Non-Industrial Indoor Air Quality and Development of Basic Methods for the Occupational Risk Assessment. Summary of the Doctoral Thesis

Abstract

The paper consists of 162 pages, 75 pictures, 86 tables, 161 literature references, 10 attachments. The thesis is completed in Latvian. Aim of Study: to assess the non-industrial workplace indoor air quality indicators and detection methods, as well as set the science-based methods for non-industrial workplace indoor air quality and assess the health complains of workers. Methods and Materials: there have been used internationally recognized indoor air quality assessment methods and equipment in study, as well as the first time in the occupational environment of Latvia were estimate dust particle count and surface area concentrations. The employee‘s survey was done to evaluate impact of indoor air quality and health complaints in offices. The dust particles (include nanoparticles) potential effects on office workers' health was conducted by experiments in vivo (rats) and in vitro (cells). Main Results: the measurement results of indoor air quality indicated that the most important indoor air pollutants in offices are: CO2, formaldehyde, hydrocarbons (by C), ethyl acetate, the count of dust particles (nanoparticles), surface area of dust alveolar fraction. NO2 and O3, as well as humidity, temperature and air velocity should be taken in account by evaluation of the non-industrial occupational environment of workplaces. Data of measurements and survey indicated a strong correlation between CO2 concentrations and specific health complaints (difficulty concentrating, fatigue, headaches, etc.). The survey results also indicated that poor indoor air quality in offices gave the higher odds ratio for such health complains as: dry skin (OR = 3.4) and dry and itchy eyes (OR = 2.5) in case of low air humidity; nausea or feeling sick (OR = 2.6) and sore, dry throat (OR = 2.6) in case of chemicals exposure; sneezing (OR = 2.2) in case on low air velocity etc. However, considering that age and sex play a role in the development of health symptoms (neck fatigue, back pain, etc.). The experiments in vivo showed statistically significantly increasing of inflammatory indicators, changes of immune-competent cells, it shows that inflammatory process in lung is offset. Cell‘s fragmentation was observed after exposure to nanoparticles in peripheral blood mononuclear cells. In general, long-term and systematic impact of poor non-industrial indoor air can cause health complaints to office workers.