This study reports levels of indoor environmental quality variables before and after installation of heat recovery ventilation in a primary school located in an urban area in Izmir, Turkey. A CO 2 -based modeling was performed to determine the required flow rates that would comply with an international ventilation standard, followed by computational fluid dynamics modeling for best airflow distribution in a classroom. Temperature, CO 2 , PM 2.5 , and total volatile organic compounds were found at undesired levels, among which relative humidity, CO 2 , and PM 2.5 were improved after the intervention. Reductions in the mean and maximum concentrations were 29% and 68% for CO 2 and 29% and 46% for PM 2.5 . This intervention study was a part of the city-wide main project that aimed to increase awareness of the students and their families, teachers, and staff regarding importance of indoor environmental quality in both at school and home due to its possible effects on children's health and academic performance, one of the major challenges of today's societies all around the globe.

Atmospheric levels of 43 PCBs, 22 OCPs, and 14 PBDEs were determined in 16 cities at urban and rural sites by passive sampling to generate the first large-scale nationwide dataset of POP residues in Turkey's atmosphere. Sampling campaign was performed from May to April 2015 with three-month sampling periods at locations on east-west and north-south transects through the country to investigate seasonal and spatial variations, including long range atmospheric transport (LRAT). Factor analysis was conducted to infer on the potential sources. Overall average Σ 43 PCBs concentration was 108±132 pg/m 3. PCB-118 (26.3±44.6 pg/m 3) was the top congener, and penta-CBs had the highest contribution with 54.3%. ΣDDTs had the highest annual mean concentration with 134±296 pg/m 3 among the OCP groups among which the highest concentration compound was p'p-DDE (97.6±236 pg/m 3). Overall average concentration of Σ 14 PBDEs was 191±329 pg/m 3 with the highest contribution from BDE-190 (42%). Comparison of OCPs and PCBs concentrations detected at temperatures which were above and below annual average temperature indicated higher concentrations in the warmer periods, hence significance of secondary emissions for several OCPs and Σ 43 PCBs, as well as inference as LRAT from secondary emissions. The first nationwide POPs database constructed in this study, point to current use, local secondary emissions, and LRAT for different individual compounds, and indicate the need for regular monitoring.