Airborne Algae Research Articles

Study on the deterioration of mortar by enteromorpha-diatoms during green tide

Similar to the deterioration of construction materials by airborne algae, hydrophytic algae can deteriorate cementitious materials and change the performance of structures, thereby reducing the safety and economics of marine facilities. Frequent outbreaks of green tides have occurred in recent years, and algae have been shown to deteriorate calcium substances in cementitious materials. Therefore, the pattern of deterioration of cement by algae as a result of green tide outbreaks is important for extending the durability of marine installations. For this reason, the dominant species of the green tide outbreak, Enteromorpha, and the marine primary producer, diatoms, were selected to simulate the green tide outbreak in this paper. Then, in the paper, the colonization law of Enteromorpha and diatom and the calcium loss law in mortar are discussed. Results showed four stages of Enteromorpha-diatoms colonization on the mortar surface (diatoms colonization within 15 days, release of spores from Enteromorpha, germination of spores from Enteromorpha within 60 days, and transformation of the relationship between the colonization of Enteromorpha and diatoms). Three channels for the loss of calcium on the surface of the mortar include the uptake and transformation, the complexation of biofilm, and the dissolution and deposition. Additionally, Enteromorpha-diatoms can deteriorate the mortar surface, mineral composition, and microstructure.

Will "Air Eutrophication" Increase the Risk of Ecological Threat to Public Health?

Aquatic eutrophication, often with anthropogenic causes, facilitates blooms of cyanobacteria including cyanotoxin producing species, which profoundly impact aquatic ecosystems and human health. An emerging concern is that aquatic eutrophication may interact with other environmental changes and thereby lead to unexpected cascading effects on terrestrial systems. Here, we synthesize recent evidence showing the possibility that accelerating eutrophication will spill over from aquatic ecosystems to the atmosphere via "air eutrophication", a novel concept that refers to a process promoting the growth of airborne algae, some of them with the capacity to produce toxic compounds for humans and other organisms. Being catalyzed by various anthropogenic forcings─including aquatic eutrophication, climate warming, air contamination, and artificial light at night─accelerated air eutrophication may be expected in the future, posing a potentially increasing risk of threat to public health and the environment. So far knowledge of this topic is sparse, and we therefore consider air eutrophication a potentially important research field and propose an agenda of cross-discipline research. As a contribution, we have calculated a tolerable daily intake of 17 ng m-3 day-1 for the nasal intake of microcystins by humans.

Airborne Algae: A Rising Public Health Risk.

ADVERTISEMENT RETURN TO ARTICLES ASAPPREVViewpointNEXTAirborne Algae: A Rising Public Health RiskMickey M. Rogers*Mickey M. RogersEnvironmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99354, United States*[email protected]More by Mickey M. RogersView Biographyhttps://orcid.org/0000-0002-9082-119X and Robert K. StanleyRobert K. StanleyEnvironmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99354, United StatesMore by Robert K. Stanleyhttps://orcid.org/0000-0002-2133-9906Cite this: Environ. Sci. Technol. 2023, XXXX, XXX, XXX-XXXPublication Date (Web):March 30, 2023Publication History Received10 February 2023Published online30 March 2023https://doi.org/10.1021/acs.est.3c01158Not subject to U.S. Copyright. Published 2023 by American Chemical SocietyRIGHTS & PERMISSIONSArticle Views-Altmetric-Citations-LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (2 MB) Get e-AlertsSUBJECTS:Aerosols,Anatomy,Environmental chemistry,Toxins,Wind Get e-Alerts

Quantitative and qualitative variability of airborne cyanobacteria and microalgae and their toxins in the coastal zone of the Baltic Sea

