance in vehicles results from structure-borne as well as air-borne noise from vehicle powertrain, tires and aeroacoustics. Whole-body vibration affects vehicle passenger comfort at the seat pan, back rest and feet. The objective of this research is to evaluate the comfort level of seated passengers in a vehicle from noise and whole-body vibration by considering both separate and combined modality. The noise and vibration data were recorded and analysed in two vehicles on the same highway road with four different speeds. The vibration exposure in vehicle were evaluated based on ISO2631-1:1997. Noise exposure was based on A-weighted sound pressure level. The combined discomfort on noise and vibration were quantified. The vibration results identified clear dominant of z-axis vertical vibration on seat pan, backrest and feet in both vehicles. The discomfort of combined noise and vibration showed that vehicle B caused a higher discomfort level at the high vehicle speed of 90 km/h and 110 km/h. The Relative Discomfort Indicator (RDI) were introduced to compare levels of discomfort from noise and vibration in different vehicles with varying speeds. The result suggests that the RDI value for vehicle A relative to vehicle B is negative at higher vehicle speed which further indicates that at higher speed, vehicle B have a higher discomfort level compared to vehicle A. The RDI value is expected to be useful for automotive Noise, vibration and harshness (NVH) improvement.

In the shoes industry, benzene constitute as one of the source of chemical hazard especially used in the gluing section. This compound is metabolized by the liver, forming free radicals in the body which can ultimately reduce the concentration of glutathione and increased malondialdehyde causing DNA degeneration. The purpose of this study was to determine the relationship between benzene concentration, excess cancer risk (ECR), malondialdehyde, glutathione, and DNA degeneration among workers in shoes industry in Osowilangun, Surabaya. This is an observational study with a cross-sectional design. The number of research samples was 25 respondents. The average concentration of benzene in workers was above the threshold (10.31 ppm). There were 15 (60%) respondents with ECR >0.0001 who experienced DNA degeneration. There was no relationship between benzene concentration, malondialdehyde, glutathione, and DNA degeneration. However, there was a relationship between benzene ECR, malondialdehyde, glutathione, and DNA degeneration in the shoe industry workers in Osowilangun.

This study found that the workers had good KAP levels of risk management of steam boilers in palm oil mills. However, there is a need for the employers to revise the training of workers and ensure its effectiveness in heightening the awareness of risks and accidents despite the high level of KAP.

The unpopularity of the current hard hat among oil palm harvesters stemmed from the discomfort from wearing, which showed that the development of a new hard hat could lead to better usage and the greater likelihood of wearing a hard hat throughout the working day.

The human discomfort from combined noise and vibration has been investigated with a new perspective. The concept in perturbation effect has been adopted to formulate a new novel predictive model of human discomfort from noise and vibration. A psycho-physics experiment has been designed to identify the perturbation effect which caused by noise stimulus. The experiment involved twelve (12) subjects. Each subject was imposed in random order with a total of 42 combinations of seven (7) levels of noise (X, 61, 71, 77, 84, 87, 89 dBA) where the X is no noise stimulus, and six (6) levels of vibration dose values (V1 = 0.2079, V2 = 0.3242 V3 = 0.6388 V4 = 0.8803 V5 = 1.4947 and V6 = 1.8624 m/s1.75). Initially, the subject would be imposed with a reference combination of noise and vibration which was assumed to have a value of 100. The assigned combination for reference was chosen at sound exposure level, LAE of 71 dB(A) and the vibration dose value, VDV of 0.2079 ms−1.75. Then the subject was imposed with other combinations of noise and vibration in a duration of 5 s and 5 s break in between the stimuli combination. After each exposure to each combination of noise and vibration, the subject is required to state the discomfort caused by the noise and vibration in the form of a number relative to the reference stimuli of 100. The subject was asked to be seated in a relaxed position, holding a handphone and used it to record all the response values after each stimulation. The finding suggested that the discomfort from vibration can be predicted with equation ψv=170.6082avdv0.6662 and the overall discomfort from noise and vibration is given by ψv−n=ψv+ψvε where the ε is the perturbation effect caused by noise stimulus.