Trends and threshold exceedances analysis of airborne pollen concentrations in Metropolitan Santiago Chile

Pollen is one of the primary causes of allergic rhinoconjunctivitis in urban centers. In the present study, the concentrations of 39 different pollens in the Santiago de Chile metropolitan area over the period 2009–2013 are characterized. The pollen was monitored daily using Burkard volumetric equipment. The contribution of each type of pollen and the corresponding time trends are evaluated. The concentrations of the pollens are compared with the established threshold levels for the protection of human health. The results show that the total amount of pollen grains originating from trees, grasses, weeds and indeterminate sources throughout the period of the study was 258,496 grains m-3, with an annual average of 51,699 ± 3,906 grains m-3 year-1. The primary source of pollen is Platanus orientalis, which produces 61.8% of the analyzed pollen. Grass pollen is the third primary component of the analyzed pollen, with a contribution of 5.82%. Among the weeds, the presence of Urticacea (3.74%) is remarkable. The pollination pattern of the trees is monophasic, and the grasses have a biphasic pattern. The trends indicate that the total pollen and tree pollen do not present a time trend that is statistically significant throughout the period of the study, whereas the grass pollen and weed pollen concentrations in the environment present a statistically significant decreasing trend. The cause of this decrease is unclear. The pollen load has doubled over the past decade. When the observed concentrations of the pollens were compared with the corresponding threshold levels, the results indicated that over the period of the study, the pollen concentrations were at moderate, high and very high levels for an average of 293 days per year. Systematic counts of the pollen grains are an essential method for diagnosing and treating patients with pollinosis and for developing forestation and urban planning strategies.     

Airborne fungi monitoring in Santiago, Chile

Fungal airborne spores were studied from September 1996throughout August 1997 in Santiago, Chile. Total concentrationsfluctuated between 308 and 10,334 spores/m³/day withan annual mean of 2,154 per m³, the highest dispersion beingduring April and May. Forty-five percent of total fungal content wasfound in autumn. Thirteen genera and 3 other spore types wereidentified. Cladosporium, the most abundant genera in ouratmosphere, contributed with 70.9% of the total fungi counts andreached an annual mean of 1,527 spores/m³/day, itshighest frequency being in autumn. Alternaria appeared as thesecond most frequent genera, with an annual mean of 40spores/m³/day, representing a 1.9% of theannual fungal catch. Altogether, Stemphylium, Torula, Epicoccum,Ganoderma, Helminthosporium, Chaetomiun, Pleospora and othersreached relative frequencies of 0.5% or less. It is concludedthat fungi are present in Santiago's atmosphere all year round, some ofthem with a clear seasonality.     

Dermatophyte infection and colonization in dogs from South Santiago, Chile

Our main aim was to determine the dermatophyte infection and colonization prevalence in canines from South Santiago, Chile. We studied 241 dogs, 121 of them presented cutaneous lesions suggestive of dermatophytosis and the other 120 were free from lesions and were considered clinically healthy. Dermatophytes were isolated from the lesions of 48.8% of animals with cutaneous diseases and from 5% of healthy dogs. Microsporum canis was the principal species isolated with a frequency of 98.3% from dermatophytosis and from all healthy carriers. The direct microscopic test showed a sensibility of 85% with a positive and negative predictive value of 74 and 79%, respectively. The highest prevalence of dermatophytosis were detected in animals up to one year old (p <= 0.05) and in dogs with high level of irritation, scaly skin, itching and alopecia (p < or = 0.05). The lesions were detected more frequently in head-neck and anterior members (p < or = 0.05). This study shows some clinical characteristics and a frequency of dermatophytes in canines that can be interesting for laboratory professionals and veterinarians.     

A study of histocompatibility-2 antigens in wild mice from Santiago,Chile

LyM-1 is the provisional designation given to a system of murine cell-surface alloantigens which are controlled by genes closely linked to those of theMls system. Formal genetic analysis has failed to disclose separation of genes determiningMls and LyM-1 antigens, but studies of the distribution of these antigens among inbred strains shows that the LyM-1 polymorphism is not primarily responsible for the MLR activity associated with Mls differences, and suggests that LyM-1 and Mls substances are products of genes at closely linked, but probably separate loci. Absorption analysis shows that strains whose cells react with anti-LyM-1.2 can be divided into at least two classes on the basis of the efficiency with which their cells remove anti-LyM-1.2 antibodies. This provides evidence for the existence of two LyM-1 alleles in addition to the one(s) possessed by nonreactive mouse strains.     

Indicators for sustainable land use management in Santiago de Chile

Indicators are helpful tools for land use management; especially in the context of sustainable urban development, they are indispensable information bases for decision making, communication, and awareness rising. For Santiago de Chile, like many other large and dynamic cities, a high complexity of geographical conditions, social and land use pattern, diverging interests, and a high velocity of development are characteristic. In this situation, the Risk Habitat Megacity (RHM) initiative seeks to support local and regional authorities in elaborating indicators applicable in land use and flood risk management.In this article, the indicator approach of the Land Use Management group within the RHM initiative is presented. Based on the analysis of characteristics of and demands on sustainability indicators, existing indicator sets for Santiago de Chile are analysed. Thereafter, the indicator set for sustainable land use management in Santiago de Chile is presented. It was elaborated in a combined bottom–up and top–down approach in discussion with Chilean scientists and stakeholders in order to guarantee its relevancy to practice. The analysis of the already existing indicators in Santiago de Chile shows that the newly developed toolset forms a valuable and complementary addition, mainly for two reasons: the interdisciplinary nature of the set and its reproducibility.     

Incidence of infection by intestinal parasites among school children in Santiago, Chile, 1988-1989

In December 1988-February 1989 period, a survey on enteroparasitic infections in children (mean age 8.7 years; males 54.4% and females 45.6%) from five schools located in Santiago, Chile, was undertaken. To each of these individuals, three samples were obtained in order to perform in them the following examinations: co-proparasitological study, modified Ziehl-Neelsen staining for detecting Cryptosporidium sp. and cellulose adhesive test for Enterobius vermicularis. Parasitic elements were found in the following percentages: Blastocystis hominis 51.8, Enterobius vermicularis 39.9, Giardia lamblia 32.1, Entamoeba histolytica 7.8, Hymenolepis nana 2.1 and Ascaris lumbricoides 0.4, Cryptosporidium sp. were not observed. The present study would be demonstrating that enteroparasites maintain their endemic condition among school children from Santiago, including B. hominis which had not been searched previously.