Aerobiology in Latin America: Past, Present, and Future Directions for Atmospheric Pollen Surveillance

1. Introduction

Aerobiology examines the occurrence, transport, and temporal dynamics of biological particles suspended in the atmosphere, including pollen grains, fungal spores, bacteria, and viruses. In clinical and public health contexts, aeropalynology is especially important because inhaled pollen is a major trigger of seasonal allergic rhinitis, conjunctivitis, and asthma exacerbations. Latin America encompasses highly diverse climates and biomes from tropical rainforests and savannas to arid deserts and high-altitude Andean ecosystems creating strong spatial heterogeneity in airborne pollen spectra and seasonality. At the same time, urban greening, ornamental planting, invasive weeds, and climate change can reshape local pollen exposure profiles, often faster than clinical diagnostic panels or immunotherapy extracts are updated [2,3].

Despite clear clinical relevance, aeropalynology programs across Latin America have developed unevenly. Some countries have produced multi-year city series and atlas-type resources, whereas others rely on short campaigns or gravimetric “pollen rain” surveys. In 2023, the Red/Latin American Aerobiology Network (RLA/LAAN) was launched to facilitate collaboration, training, and communication between monitoring groups and clinicians [2]. In parallel, Mexico’s Red Mexicana de Aerobiología (REMA) provides routine, public-facing weekly pollen reports across multiple localities [1].

This review synthesizes the past and present state of aeropalynology in Latin America, emphasizing the dominant pollen taxa reported, the monitoring approaches used, and the degree to which data are translated into actionable products (calendars, thresholds, alerts, and decision support). We further highlight Mexico’s role as a regional reference due to its comparatively extensive datasets and the adoption of emerging computational identification tools. Finally, we propose a roadmap for harmonization and future capacity building across the region.

A schematic timeline of key aeropalynology milestones and network developments in Latin America is summarized in Figure 1.

2. Materials and Methods

This manuscript was prepared as a structured literature review, following PRISMA 2020 guidance for transparent reporting of evidence synthesis [3]. We searched PubMed/MEDLINE, Scopus, Web of Science, SciELO, Google Scholar, and LILACS for articles published up to May 2025. Search terms included combinations of “aerobiology”, “aeropalynology”, “pollen”, “airborne pollen”, “bioaerosols”, “allergic rhinitis”, and “asthma”, paired with country names in English, Spanish, and Portuguese. Reference lists of included articles were also screened to identify additional relevant sources. We additionally included publicly accessible monitoring network resources (e.g., REMA and RLA/LAAN web platforms) to characterize current station capacity and data products.

Inclusion criteria were: (i) original studies, reviews, or technical reports describing aerobiological monitoring in Latin American countries; (ii) studies reporting airborne pollen taxa and/or quantitative indices (counts, calendars, thresholds, season metrics); and/or (iii) studies linking pollen exposure with allergic or respiratory outcomes. We excluded duplicate records, publications without Latin American scope, and records lacking accessible full text or extractable aeropalynology results.

Two-stage screening was performed (title/abstract followed by full-text review). Data were extracted into structured matrices and synthesized narratively by country, emphasizing (a) historical milestones (“past state”), (b) current monitoring capacity and outputs (“present state”), (c) dominant pollen taxa with likely clinical relevance, and (d) translational elements (calendars, public reporting, clinical correlation). Because study designs, sampling methods, and reporting units differed widely, quantitative meta-analysis was not attempted; instead, findings were integrated qualitatively and summarized in tables.

3. Development by Country: Past and Present State

3.1. Argentina

Past state. Argentina hosts one of the oldest and most diverse aeropalynology traditions in Latin America, spanning early gravimetric “pollen rain” surveys and subsequent adoption of volumetric monitoring in major cities. Early multi-year pollen rain monitoring in Buenos Aires provided baseline taxonomic profiles, later complemented by daily volumetric series that enabled higher temporal resolution of atmospheric pollen dynamics [11,12,13,14].

Present state. City level series expanded coverage across climatic regions, including coastal (Mar del Plata), temperate (Bahía Blanca), and inland settings, and supported interannual comparisons of key arboreal and herbaceous pollen taxa. Monitoring has documented recurrent dominance of tree pollen in spring, with Poaceae and major weeds contributing seasonally. An allergenic pollen atlas for Buenos Aires and multi-city surveys highlight the feasibility of national scale characterization; however, harmonization of sampler types, reporting units, and taxonomic resolution remains necessary to strengthen comparability and clinical translation [14,15,16,17,18,19].