Apart from viruses and bacteria, cyanobacteria and microalgae present in the atmosphere may pose a threat to the health of humans by inducing illnesses and diseases. Yet, they play an important role in the environment, influencing the Earth's radiation budget by absorbing and scattering solar radiation. The present study determined the daily and seasonal qualitative and qualitative variabilities of airborne cyanobacteria and microalgae during both vegetative and non-vegetative seasons in the coastal zone of the Baltic Sea. Samples were collected from January to December 2020 with a Tisch six-stage microbiological impactor which was used as a substitute for the respiratory tract. The stage levels of the impactor represented the respiratory tract and reproduced lung penetration by airborne particles, which allowed us to assess penetration of cyanobacteria and microalgae to the deepest parts of the human respiratory system. A total of 296 samples of cyanobacteria and microalgae were collected during the day and 276 samples during the night. The results showed that cyanobacteria and microalgae were present in the air all year, and their maximum abundance was 1685 cells m−3 in July. Furthermore, the ability of these microorganisms to produce the toxin microcystin-LR (MC-LR) was confirmed, which has a high potential negative impact on human health. MC-LR has been found in Nostoc sp., Pseudanabaena sp., Leptolyngbya sp., Synechococcus sp., Gloeocapsa sp., Aphanothece sp., and Rivularia sp. maintained at our Culture Collection of Airborne Algae (CCAA), as well as from air samples. The highest concentrations of MC-LR were recorded in airborne Synechococcus sp. CCAA 46 and amounted to as much as 420 fg cell−1. In turn, the highest mean concentration of 0.95 μg L−1 for MC-LR was recorded in an air sample taken in May. This research expands the knowledge on cyanobacteria and microalgae present in the atmosphere in the coastal zone of the southern Baltic Sea. We propose these microorganisms be used as indicators for further research on bioaerosols, which are potentially dangerous to human health.

Study on the occurrence and evaluation index of soiling caused by airborne algae on exterior walls

Study on the occurrence and evaluation index of soiling caused by airborne algae on exterior walls

Enlisting Aero-algal Flora and Algal Allergens Using Fan Dust Sampling Method from Pune, Maharashtra

Algae in the atmosphere are one of the bio-components of the environment. Despite the fact that they may have a negative impact on human health, they are the least studied organism in the field of aerobiology. Airborne algae continue to be viable in the atmosphere in the form of spores and filaments. In order to investigate the intramural diversity of airborne algae in Pune, eight residences were chosen, from which 16 fan dust samples were collected over a ten-day period. Total (108) aero-algal forms were recorded. Out of which 107 were Cyanophyta, and only one was Chlorophyta. The dominance of Cyanophyta members is attributed to the presence of a thick mucilaginous sheath around them, which allows them to tolerate the dryness. Overall, filamentous cyanophytes (71) outnumber coccoid cyanophytes (36). However, both fan dust slide samples and culture slide samples show variance. Coccoid cyanophytes (53) outnumber filamentous cyanophytes (11) in direct slide scans, although filamentous cyanophytes (25) were somewhat more numerous in culture samples than coccoid Cyanophyta (19). This increase in filamentous forms might be because of hormogonia of filamentous algae, which remained unidentified in direct slide scan and upon inoculation underwent reproduction increasing number of filamentous algae in culture slides. Chrooccocus, Gloeocapsa, Lyngbya, Nostoc, and Stigonema were among the forms found on the first and tenth days of fan dust sampling, indicating that they were a common inhabitant of fan dust during the study and that the fan, as an aero sampler, was able to capture them, demonstrating its potency as an aero sampler. Soil can be a substantial factor in the creation of fan dust, as these genera were frequently separated from the soil. Gloeocapsa, Phormidium, Lyngbya, Schizothrix, Cylindrospermum, Nostoc, Anabaena, Scytonema, Calothrix, and Scenedesmus were among the allergic aero-algal genera discovered during the investigation.

Bio-diesel production from airborne algae

Airborne algae are spread in the environment by various local air movements. Some airborne algal species are exceptionally tolerant and adaptive to variable climatic conditions and may also be dispersed over long distances. Such species are more likely to be better sustained in open culture systems. To test this hypothesis, this study collected airborne algal samples throughout the year (2014–2015) monthly from a campus setting in Odisha, India, and then cultured, transesterified and characterized them. The post-monsoon season (i.e., the months of October, followed by November, September, December, and August) was the most favorable climate for the occurrence of airborne algal species from the Chlorophyta domain and was having a higher growth rate. Accumulation of higher iron content within the algal cell was detected by atomic absorption spectrometer (AAS) compared to other trace metals. Samples from October were found to contain higher lipid content (~30%) among all collected samples. GC–MS detected the higher oleic acid (C18:1) and palmitic acid (C16:0) in fatty acid methyl ester (FAME) content. Similarly, high-performance liquid chromatography (HPLC) of methanol layer data reveals the presence of maltotriose, arabinose, cellobiose, glucose, xylose, inulin, and stachyose.

