INTRODUCTION
Respiratory system is the first tract that was harmed by toxic dust.
Prolong occupational exposure to the toxic dust could irritate the respiratory system, damage the lung tissues, create fibrotic tissues and impair lung function (Occupational respiratory diseases) such as asthma,asbestosis, silicosis etc.
In Thailand, occupational respiratory diseases have been increasing each year.
Wood processing from furniture factory caused wood dust and other health hazards including chemicals, bacteria and mold.
The dust are divided into 2 groups according to their size, the first is called “Total dust” which particle are larger than 10 micron (PM10), mainly are soft dust that could enter the upper respiratory tract and excreted by coughing or sneezing,7 another type is “Respirable dust” that has particle smaller than 10 micron(PM