3.2. Chile

Past state. Chile’s aeropalynology evolved from early urban series to standardized volumetric monitoring that supported the development of local aeroallergen panels. Multi-year monitoring in Santiago provided one of the earliest systematic urban aeropalynology datasets in the country [20,21].

Present state. In the central southern region, Burkard/Hirst monitoring in Temuco quantified strong seasonal peaks (September–March) dominated by Poaceae and key weeds such as Rumex. In coastal Valparaíso, combined environmental counts and patient sensitization data identified Parietaria as an emerging aeroallergen, illustrating the value of integrating monitoring with clinical investigation. Continued surveillance in Santiago has documented long-term trends and threshold exceedances, highlighting the need to account for local climatic gradients and urban vegetation management [22,23,24].

3.3. Mexico

Past state. Mexico has a longstanding tradition of aerobiological and allergy research, with early adoption of volumetric Hirst-type sampling in large metropolitan areas. Multi-year monitoring in Mexico City enabled the first airborne pollen calendars and quantified relationships between pollen peaks and bioclimatic factors, typically showing winter maxima driven by arboreal taxa (Fraxinus, Cupressaceae/Juniperus, and Alnus) alongside persistent Poaceae and Urticaceae. Additional foundational datasets were generated in Monterrey and other regions, establishing the value of city-level calendars in different ecoregions [4,5,6,7,8,9,10,49,51].

Present state. Mexico now represents the most developed aeropalynological ecosystem in Latin America. REMA provides routine, public-facing weekly pollen reporting and recent updates across nine localities, supporting continuity and risk communication [1]. High-resolution city series remain active, including the 53-month Burkard/Hirst dataset from Toluca, which reported strong tree dominance (Cupressaceae 52.6%) and quantified diurnal patterns and meteorological associations [5,50]. National coverage is strengthened by additional calendars from Monterrey and arid northern regions such as the Sonoran Desert, where Ambrosia and Chenopodiaceae–Amaranthaceae assume greater prominence [7,8]. Importantly, Mexico is also adopting computational approaches for pollen recognition: PollenSense (Mexico City and Monterrey) integrates automated image analysis models with user-facing exposure reporting through the Pollen Wise app, illustrating an emerging pathway from microscopy to digital decision support [49]. Complementary metagenomic work in Mexico City further demonstrates methodological diversification beyond pollen microscopy for characterizing airborne bioaerosols, while maintaining the need for harmonized aeropalynology for comparability across sites [4,5,6,7,8,9,10,49].

3.4. Peru

Past state. Volumetric aeropalynology in Peru was established relatively recently, with Hirst-type monitoring in Lima beginning in 2012. Early series characterized the local pollen spectrum (including Oleaceae, Poaceae, Myrtaceae, and Betulaceae) and provideds the methodological foundation for subsequent studies [25,26].

Present state. Peru’s current evidence base remains concentrated in Lima, where monitoring has expanded to include both pollen and fungal spores and has been linked to clinical sensitization patterns in symptomatic patients. Studies in southern cities documented exposure to Olea europaea and grasses and reported measurable skin-test sensitization. Recent work also suggests locally important taxa such as Tipuana tipu, emphasizing the need for locally adapted diagnostic panels. Comparative studies with other Southern Hemisphere cities illustrate that seasonality can differ markedly even within the same hemisphere, reinforcing the value of local monitoring rather than extrapolation [27,28,29,30].

3.5. Ecuador

Past state. Published aeropalynology from Ecuador is limited compared with Mexico or the Southern Cone, and early clinical studies in the Andes emphasized house dust mites over grass pollen as sensitizers. Aerobiological characterization has often focused on airborne microorganisms in tropical coastal settings [31].

Present state. Recent initiatives include preliminary pollen and fungal monitoring in Samborondón, with Poaceae among the predominant pollen types, and coastal studies measuring airborne bacteria and fungi and their meteorological correlates. Sensitization profiling from Portoviejo demonstrates frequent aeroallergen sensitization in clinical populations, supporting the rationale for expanded pollen surveillance and integration with clinical endpoints [31,32,42].

3.6. Paraguay

Past state. Systematic aeropalynology in Paraguay has been sparse, with limited historical documentation relative to neighboring countries [33].

