Air pollutants and meteorological variables largely influence pollen concentration and they cause widespread upper respiratory tract and naso-bronchial allergy with manifestations like asthma, seasonal rhinitis, and bronchial irritation. A study conducted in Chandigarh by Prof. Ravindra Khaiwal from the Post Graduate Institute of Medical Education and Research (PGIMER), along with Dr. Suman Mor, Chairperson, Department of Environment Studies and Akshi Goyal, a Ph.D. research scholar, found that air pollutants influence pollen concentration and different types of pollen have a unique response to weather conditions. The study, published in Science of the Total Environment, is reportedly one of the first studies in India trying to understand the impact of air pollutants and meteorological variables in airborne pollen. The researchers expressed hopes for further research in this domain to explore how specifically the urban environment significantly impacts plant biological and phenological parameters.