Toxic or Otherwise Harmful Algae and the Built Environment.

This article gives a comprehensive overview on potentially harmful algae occurring in the built environment. Man-made structures provide diverse habitats where algae can grow, mainly aerophytic in nature. Literature reveals that algae that is potentially harmful to humans do occur in the anthropogenic environment in the air, on surfaces or in water bodies. Algae may negatively affect humans in different ways: they may be toxic, allergenic and pathogenic to humans or attack human structures. Toxin-producing alga are represented in the built environment mainly by blue green algae (Cyanoprokaryota). In special occasions, other toxic algae may also be involved. Green algae (Chlorophyta) found airborne or growing on manmade surfaces may be allergenic whereas Cyanoprokaryota and other forms may not only be toxic but also allergenic. Pathogenicity is found only in a special group of algae, especially in the genus Prototheca. In addition, rare cases with infections due to algae with green chloroplasts are reported. Algal action may be involved in the biodeterioration of buildings and works of art, which is still discussed controversially. Whereas in many cases the disfigurement of surfaces and even the corrosion of materials is encountered, in other cases a protective effect on the materials is reported. A comprehensive list of 79 taxa of potentially harmful, airborne algae supplemented with their counterparts occurring in the built environment, is given. Due to global climate change, it is not unlikely that the built environment will suffer from more and higher amounts of harmful algal species in the future. Therefore, intensified research in composition, ecophysiology and development of algal growth in the built environment is indicated.

The Effect of Abiotic Factors on Abundance and Photosynthetic Performance of Airborne Cyanobacteria and Microalgae Isolated from the Southern Baltic Sea Region.

Cyanobacteria and microalgae present in the aquatic or terrestrial environment may be emitted into the air and transported along with air masses over long distances. As a result of staying in the atmosphere, these organisms may develop a greater tolerance to stressful factors, but this topic is still relatively unknown. The main aim was to show an autecological characteristic of some airborne microalgae and cyanobacteria strains by a factorial laboratory experiment approach, including changes in irradiance, temperature, and salinity conditions. The additional purpose of this work was also to present part of the Culture Collection of Baltic Algae (CCBA) collection, which consists of airborne algae (AA) isolated from the atmospheric air of the southern Baltic Sea region. Altogether, 61 strains of airborne cyanobacteria and microalgae from the southern Baltic Sea region were isolated from May 2018 to August 2020. Selected microorganisms were tested in controlled laboratory conditions to identify their response to different irradiance (10–190 µmol photons m−2 s−1), temperature (13–23 °C), and salinity conditions (0–36 PSU). The highest numbers of cells (above 30 × 105 cell mL−1) were recorded for cyanobacterium Nostoc sp., and for diatoms Nitzschia sp., Amphora sp., and Halamphora sp. We found that for cyanobacterium Nostoc sp. as well as for green alga Coccomyxa sp. the maximum cell concentrations were recorded at the salinity of 0 PSU. Moreover, cyanobacteria Planktolyngbya contorta, Pseudanabaena catenata, Leptolyngbya foveolarum, Gloeocapsa sp., and Rivularia sp. were able to grow only at a salinity of 0 PSU. On the other hand, in the range of 16–24 PSU, the highest cell numbers of examined diatoms have been identified. Our research provided that deposited airborne microalgae and cyanobacteria showed full colonization potential. The present experiment suggests that the adaptive abilities of microorganisms, in particular those producing toxins, may contribute to the spread in the future. Thus, it may increase human exposure to their negative health effects. Any distinctive adaptations of the genera give them an additional competitive advantage and a greater chance for territorial expansion.

