Hi, Meegaswatta hope this answer solve your problem,

Obviously, according to EPA (United States Environmental Protection Agency), air quality and its pollution level are strongly correlated with elevation and topographical factors. Atmospheric pressures in places with surface elevations above 1200-1500 metres are about 12-18% lower than pressures at sea level. The basics of atmospheric science is that Atmospheric pressure decreases as the height of a surface above ground level increases because as the altitude increases, it results in the no. of air molecules reduced and subsequently the weight of the air also reduced. Hence, it depends on your device through which you examine the level of PM2.5 & PM10. As per my suggestion, you should calibrate the device readings from three different elevations at the same location and later validate them using comparing the values which are more accurate.

Agree with Dr. Roy, and I should mention air pollution is not my professional specialty. Most air quality stations I have seen are in one location, but with various elevations of instruments (such as for example eye level, shrub height or mid canopy and top of tree canopy if forested). I suppose some might use weather balloon to sample higher, depending on your study goals. Air quality elements can be plotted against elevation. Normally other factors such as temperature, relative humidity, wind speed, and barometric pressure would be also measured so factors such as air inversion can be detected, which tends to hold smoke and particulates closer to the ground. I suppose there have been numerous case studies describing severe traffic accidents due to heavy smoke or fog during inversions. A one acre area is really not large enough to have much topography anyway. I know that USFS air quality and fuel (fire) management specialists use several models to predict air quality conditions relative to prescribed burning. Smoke management tries to avoid conditions that contribute to excessive development of fog or smog, impacting individuals with breathing issues, and burn in conditions where the smoke rises well above the nearby community, roads, hospitals, etc.

Lower location points can act as trapping centers and you my record higher pollution in there as compared to high elevation points where the flow is much easier.

Dear Dhanushka,

I suggest you select three locations from the various elevations. This approach is better because recent studies have recorded high concentrations of multiple pollutants at lower elevation sites, and a positive association between inversion frequency and particulate concentration.

Thanks, Charles Obinwanne Okoye Aman Arora William F. Hansen Subham Roy much appreciate all of your answeres