Perunkalattu, nestled in the state of Tamil Nadu, India, occupies a geographically significant position within the Kaveri Delta, a fertile and densely populated region. Located at approximately 12.9182° N, 80.0824° E, the city’s terrain is predominantly flat, characteristic of deltaic landscapes, with an average elevation of just a few meters above sea level. This low elevation contributes to a tendency for pollutants to accumulate, particularly during periods of stagnant air. The surrounding landscape is dominated by agricultural fields – rice paddies are ubiquitous – interspersed with smaller villages and pockets of rural settlement, creating a gradual urban-rural gradient. The Kaveri River, a vital lifeline for the region, flows relatively close to Perunkalattu, influencing local climate and potentially impacting air quality through humidity and occasional flooding events. While Perunkalattu itself is a relatively small urban centre with a population of around 25,864, it’s situated within a broader industrial belt that stretches along the Kaveri River, encompassing several manufacturing units and processing facilities. These industries, while contributing to the regional economy, represent a potential source of air pollutants. The proximity to agricultural zones also means that seasonal burning of crop residue, a common practice, can significantly impact air quality, particularly during the post-harvest season. The flat topography and surrounding agricultural and industrial landscape combine to create a setting where air pollution can be readily trapped and dispersed slowly, making local air quality management a crucial concern.

Perunkalattu’s tropical climate dictates a distinct wet and dry season pattern, profoundly influencing its air quality. The dry season, typically spanning from March to May, is often characterized by higher temperatures and reduced rainfall. This period frequently witnesses a build-up of pollutants due to decreased atmospheric cleansing through precipitation. Temperature inversions, common during these months, trap cooler air near the ground, preventing the vertical dispersion of pollutants released from agricultural burning and nearby industrial activities. The resulting stagnant air conditions exacerbate the problem. Conversely, the monsoon season, from June to September, brings relief through frequent rainfall, effectively washing away particulate matter and reducing overall pollution levels. However, the onset of the monsoon can initially be accompanied by increased humidity, which can exacerbate respiratory issues for sensitive individuals. The transitional months of October and November see a gradual decrease in rainfall and a slight cooling of temperatures, but the lingering effects of agricultural burning can still contribute to elevated pollution levels. Fog, particularly in the cooler months (December-February), can also trap pollutants near the ground, reducing visibility and impacting air quality. Individuals with pre-existing respiratory conditions, children, and the elderly are particularly vulnerable during the dry season and periods of fog. It’s advisable to limit strenuous outdoor activities during these times and to monitor local air quality reports. Maintaining indoor air quality through proper ventilation and air purification can also offer some protection.