Browsing by Author "Athukorala, A."

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Characterization of airborne microplastics in different indoor environments in University of Kelaniya, Sri Lanka-A preliminary study
(Faculty of Science, University of Kelaniya Sri Lanka, 2024) Saumya, R. L. K.; Deeyamulla, M. P.; De Silva, D. S. M.; Athukorala, A.; Bakir, A.; McGoran, A. R.
Airborne microplastic (MP) contamination in indoor environments is an increasing concern due to potential health risks from inhalation. This study examined the distribution, polymer composition, and morphology of airborne MPs in five indoor settings at the University of Kelaniya, Sri Lanka. Passive sampling was conducted over 14 days in one office, two laboratories, and two lecture halls. A diverse array of MP forms and colors were identified using stereomicroscopy and advanced micro imaging. Further analyses were carried out using laser direct infrared spectrometer (LDIR) to identify the constituent polymer types of MPs. Fibers dominated the fallout samples in the office (100%), lecture hall 2 (60%), laboratory 1(56.25%), lecture hall1 (25%), whereas no fibers were found in the sample taken from laboratory 2. However, fragments were identified only in the sample collected from laboratory 2. Films were present at all locations except the office, but their number was relatively lower compared to fibers. The deposition rates of fibers were 3.7 × 102 fibers/m2/day in the laboratory 1, 0.82× 102 fibers/m2/day in the lecture hall 1, 1.23 × 102 fibers/m2/day in the lecture hall 2, and 1.64 × 102 fibers/m2/day in the office. The deposition rates of films in laboratory 1 and the lecture hall 2 were close to each other, corresponding to 1.64 × 102 films/m2/day. Among the selected indoor environments examined in this study, laboratory 1 exhibited the highest deposition rate of MPs on both fibers and films. The increased accumulation is likely due to the proximity of an active construction site, which could facilitate the transport of MPs into the laboratory. Furthermore, the laboratory's heavy use by approximately 60 students daily may have contributed to higher MPs levels. Conversely, laboratory 2 displayed the lowest deposition rate of MPs. This difference can be linked to several factors, including its relatively lower student occupancy, the shorter durations students spend within the laboratory environment and the air-conditioned nature. In all selected indoor environment settings, the prevalent color among MPs is transparent. Laboratory 1 exhibits a relatively balanced representation of transparent (35.29%), green (35.29%) and red (17.69%) MPs, while laboratory 2 predominantly comprises blue (50%) MPs. Lecture hall 1 shows a significant presence of blue MPs (50%), while lecture hall 2 primarily consists of transparent MPs (60%). The office environment exclusively contains transparent MPs. Laboratory 1 and laboratory 2 predominantly have MPs in the 100–250 μm range, while lecture hall 1 and lecture hall 2 show more varied sizes with larger particles being more prevalent, and the office environment mainly contains particles in the 250–500 μm. LDIR spectroscopy was revealed that the MPs were composed of polyamide (17%), polyethylene (10%), polyurethane (7%), polyester (6%), polypropylene (4%), and acrylonitrile butadiene styrene (2%). This study highlights the prevalence of MPs in various indoor environments, emphasizing the importance of evaluating health risks associated with long term exposure.
Microplastic contamination in selected commercial fish species in Negombo Lagoon, Sri Lanka
(Faculty of Science, University of Kelaniya Sri Lanka, 2023) Athukorala, A.; Amarathunga, A. A. D.; De Silva, D. S. M.; Bakir, A.; McGoran, A.; Sivyer, D. B.; De Silva, C. L. C. L.; Narangoda, S. R. C.
