Scientists from Mahidol University believe that fine particulate matter smaller than 2.5 microns, or PM2.5, may cause osteoporosis.
Research found lab rats with this type of particulate in their bodies suffered from inflammation in their bones, they said.
The study was conducted by an osteoporosis-focused team at the Centre of Calcium and Bone Research (COCAB) at Mahidol University's Faculty of Science.
The research team hypothesised that the development of the bone disease could be largely attributed to inflammation due to cells in the immune system resisting PM2.5, which entered the lungs and other organs throughout the rats' bodies.
Scientists observed an increase of bone-degrading cells called osteoclasts in the lab rats.
These cells come from certain types of white blood cells and have an important role in decreasing bone mass, which could lead to osteoporosis.
The PM2.5 threat to human bones theory is in the process of being proposed for publication in international academic journals to prompt further research on treatment and prevention.
Apart from osteoporosis, PM2.5 can increase the severity of other chronic diseases, such as lung diseases and metabolic syndrome, as it contains a variety of particles and chemical substances, sources say.