Is air contamination only cause of these symptoms?

Air quality news from lanjia laser particle counter
No. Feelings of discomfort and illness may be related to any number of issues in the total indoor environment.
Other common causes may include noise levels, thermal comfort (temperature, humidity, and air movement),
lighting, and ergonomics. It is important that all possible causes be investigated when assessing complaints.
Other OSH Answers documents on these topics include:
Noise - General
Thermal Comfort for Office Work
Office Ergonomics - Eye Discomfort in the Office
Ergonomics
Lighting Ergonomics - General
Particle counter let you know good or bad indoor environment which you living.