Microplastics (MPs) act as physical anthropogenic pollutants and their ability to act as contaminant vectors in biological matrices has become a serious ecosystem and human health concern. The present study, for the first time, has screened and detected MPs in the gastrointestinal tract and gill of a select group of commonly consumed fish species from Negombo lagoon, Sri Lanka. Negombo lagoon is one of the most productive ecosystems in Sri Lanka. A total of 60 fish samples were investigated for the microplastic presence, abundance, and morphological types within the guts and gills of commercial fish consisting of seven (7) species: Siganus javus (SJ:n=5), Leiognathus splendens (LS: n=8), Leiognathus blochii (LB: n=5), Mugil cephalus (MC: n=19 ), Strongylura leiura (SL: n=10), Stolephorus indicus (SI: n=10), and Caranx heberi (CH: n=3) with different feeding habits and habitats. Samples were collected between July–December 2022. Fish gut content was screened for the presence of MPs using the alkaline digestion and density gradient separation technique (NaCl hypersaline solution) and examined using a stereomicroscope and micro-Fourier transform infrared spectrometer (m-FTIR). Microplastics, ranging from 0.05 to 4.80 mm, were found in the investigated fish species. Remarkably, this study revealed that 51.67% and 32.00 % of the fish samples contained microplastic in their guts and gills respectively. A total number of 67 MP particles (size < 5 mm) were found in the excised fish guts of the seven species. The most common morphology of microplastics discovered in fish guts was fragments, which accounted for 87.5% of all MPs present. The MP content in guts differed between species. Of that Mugil cephalus recorded the greatest amount of MP ingestion, with an average MP count of 2.68±0.23 items per individual in fish gut corresponding to an average abundance of 0.22±0.26 particles/g and 0.84 ±0.46 items per individual in gills corresponding to an average abundance of 0.41±0.68 particles/g. The majority of ingested particles were fragments (40.3%), followed by fibers (34.33%), films (19.40%), microbeads (4.48%), filament (2.29%), and no pellets were observed. In terms of colour, the most abundant were blue (58.20%), followed by green (13.43%), transparent particles (8.96%), yellow (7.46%), red (5.97%), black (2.98%), white, brown, pink (1.49%) were found in low number. The majority of MPs presented were identified by m-FTIR as particles of polypropylene and polyethylene (HDPE), rayon. The results are evident in the growing threat of MPs on biological matrices and ingested MPs in edible fish species present in the Negombo lagoon.
Pervasive Microplastic Ingestion by Commercial Fish Species from a Natural Lagoon Environment
(Water, 2024) Athukorala, A.; Amarathunga, A. A. D.; De Silva, D. S. M.; Bakir, A.; McGoran, A. R.; Sivyer, D. B.; Dias, B. C. G.; Kanishka, W. S.; Reeve, C.
Microplastics have emerged as a significant global environmental concern in the recent decade. The aim of this study was to elucidate microplastic contamination of commercial fish species in a natural lagoon environment. Microplastic contamination was examined in the gastrointestinal tracts and gills of 157 commercial fish from 18 species with varying feeding habits in a vital and sensitive lagoon ecosystem, which connects to the Indian ocean. Microplastics were extracted using digestion, followed by stereomicroscopic inspection using Nile Red stain, and identified via μ-FTIR analysis. Over half of studied fishes ingested microplastics (54.14%). Filaments (50%) and blue items (43%) were the most commonly ingested. Of all the fish species, Eubleekeria splendens had the highest average concentration of microplastics in GIT (1.41 ± 2.52 items/g w.w. tissues), although no statistically significant difference in amount of ingested microplastics (items/g w.w. tissues) was observed among species. The highest concentrations of inhaled microplastics were recorded in Sillago vincenti (1.38 ± 1.30 items/g w.w. tissues). The majority of the extracted microplastics (33%) belonged in the size class 500–1500 μm with rayon, polyethylene terephthalate, and polypropylene as the primary polymers. This study found no correlation between microplastic ingestion and fish species and feeding habits, but a positive correlation with fish size was observed. These findings reveal widespread microplastic contamination in edible fish, posing potential risks to commercially important species due to increasing pollution in lagoon ecosystems.