## 4 Discussion  
The impact of individual characteristics and environmental factors on the daily time-activity patterns and time spent indoors was assessed in an urban population in Kaunas, Lithuania. We examined randomly selected participants from the study population of Kaunas cohort according to their demographic, socioeconomic, environmental, behavioral, and health factors. Our analysis showed that individual-level characteristics have a significant impact on peoples' behaviors and time-activity patterns. The study results showed that age, occupational status, and gender were the most significant individual factors influencing time-activity patterns. Such behavioral characteristics as walking in leisure time, bicycle use, and car disposal had a statistically significant effect on the time spent walking and in transit. We determined that the most significant environmental variable influencing time spent outdoors and in transit was noise concentration. Overall, the results provide evidence that time management related behavior is influenced by both individual characteristics and environmental factors, thus, these variables should be taken into account when assessing exposure to various factors and evaluating health risks associated with this exposure. Similar results related with factors influencing residential indoor time was obtained by Reference [6]. Day type in both studies was associated with residential indoor time. [PERSON] et al. [6] found that employed, higher age, higher income and male participants spent significantly less time at home on the weekday. The present study results showed similar patterns that men, unemployed, and eldest people tend to spend most of their time at home. However, our study was more focused on the different aspects of behavioral and environmental factors that may influence time-activity patterns, while previous studies restrictively focused on a few microenvironments or evaluated only the influence of demographic and socio-economic factors on time-activity patterns. This is one of the main strengths of this study that the impact of behavioral and environmental factors on time-activity patterns and time spent indoors were evaluated. Additionally, the other strength of this study was that the time-activity patterns were objectively measured using GPS data and tracking participants' movement continuously throughout the week. Human activities and the characteristics of time-activity patterns are important determinants for personal exposure to environmental factors and future studies are needed to understand these relationships and its effect on exposure assessment. The study findings indicate that participants, on average, spent 93% of their daily time indoors (70% was spent at home) and only 7% of their time in other MEs such as outdoors, walking, and in transit. These results coincide with Canadian and American human activity pattern surveys [26; 27]. \begin{table}
\begin{tabular}{l c c c c} \hline \hline
**Variable** & **Crude OR** & **95\% CI** & **Adjusted \({}^{\dagger}\) OR** & **95\% CI** \\ \hline
**Walking in leisure time** & & & & \\ Yes & 1 & & 1 & \\ No & 2.14 & 0.94–4.88 & 2.77 \({}^{\star}\) & 1.09–7.05 \\ \hline
**Bicycle use** & & & & \\ Often & 1 & & 1 & \\ seldom & 3.32 \({}^{\star}\) & 1.20–9.18 & 3.86 \({}^{\star}\) & 1.28–11.66 \\ \hline
**Car disposal** & & & & \\ No & 1 & & 1 & \\ Yes & 0.96 & 0.46–2.00 & 1.36 & 0.59–3.16 \\ \hline
**Residential greenness** & & & & \\ Very/fairly & 1 & & 1 & \\ Little/not at all & 2.80 \({}^{\star}\) & 1.35–5.82 & 2.84 \({}^{\star}\) & 1.33–6.05 \\ \hline
**Noise concentration** & & & & \\ Lower than median & 1 & & 1 & \\ Higher than median & 1.97 & 0.97–4.01 & 1.76 & 0.84–3.72 \\ \hline \hline \end{tabular} \({}^{\star}\)_p \(<\) 0.05; \({}^{\star}\)_adjusted for: age, bicycle use, residential greenness, noise concentration.  
\end{table} 
Table 4: _Cont._[PERSON] et al. [28], in a study conducted in Italian urban area, found that people spent most of their time indoors at home.