Airborne Algal growth on roofs of membrane-structured residences in cold area of Japan

The discoloration of building facades due to airborne algae is observed in our surroundings. The growth conditions of these algae are not yet fully understood, and efficient measures for preventing the growth of the algae are not presently available. The objective of this study was to investigate the effects of the ambient environment and building structure on algal growth. A residential building in a cold region of Japan was surveyed. The roof was a multi-layered structure comprising a semi-transparent film, an air layer, and a layer of insulation from the outside, supported by rafters. The soiled state was visually observed by taking photographs. On the northeast (NE) and northwest (NW) roofs, several black stripes appeared 4 months after cleaning. The soiling increased in the spring and autumn. The soiling first appeared on the film backed by the rafter and then extended to the film backed by the air layer. The condensation time during the day in the rafter part was longer than that in the air-layer part. Condensation occurred during the night, but its frequency exhibited no dependence on the orientation of the roof. Algae tend to die when exposed to an environment with a temperature higher than 45°C. The NE roof had the shortest period with a surface temperature of >45°C. These measurements agreed well with the survey results, which indicated that the soiling mainly occurred on the NE and NW sides of the roofs. The time for algal growth was estimated under the assumption that algae can grow at surface temperatures ranging from 0 to 45°C, in agreement with the observed soiling. The observed soiling changes were well explained by the algal population calculated via a growth predictive model according to the algal temperature and relative humidity.

Measurement of airborne algal mortality rates due to heat shock treatment

Green and/or black soiling on building facades worldwide is caused by airborne algae, which has strong drought tolerance and grows in the atmosphere. Poikilohydric plants such as algae and lichens have high heat resistance under dry conditions and high thermo-sensitivity under wet conditions. However, there have been no studies of heat shock treatments against airborne algae adhering to surfaces. This study investigated the relationship between heat shock conditions (treatment temperature and duration and the water content of algae) and algal mortality. Algae collected from the exterior wall of a building were heat-treated in a laboratory, and their chlorophyll fluorescence intensity was measured. The following results were obtained: (a) higher treatment temperature and longer treatment time increased the rate of algal death, (b) the survival rate of heat-treated dry algae was higher than that of wet algae and recovered after the treatment, and (c) the effects of continuous and intermittent heat shock were similar, and algal mortality increased with the total treatment time. It was concluded that the airborne algae died after heat shock treatment at 35 °C for 24 h and at 40 °C after 6 h under wet conditions. Algae from an exterior concrete wall were heat-treated in a wet condition, and algal death was confirmed by the decrease in surface L* values and a color change from green to yellow.

Seasonality of tropical airborne algae: a 16-month study based on high-throughput sequencing in the Hawaiian Islands

The airborne environment is a critical juncture linking terrestrial and aquatic habitats, yet the algae of this environment are not well-characterised and understood. The goal of this study was to examine seasonality patterns of airborne algae in a tropical environment. Airborne algae were collected monthly in spore traps on a building rooftop on the island of Oʻahu, Hawaiʻi, U.S.A. from December 2015 to March 2017. Metabarcoding of Universal Plastid Amplicon (UPA) and 16S ribosomal RNA (rRNA) markers was used to characterise the algal diversity in the samples relative to meteorological data. Modelled back-trajectories of air masses arriving at the site demonstrated that months with the highest rainfall corresponded to those with the strongest tradewind signal. Thirty airborne algal Exact Sequence Variant (ESV)s were identified using the UPA marker including Cyanobacteria (20), Chlorophyta (4), Streptophyta (3), Chrysophyceae (1), Synurophyceae (1), and unknown Stramenopila (1). Forty-four ESVs were identified using the 16S marker and consisted of Cyanobacteria (43) and plastids of Streptophyta (1). The number and diversity of sequence reads obtained varied strongly both among samples for a given time period and from month to month. Highest rainfall and air temperatures corresponded to months with the largest cyanobacterial relative abundance according to the UPA marker. Although cyanobacteria were the most common group identified using the 16S marker, the dominant cyanobacterial taxon varied by month. Diversity or abundance patterns were not explained by meteorological conditions, which may be due to the relatively small annual amplitude in conditions in the Hawaiian Islands.