Present state. One year of volumetric Hirst monitoring in Asunción (2018) identified a diverse pollen spectrum with frequent representation of Cecropia, Poaceae, Urticaceae, Cyperaceae, and Moraceae. Although grasses are a recognized allergenic group, the clinical relevance of some abundant taxa (e.g., Cecropia) remains uncertain, highlighting the need for paired exposure–sensitization studies and multi-year continuity [33].

3.7. Uruguay

Past state. Uruguay’s earliest volumetric pollen monitoring was reported in Montevideo in the early 2000s, demonstrating the feasibility of city-level airborne pollen surveillance in a temperate coastal environment [34].

Present state. Monitoring has not yet consolidated into a continuous national program, but available series documented broad taxonomic diversity and extended seasons (late winter through autumn), with Poaceae typically representing a major contributor. Re-establishing continuous surveillance and harmonized reporting would enable trend analyses and improve clinical utility [34].

3.8. Colombia

Past state. Colombia has historically had limited aerobiology infrastructure, yet early work in Bogotá described allergenic pollens and their clinical relevance in the mid-20th century. Subsequent surveys incorporated both pollen and spores in a neotropical urban environment and motivated the development of local calendars [35,36].

Present state. Recent progress includes open biodiversity-linked datasets such as the Ibagué aeropalinological–aerobiological dataset, which can support local characterization and comparative analyses. Scaling these efforts will require routine volumetric sampling, harmonized taxonomy, and integration with clinical and meteorological datasets to translate exposure into actionable information [37,38,39].

3.9. Venezuela

Past state. Foundational aerobiology in tropical America includes studies from Venezuela describing frequency and periodicity of airborne pollen and spores under high humidity conditions [40].

Present state. These tropical datasets remain informative for interpreting year-round exposure patterns where fungal spores and certain pollen taxa may exhibit sustained presence rather than narrow seasonal peaks. However, the absence of long-term continuous series and permanent monitoring networks limits the ability to generate alerts or assess temporal trends. Establishing sustained surveillance integrated with meteorological data remains a key priority [41].

3.10. Brazil

Past state. Reports of pollinosis in Brazil date to the 1970s, particularly in the South, where grass pollen (notably Lolium multiflorum) has long been recognized as clinically relevant. In much of the country, however, aeropalynology has historically been less systematic than studies of other bioaerosols, and pollen monitoring has often appeared as a secondary component of broader environmental assessments [43].

Present state. Recent work confirms that pollen relevance is highly regional: grass pollen remains central for pollinosis in southern Brazil and cashew pollen is a distinct trigger in parts of the Northeast. Nevertheless, nationwide pollen surveillance remains fragmented and less standardized than fungal monitoring. Available series suggest shifts in Poaceae seasonality that may reflect climate variability, underscoring the need for sustained volumetric networks and linkage with clinical sensitization data [44,45,46].

3.11. Bolivia and Central America/Caribbean: Evidence Gaps

Across Bolivia and several Central American and Caribbean countries, published volumetric aeropalynology remains scarce or absent in the indexed literature. Given the high burden of allergic diseases and the likelihood of near year-round exposure in tropical climates, targeted capacity building, cross-border collaboration, and the incorporation of these settings into regional networks (RLA/LAAN) represent important priorities. Puerto Rico provides an exemplar from the Caribbean where aerobiological studies have emphasized the predominance of fungal spores, illustrating that bioaerosol burdens in humid island environments may not be pollen-dominated [2,47,48]

Current monitoring capacity reported by REMA in Mexico and by RLA/LAAN member stations elsewhere in Latin America is summarized schematically in Figure 2.

4. Cross-Cutting Aeropalynology Findings in Latin America

Across Latin America, the most consistently reported high-impact airborne pollen taxa can be grouped into: (i) urban and peri-urban trees (Cupressaceae/Juniperus, Fraxinus, Platanus, Olea, Alnus, Quercus, Pinaceae); (ii) grasses (Poaceae), often present across seasons and associated with broad sensitization; and (iii) weeds and ruderal taxa (Urticaceae, Chenopodiaceae–Amaranthaceae, Rumex, Ambrosia, Parietaria). Local dominance is strongly shaped by biogeography, altitude, and urban vegetation management, including the planting of introduced ornamentals and the spread of invasive weeds (Table 1) [1,2,5,42].

