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Selmana, nestled within the Djelfa Province of Algeria, occupies a geographically significant position on the fringes of the Saharan Atlas mountains. Located at approximately 34.18°N, 3.60°E, the city’s elevation of around 750 meters above sea level contributes to a unique microclimate and influences its air quality dynamics. The surrounding landscape is characterized by a transition zone between the arid Sahara Desert and the more fertile plains of northern Algeria. To the west and south, the vast expanse of the Sahara dominates, impacting Selmana with frequent dust intrusions. Eastward, the foothills of the Saharan Atlas rise, creating a terrain of undulating hills and valleys. This mountainous backdrop can trap pollutants under certain meteorological conditions. Selmana’s proximity to agricultural zones, particularly olive groves and cereal farms, introduces biogenic volatile organic compounds (BVOCs) and potential agricultural dust into the atmosphere, especially during planting and harvesting seasons. While not directly adjacent to major bodies of water, the region experiences occasional rainfall, which can temporarily cleanse the air. The urban–rural gradient around Selmana is relatively sharp; the city itself is a small, localized settlement, quickly giving way to agricultural land and then the stark beauty of the desert. The absence of large-scale industrial belts within immediate proximity is a mitigating factor, though regional transportation routes can contribute to vehicular emissions. The prevailing winds, often originating from the Sahara, are a crucial factor in determining the city’s air quality, frequently carrying fine particulate matter.

Selmana’s air quality exhibits a distinct seasonal pattern dictated by its semi-arid climate and regional weather systems. Spring (March-May) typically sees a gradual improvement in air quality as temperatures rise and rainfall becomes less frequent, though dust storms from the Sahara remain a possibility. Summer (June-August) is generally characterized by hot, dry conditions and relatively stable atmospheric layers, which can lead to pollutant accumulation, particularly during periods of stagnant air. The intense solar radiation promotes photochemical reactions, potentially increasing ozone levels. Autumn (September-November) often brings a period of improved air quality as winds increase and dust events become less intense. However, agricultural activities, such as harvesting, can temporarily elevate particulate matter concentrations. Winter (December-February) is arguably the most challenging period for Selmana’s air quality. Cold temperatures frequently lead to temperature inversions, trapping pollutants near the ground. Fog, though infrequent, can exacerbate this effect, reducing visibility and increasing the concentration of fine particulate matter. Sensitive groups, including children, the elderly, and individuals with respiratory conditions, should exercise caution during winter months, limiting outdoor activity on days with poor visibility or stagnant air. During the hotter months, staying hydrated and avoiding strenuous activity during peak sunlight hours is advisable. The frequency of dust intrusions from the Sahara is a constant factor throughout the year, requiring residents to monitor local weather reports and take appropriate precautions, such as wearing masks when dust storms are anticipated.