Field survey of the relationship between environmental conditions and algal growth on exterior walls

Building facades often become black and/or green because of soiling caused by airborne algae. The algal growth is influenced by available water supply including rain, condensation, and water vapor. The influence of other environmental factors, such as solar radiation, temperature, and relative humidity, on algal growth has not been quantitatively investigated. This study aimed to quantify the relationship between wall surface algal growth and environmental conditions.To identify sites where algal soiling is likely to occur, a field survey of soiling was conducted on building facades in Kyoto, Japan. Soiled areas were divided into two classes depending on the source of moisture contributing to algal growth. The algae were identified by the observation of soiling by microscopy.In addition, to clarify the relationship between algal growth and environmental factors, soiling, temperature, and humidity were measured at Kusyo Myojin Shrine, Ninna-ji Temple, Kyoto. Algal growth was influenced by local microclimates, with a strong correlation between algal growth and death with ambient temperature and humidity. For example, algae grew under conditions of high ambient humidity at the shrine. However, parts of the walls exposed to direct solar radiation were not discolored because the algae were more likely to die at high temperatures. Based on these measurements, a predictive model was proposed to calculate the population of algae using the solar radiation, temperature, and humidity as inputs. This model could reproduce the observed trend of wall surface brightness of algal soiling.

Diurnal patterns of airborne algae in the Hawaiian Islands: a preliminary study

Although the literature on the diversity of airborne algal communities in various locations around the world is increasing, little is known about their temporal and spatial patterns. We compared airborne algal communities from Honolulu, Hawai‘i, USA, over three 24-h sampling periods to examine diurnal patterns in diversity and abundance. Using a culture-based approach, 192 algal colonies were characterized and identified as 31 operational taxonomic units. A combination of microscopy and Sanger sequencing (of the UPA marker) was used for characterizations. More airborne algal colonies were identified from nighttime collections (127 of 192 colonies) than daytime collections (65 of 192 colonies) (p < 0.0001). Similarly, 95% of the daytime collections were Cyanobacteria, and 87% of the nighttime collections were Chlorophyta, and the trends of more Cyanobacteria being collected during the day and more Chlorophyta at night were significant (p < 0.0001). Meteorological analyses for the sampling periods indicated that air masses sampled during the three trials consistently arrived in the Hawaiian Islands on a northeast trade wind pattern, but with different origins in the Pacific Ocean, and that low-to-trace levels of rain fell during the sampling periods. Land breeze and sea breeze effects, which are common temperature-driven phenomena on tropical islands, may have played a role in the diurnal pattern observed in the current study.

A metabarcoding comparison of windward and leeward airborne algal diversity across the Ko'olau mountain range on the island of O'ahu, Hawai'i1.

Airborne algae from sites on the windward (n=3) and leeward (n=3) sides of the Ko'olau Mountain range of O'ahu, Hawai'i, were sampled for a 16 d period during January and February 2015 using passive collection devices and were characterized using Illumina MiSeq sequencing of the universal plastid amplicon marker. Amplicons were assigned to 3,023 operational taxonomic units (OTUs), which included 1,189 cyanobacteria, 1,009 heterotrophic bacteria, and 304 Eukaryota (of which 284 were algae and land plants). Analyses demonstrated substantially more OTUs at windward than leeward O'ahu sites during the sampling period. Removal of nonalgal OTUs revealed a greater number of algal reads recovered from windward (839,853) than leeward sites (355,387), with the majority of these being cyanobacteria. The 1,234 total algal OTUs included cyanobacteria, diatoms, cryptophytes, brown algae, chlorophyte green algae, and charophyte green algae. A total of 208 algal OTUs were identified from leeward side samplers (including OTUs in common among samplers) and 1,995 algal OTUs were identified from windward samplers. Barcoding analyses of the most abundant algal OTUs indicated that very few were shared between the windward and leeward sides of the Ko'olau Mountains, highlighting the localized scale at which these airborne algae communities differ. Back trajectories of air masses arriving on O'ahu during the sampling period were calculated using the NOAA HY-SPLIT model and suggested that the sampling period was composed of three large-scale meteorological events, indicating a diversity of potential sources of airborne algae outside of the Hawaiian Islands.