Where quantitative series exist, pollen seasons typically show pronounced peaks in temperate latitudes (spring for trees and early summer for grasses), whereas tropical and subtropical settings can display extended or multi-modal seasons, often with substantial year-round background levels. These patterns complicate the direct transfer of diagnostic panels or immunotherapy extracts between cities and emphasize the need for locally derived exposure metrics [1,2,42,51,52]..

5. Discussion

Latin American aeropalynology has expanded substantially, but development remains uneven. Countries with long-standing traditions have demonstrated that extended, multi-year series are feasible and can support interannual trend analysis. However, many datasets across the region remain short or discontinuous, limiting the ability to detect climate-driven shifts, assess the impact of changing vegetation, or design robust early-warning systems (Table 2).

Methodological heterogeneity is a central barrier to comparability. Differences in sampler types (gravimetric vs. volumetric; Rotorod vs. Hirst/Burkard), counting rules, taxonomic depth (family vs. genus/species), and reporting units impede synthesis across cities and countries. Adoption of a minimum reporting set (sampler metadata, counting protocols, standardized units, and clear threshold definitions) would enable regional benchmarking and facilitate integration with meteorological modeling.

Translation to health outcomes is another key gap. While multiple studies report dominant taxa, only a subset links exposure metrics with sensitization profiles, symptom burden, health-care utilization, or targeted immunotherapy. Mexico provides a pragmatic example of translation through REMA routine risk communication and city-level calendars, and it is now extending toward computational identification and digital decision support. Similar translational pipelines could be developed elsewhere by pairing monitoring with clinical cohorts and by co-designing outputs with clinicians and patients.

Clinical translation, morphology, and exposure “proxies” in low-station settings. While emerging computational and automated approaches are increasingly discussed, classical pollen morphology remains the indispensable foundation of aerobiology. Accurate morphological identification anchors longitudinal datasets, enables inter-regional comparison, and provides the clinical interpretability required for allergy diagnosis and immunotherapy planning. As emphasized in recent clinician-facing editorials (including the Annals of Allergy, Asthma & Immunology “10 Tips” series), surveillance data are most impactful when they inform real-world practice guiding which aeroallergens are tested, when testing is performed, and how immunotherapy extracts are selected and updated as exposure patterns evolve [53].

A practical challenge for Latin America is that many communities particularly rural, high-altitude, and underserved regions lack sustained station-based monitoring. In such contexts, “pollen proxies” can provide interim decision support: models that combine meteorology (temperature, wind, precipitation), phenology/vegetation patterns (including urban plantings and invasive weeds), land-use, and other open environmental signals to estimate relative exposure risk. Proxies should be framed transparently as estimates rather than counts, and they perform best when calibrated against high-quality morphologic counting from sentinel stations. This blended approach can extend clinical relevance beyond the footprint of existing samplers, supporting patient counseling, timing of therapy, and prioritization of where future stations would yield the greatest public-health benefit (Table 3).

Experience from the historical development of the North American National Allergy Bureau, as summarized in the Journal of Allergy and Clinical Immunology, illustrates that sustained, standardized counting combined with clinician engagement is essential for converting aerobiology from descriptive monitoring into actionable clinical infrastructure [54]..

Finally, climate change and urbanization likely modulate pollen exposure in Latin America through altered flowering phenology, longer seasons, and shifts in dominant taxa, particularly for introduced ornamentals and invasive weeds. Establishing long-term monitoring in representative ecoregions (temperate, tropical, Andean, arid) is essential to quantify these impacts and to inform adaptation strategies.

A practical translational framework from sampling to standardized products, risk communication, and decision support is summarized in Figure 3.

6. Conclusions and Future Directions

Aeropalynology in Latin America is progressing toward greater clinical relevance, but substantial gaps persist in geographic coverage, methodological harmonization, and translation of exposure data into health action. Mexico currently offers the most complete ecosystem, combining multi-site monitoring, public reporting, multiple regional calendars, and emerging computational identification approaches.

Regional priorities include: (i) stabilizing continuous volumetric monitoring in major cities and representative ecoregions; (ii) harmonizing protocols, taxonomy, and reporting metrics; (iii) publishing locally validated pollen calendars and thresholds; (iv) integrating monitoring with meteorological models for forecasting; and (v) expanding digital tools and open data practices through networks such as RLA/LAAN.