title: Associations between pollen counts, pollutants, and asthma-related hospital admissions in a high-density Indian metropolis.
abstract: BACKGROUND
  The seasonal pattern of asthma-related hospitalization has often been correlated with ambient allergen/pollutant levels.
  
  
  OBJECTIVE
  To examine the relationship between asthma-related hospital admissions (ARHA) and outdoor pollen, spore, and pollutant levels for adult patients in a densely populated Indian megacity Kolkata.
  
  
  METHODS
  ARHA data were obtained from two major teaching hospitals of the city. Pollen and spores causing allergic sensitization were identified by skin prick tests (SPTs) among respiratory allergic subjects (N = 1353). Outdoor concentrations of aeroallergens were determined using a Burkard sampler for five consecutive years (2004-2009). Levels of NO(2), SO(2), suspended particulate matters (SPMs), and respirable particulate matters (RPMs) were made available by West Bengal Pollution Control Board (WBPCB, Government of West Bengal). Poisson multivariate Poisson regression (with adjustments for overdispersion) was used to model the data. Results. We found that ARHA in Kolkata increased with predictable regularity in March and September, while remaining low in January and July. SPT showed highly positive skin reactions with grass/weed and palm pollens in respiratory allergic patients, while Aspergilli spores also evoked good sensitivity. In our regression model, the airborne pollen types, Cheno-Amaranthaceae and Cyperaceae, and the inorganic pollutant, SO(2) and RPM, were significantly associated with ARHA (p < .05).
  
  
  CONCLUSIONS
  ARHA in the megacity of Kolkata shows two seasonal peaks that can be correlated with outdoor grass/weed pollen and RPM concentrations. In contrast, the city's ambient fungal spore counts were not found to be significantly associated.
authors.affiliation: Division of Plant Biology, Bose Institute, Kolkata, India. debajyoti.ghosh@uc.edu
authors.forename: D
authors.initials: D
authors.lastname: Ghosh
authors.forename: P
authors.initials: P
authors.lastname: Chakraborty
authors.forename: J
authors.initials: J
authors.lastname: Gupta
authors.forename: A
authors.initials: A
authors.lastname: Biswas
authors.forename: I
authors.initials: I
authors.lastname: Roy
authors.forename: S
authors.initials: S
authors.lastname: Das
authors.forename: S
authors.initials: S
authors.lastname: Gupta-Bhattacharya
mesh_terms: D000328:Adult; D000393:Air Pollutants / Q000032:analysis / Q000276:immunology*; D000485:Allergens / Q000032:analysis / Q000276:immunology*; D001249:Asthma / Q000276:immunology*; D016022:Case-Control Studies; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D007194:India; D008297:Male; D011058:Pollen / Q000276:immunology*; D012044:Regression Analysis; D012621:Seasons; D013170:Spores / Q000276:immunology*; D014505:Urban Population
chemical_list: D000393:Air Pollutants; D000485:Allergens