Relationship between Environmental Conditions and Algal Growth on the Exterior Walls of the Ninna-ji Temple, Kyoto

We can find that many building facades are discoloured black and/or green. Some previous studies showed that the soiling of building facades is caused by the growth of airborne algae. The algal growth is strongly influenced by the water supply, including the rain, the condensation, and high humidity. However, the influence of the other environmental factors, such as the solar radiation, the temperature, and the wind on the algal growth, has not been investigated yet. The relationship between the algal growth and the environmental factors on the building facades which the algae grow for long term has not been investigated. Therefore, we quantified the relationship between the algal growth and the environmental factors based on the field survey on the algal growth in Kyoto City and the measurement on the building facades at Kusyo Myojin Shrine, Ninnna-ji Temple in Kyoto, Japan.Kusyo Myojin Shrine was constructed from 1641 to 1647. Some parts of the roof, walls and the painting were repaired from 2004 to 2006. However, the building facades have already been colored black by the algal growth. To investigate the cause of the soiling by the algal growth, the ambient conditions, and surface temperature and humidity of walls were has measured since 2011. The soiling state of the walls was investigated by the L* values and the photographs of the walls.As a result, the order of the L* values of the wall surfaces agreed well with the darkness of the photographs. We concluded that the algal growth and death on the wall surface were affected by the surface temperature of the wall.

仁和寺九所明神の外壁における藻類生育と周辺環境との関係

Building facades are often discolored by the airborne algae. The algal growth is strongly influenced by the water supply. In this study, the environmental conditions and the discoloration of walls were measured on the existing building walls on which the algae grew, and the relationship between them was examined. The ambient air humidity was high at the surveyed building mainly because of the topography and trees. Visual evaluations and the L* values of the wall sections that received the direct solar radiation were not discolored because the algae could not grow on wall sections that became high temperatures.

建物外壁における藻類の生育状況に関する研究

Building facades often become black and/or green because of the airborne algae. The algal growth is mainly affected by the water supply, as well as other environmental factors also influence. In this study, we aimed to elucidate the relationship between the algal growth and environmental conditions. We carried out a field survey on the algal growth in Kyoto City. To investigate the factors that algal growth on the wall under the eaves, we calculated wall surface temperature and humidity considering the coupled heat and moisture transfer, and showed a possible relationship between algal death and high temperature and low humidity.

What's in the air? Preliminary analyses of Hawaiian airborne algae and land plant spores reveal a diverse and abundant flora

:The airborne algae of Oahu, Hawaii was studied along a transect crossing from the leeward to the windward side of the Koolau Mountain Range in summer 2013. Algae were collected on agarized medium in petri dishes from a car window as the vehicle drove from Honolulu to Kailua, Oahu, through an elevation gradient of > 360 m and a rainfall gradient of c. 900–3150 mm yr−1. Light microscopy and molecular methods [18S ribosomal (r)RNA gene, 16S rRNA gene, and UPA sequences] were used to characterize a total of 97 operational taxonomic units from the transect. The airborne algal flora of the transect was dominated by cyanobacteria, followed by chlorophycean green algae, diatoms, and ferns and liverworts. This study is the first in Hawaii to incorporate molecular techniques into the identification of airborne algae.

Airborne algae: overview of the current status and its implications on the environment

A diverse variety of microorganisms comprising bacteria, fungi, viruses, protozoa and algae are found in the atmosphere. They have various implications in the environment and on the health aspects in living organisms. The spatial distribution and their prevalence is affected by climatic changes and other natural processes including human activities. Although bacteria, fungi, viruses, protozoa and algae have been well studied, research in the area of airborne algae appears to be limited indicating that airborne algae are the least studied organisms in both aerobiological and phycological research. The main focus in the studies carried out so far include an analysis of diversity of airborne algae in different climatic conditions, at a particular locality or in different geographical regions. Few available studies review the allergenicity of the airborne algae to humans and/or its possible role in the ecosystem(s). Therefore, in this paper, we provide a comprehensive review of research carried out so far on airborne algae and suggest future research directions for fulfilling the existing gaps based on our understanding of the literature in this area of phycological research.