Assessment of occupational exposure to metal fumes and associated respiratory health symptoms among small scale welders in Dar es salaam

Abstract

Background: Occupational respiratory health symptoms are among the leading cause of occupational morbidity and mortality cases worldwide. Studies show that many workers in developing countries, who engaged in small scale welding operations in the informal sector, have been exposed to high level of multiple health hazards. This study therefore was designed to assess occupational exposure level to metal fumes containing Cadmium, Nickel and chromium, and associated respiratory health symptoms among small scale welders in Dar es Salaam. Methodology: a cross sectional study using quantitative approach employed the use of interview based questionnaires was conducted, observation checklist and laboratory analysis of 30 personal air samples (NIOSH 7300 Methods). A multistage sampling technique with probability methods was used to select study area (Districts, Wards and welding workplaces). A simple random sampling was used to select study participants. Data analysis was done using statistical package for social sciences (SPSS) version 16. Results: The study was involved 110 Male small scale welders from three Districts (Temeke, Ilala and Kindondoni) of Dar es Salaam Region with Mean age of 34±11.6 years and illiteracy rate of 1.8%. The prevalence of respiratory health symptoms highly reported were Cough 40%, Breathlessness 27.3%, phlegm 24.5%, Wheeze 24.5, and Chest tightness 24.5%. the study suggest that small scale welders were exposed to high mean concentration level above TLV limit for total metal fume 6.57±2.50mg/m3 but below the limit level for its elements; Cadmium (Cd) 0.00163 mg/m3, Chromium (Cr) 0.07346 mg/m3, and Nickel (Ni) 0.09809 mg/m3. The proportion of utilization of appropriate PRPEs among small scale welders was low (2%) and findings showed that there was statistical significant evidence (p<0.005) that welders who were not used PRPEs were 5 times likely to develop respiratory health symptoms compared to those who were used. Conclusion and Recommendation: This study was found high occupational exposure level to metal fumes among small scale welders in Dar es Salaam. Implementation of sound control measures at the source of fumes is highly encouraged in order to minimize exposure concentration to the safe acceptable level.