Biga, nestled in the Çanakkale province of Turkey, occupies a geographically significant position within the Marmara Region. Located at approximately 40.23° N, 27.24° E, the city’s terrain is characterized by rolling hills and valleys, a consequence of its placement within the Northwestern Anatolian Fold Belt. The elevation varies, with the city center situated around 150 meters above sea level, gradually rising towards the surrounding hills. This undulating landscape influences local wind patterns, sometimes creating pockets of stagnant air, particularly during periods of calm weather. Biga’s proximity to the Marmara Sea, roughly 60 kilometers to the north, introduces a maritime influence, moderating temperatures and occasionally bringing in sea breezes that can disperse pollutants. The surrounding landscape is a blend of agricultural land – primarily olive groves and wheat fields – and scattered woodlands, contributing to a rural-urban gradient. To the east, the mountainous terrain of the Kaz Dağları (Mount Ida) acts as a barrier, potentially trapping pollutants under certain meteorological conditions. While Biga isn't directly adjacent to major industrial belts, it serves as a regional agricultural hub, and transportation routes connecting it to larger industrial centers like Istanbul and Izmir pass nearby, contributing to localized traffic-related emissions. The urban character is relatively compact, with a traditional town center gradually expanding outwards, impacting the surrounding agricultural land and influencing the overall air quality dynamics.

Biga’s air quality experiences a distinct seasonal cycle heavily influenced by its Mediterranean climate with continental characteristics. Summers (June-August) are typically hot and dry, with minimal rainfall. This lack of precipitation, coupled with high temperatures, can lead to a build-up of pollutants, particularly those from agricultural activities like pesticide spraying and dust from unpaved roads. Stagnant air masses are common during these months, exacerbating the issue. Autumn (September-November) brings a gradual shift, with increased rainfall and more frequent wind events that help to disperse pollutants. However, agricultural burning, a traditional practice for land clearing, can contribute to localized spikes in particulate matter. Winter (December-February) often sees the most challenging air quality conditions. Temperature inversions, where a layer of warm air traps cooler air near the ground, are frequent, preventing vertical mixing and concentrating pollutants. Fog, common during these months, further reduces visibility and traps emissions. Spring (March-May) generally offers the best air quality, with increasing rainfall, stronger winds, and rising temperatures that promote dispersion. Sensitive groups, including children, the elderly, and individuals with respiratory conditions, should exercise caution during the summer and winter months, limiting outdoor activity during peak pollution periods. Avoiding strenuous exercise on days with visible haze or reduced visibility is also advisable. Agricultural workers should be particularly mindful of pesticide exposure during the summer months, utilizing appropriate protective equipment.