Polen atmosférico de importancia alergológica en el área metropolitana de Monterrey (Nuevo León, México), durante el periodo Marzo 2003-Febrero 2005

the amount of atmospheric pollen of allergological concern was monitored in the metropolitan area of monterrey during the period from march 2003 to february 2005. pollen collection was made using a hirst type trap (burkard manufacturing co. ltd., rickmansworth, uk) placed 15 m above the ground over the top of two buildings. the total count registered during the sampling period was 68 962 grains. the months of maximum pollen incidence were february and march 2004 with 13 225 and 10 384 grains respectively. the average monthly value was 2 873 grains. taxa of major occurrence and perhaps of main allergological concern for the metropolitan area of monterrey were fraxinus sp (14 312 grains), cupressaceae-taxodiaceae (12 448 grains), parietaria pensylvanica (12 354 grains) poaceae (4 808 grains), celtis sp (3 153 grains), moraceae (1 806 grains), pinus sp with 2 693 grains, ambrosia confertiflora (2 132 grains), ricinus communis with 1 697 grains, amaranthaceae-chenopodiaceae (1 691 grains), quercus sp (1 360 grains), prosopis sp (1 227 grains), platanus occidentalis (725 grains) and carya sp with 687 grains.