Materials and MethodsStudy areaThe present study was conducted atcement factory (05°7'25"S; 38°58'23"E) inTanga city located in North-Eastern coast areaof Tanzania. The factory with over 300employees has manufacturing facility withoutput capacity of 80 tones per hour andproducts are mainly portland compositecement and cement products catering toconstruction industry. The factory alsooperates in three shifts hours per day for theworkers.