Daniela S. Nitiu

Quantitative aeropalynology in the atmosphere of Buenos Aires city, Argentina

For the first time, a volumetric study ofBuenos Aires city atmosphere was conductedusing a Lanzoni collector from March 1997through March 1998. Fifty-four pollen typeswere recorded of which 13 had a relativeconcentration of more than 1% of the yearlytotal. The lowest concentration of pollengrains was recorded in June, when Urticas,pp., Morus spp., and Myrtaceae were low.On the other hand, the highest concentration ofpollen grains was reached in September, with anincrease in Fraxinus spp. Theaeropalynological record may be divided intothree periods: *AP Dominant from July toOctober, *NAP Dominant from November toMarch, and *Residual Period from April toJune with low pollen concentrations.The greatest number of species was recorded inNovember, when 32 types were present, and thelowest number of species in June, when only 13pollen types were recorded. In June, the pollenconcentration was not dominated by any specieswhereas in September 85% of the pollen wasderived from one species of Fraxinus.Earlier studies on the aeropalynology of BuenosAires City were performed using Tauber andRotorod samplers. They were comparable to thisstudy, especially since the pollen peak wasreached in September, although the main pollenproducing species were different.

Annual, daily and intradiurnal variation of Celtis pollen in the city of La Plata, Argentina

The behaviour of Celtis airborne pollenwas studied for a period of three years(1998–2000) in the city of La Plata. The pollengrains were captured with a Lanzoni trap andthe maximum pollination period was observed tooccur during the end of winter and spring inthe three years. The annual values of pollenconcentration varied, and a significantdecrease was observed during 2000. The greatestairborne pollen record was in October with anaverage of 82.3% in relation to its totalconcentration during 1998–2000. Based on theintradiurnal behaviour analysis, it wasobserved that the maximum pollination peakoccurs at 2H when the temperaturereaches its maximum values. Considering thethree sampling years, the meteorologicalvariables that most influenced the processes of pollen emission,dispersion and transportation in the atmospherewere: maximum and minimum temperature andrainfall.

Intradiurnal fluctuation of pollen in La Plata, Argentina. Part I, herbaceous pollen types

A pollen analysis was carried out on six herbaceous pollen types whose annual concentration represents a percentage higher than 0.3% in the atmosphere of the city of La Plata, Argentina, from July 1998 to June 2001. They are: Ambrosia, Cyperaceae, Chenopodiaceae-Amaranthaceae, Plantago, Poaceae and Urticaceae. Hourly patterns of the pollen types analysed with the intradiurnal daily index (IDI) could be grouped into three categories account the percentage that represent of pollen concentration registered during five hourly periods of the day. Group I includes pollen types that show a sharp peak in abundance gust one at hour of the day. Group II is formed by pollen types that show high concentrations in more than one hourly band during the daylight. Group III is characterized by the pollen types that show lower concentrations over a broad hourly band during the day.

Fungal monitoring of the indoor air of the Museo de La Plata Herbarium, Argentina

BACKGROUND Biological agents, such as fungal spores in the air in places where scientific collections are stored, can attack and deteriorate them. AIMS The aim of this study was to gather information on the indoor air quality of the Herbarium of Vascular Plants of the Museo de Ciencias Naturales de La Plata, Argentina, in relation to fungal propagules and inert particles. METHODS This study was made using a volumetric system and two complementary sampling methods: (1) a non-viable method for direct evaluation, and (2) a viable method by culture for viable fungal propagules. RESULTS The non-viable method led to ten spore morphotypes being found from related fungal sources. A total of 4401.88spores/m3 and 32135.18 inert suspended particles/m3 were recorded. The viable method led to the finding of nine fungal taxa as viable spores that mostly belonged to anamorphic forms of Ascomycota, although the pigmented yeast Rhodotorula F.C. Harrison (Basidiomycota) was also found. A total count of 40,500fungal CFU/m3 air was estimated for all the sites sampled. CONCLUSIONS Both the non-viable and viable sampling methods were necessary to monitor the bio-aerosol load in the La Plata Herbarium. The indoor air of this institution seems to be reasonably adequate for the conservation of vascular plants due to the low indoor/outdoor index, low concentrations of air spores, and/or lack of indicators of moisture problems.