Evaluation of Particulate Matter Pollution in Micro-Environments of Office Buildings—A Case Study of Delhi, India

High level of particulate matter in an office building is one of the prime concerns for occupant's health and their work performance. The present study focuses on the evaluation of the distribution pattern of airborne particles in three office buildings in Delhi City. The study includes the Assessment of PM10, PM2.5 and PM1 in the different indoor environments, their particle size distribution, I/O ratio, a correlation between pollutants their sources and management practices. The features of buildings I, II, and III are old infrastructure, new modern infrastructure, and an old building with good maintenance. The results indicate that the average concentrations of PM10, PM2.5, and PM1 are found in the range of 55-150 ?g m-3, 41-104 ?g m-3 and 37-95 ?g m-3, respectively in Building I, 33-136 ?g m-3, 30-84 ?g m-3 and 28-73 ?g m-3, respectively in Building II and 216-330 ?g m-3, 188-268 ?g m-3 and 171-237 ?g m-3, respectively in Building III. The maximum proportion of the total mass contributed by PM0.25-1.0 i.e., up to 75%, 86%, and 76% in the meeting room of Building I, II and III, respectively. The proportion of ultrafine particles was found higher in the office area where the movement was minimum and vice versa. The higher I/O indicates the contribution of the presence of indoor sources for ultra-fine and finer particles. Further, possible strategies for indoor air pollution control are also discussed.