**7. Conclusion**

Particulate matter exposure that occurs indoors probably constitutes a significant fraction of the overall exposure to hazardous particles since typically people spend most time indoors. The indoor settled as well as suspended particulate matter was monitored and particles morphology and chemical composition with special regard to metal content investigation was performed.


The results demonstrate the complexity of indoor particulate matter nature affecting their surface properties. The results also emphasise the need for further research to a more complete understanding of the chemical nature of indoor particulate matter in connection with their surface reactivity. Due to the negative biological influence of particulate matters and their specific properties resulting in synergic effect of the other pollutants in the indoor air it is necessary to investigate the ways of indoor particulate matters occurrence minimization and/or elimination.
