ABSTRACT
The purpose of this study was to determine the indoor air quality (IAQ) status of an automotive assembly plant in Rawang, Selangor, Malaysia using selected IAQ parameters, such as carbon dioxide (CO2), carbon monoxide (CO), temperature, relative humidity (RH) and respirable particulate matter (PM10). A cross-sectional study was conducted in the paint shop and body shop sections of the plant in March 2005. The Q-TRAK Plus IAQ Monitor was used to record the patterns of CO, CO2, RH and temperature; whilst PM10 was measured using DUSTTRAK Aerosol Monitor over an 8-hour time weight average (8-TWA). It was found that the average temperatures, RH and PM10 in the paint shop section and body shop sections exceeded the Department of Safety and Health (DOSH) standards. The average concentrations of RH and CO were slightly higher in the body shop section than in the paint shop section, while the average concentrations of temperature and CO2 were slightly higher in the paint shop section than in the body shop section. There was no difference in the average concentrations of PM10 between the two sections.
ABSTRACT
The JCQ has been shown to be a valid and reliable instrument to assess job stress in many occupational settings worldwide. In Malaysia, both the English and validated Malay versions have been employed in studies of medical professionals and laboratory technicians, respectively. The present study assessed the reliability and construct validity of the Malay version of the JCQ among automotive workers in Malaysia. Fifty workers of a major automotive manufacturer in Kota Bharu, Kelantan consented to participate in the study and were administered the Malay version of the JCQ. Translation (English-Malay) and back translation (Malay-English) of the JCQ was made to ensure the face validity of the questionnaire. Reliability was determined using Cronbach's alpha for internal consistency, whilst construct validity was assessed using exploratory factor analysis (principal component with varimax rotation). The results indicate that the Cronbach's alpha coefficients were acceptable for decision latitude (job control or decision authority) (0.74) and social support (0.79); however, it was slightly lower for psychological job demand (0.61). Exploratory factor analysis showed 3 meaningful common factors that could explain the 3 theoretical dimensions or constructs of Karasek's demand-control-social support model. In conclusion, the results of the validation study suggested that the JCQ scales are reliable and valid for assessing job stress in a population working in the automotive industry. Further analyses are necessary to evaluate the stability and concurrent validity of the JCQ.