RESUMO
This study established a unique approach to assess fecal contamination by measuring fecal sterols, especially coprostanol (5ß-cholestanol-3ß-ol, 5ß) and cholestanol (5α-cholestan-3ß-ol, 5α) and their ratio 5ß/(5ß + 5α) alongside triclosan (TCS) and methyl-triclosan (MTC) in beached plastic pellets across 40 countries. Coprostanol concentrations ranged from 3.6 to 8190 ng/g pellet with extremely high levels in densely populated areas in African countries. The 5ß/(5ß + 5α) ratio was not affected by the difference in residence time of pellets in aquatic environments, and their spatial pattern showed a positive correlation with that of sedimentary sterols, demonstrating its reliability as an indicator of fecal contamination. Pellets from populated areas of economically developing countries, i.e., Africa and Asia, with lower coverage of wastewater treatment exhibited higher 5ß/(5ß + 5α) ratios (â¼0.7) corresponding to â¼1% sewage in seawater, while pellets from developed countries, i.e., the USA, Canada, Japan, and Europe, with higher coverage of modern wastewater treatment displayed lower ratios (â¼0.5), corresponding to the first contact limit. Triclosan levels were higher in developing countries (0.4-1298 ng/g pellet), whereas developed countries showed higher methyl-triclosan levels (0.5-70 ng/g pellet) due to TCS conversion during secondary treatment. However, some samples from Japan and Europe displayed higher TCS levels, suggesting contributions from combined sewage overflow (CSO). Combination of 5ß/(5ß + 5α) and MTC/TCS ratios revealed extreme fecal contamination from direct input of raw sewage due to inadequate treatment facilities in some African and South and Southeast Asian countries.
Assuntos
Triclosan/análogos & derivados , Poluentes Químicos da Água , Colestanol/análise , Esgotos/análise , Reprodutibilidade dos Testes , Esteróis/análise , Monitoramento Ambiental/métodos , Poluentes Químicos da Água/análiseRESUMO
To select urban greening tree species suitable for the purification of the atmosphere polluted by black carbon (BC) particles, it is necessary to clarify the determinants of the amount of BC particles deposited on the tree leaves. In the present study, we investigated the relationship between the amount of BC particles that were deposited from the atmosphere and firmly adhered to the leaf epicuticular wax, and leaf surface traits in seedlings of nine tree species grown for two years under natural conditions (Fuchu, Tokyo, Japan). There was a significant interspecific difference in the maximum amount of BC particles deposited on the leaf surface, and the order was as follows: Ilex rotunda > Cornus florida > Osmanthus fragrans > Cornus kousa > Quercus glauca â Quercus myrsinifolia > Magnolia kobus â Zelkova serrata â Styrax japonicus. In the nine tree species, significant highly positive correlations were observed between the amount of BC particles deposited on the leaf surface, and the hydrophobicity of leaf epicuticular wax determined by its chemical composition. Therefore, we concluded that the hydrophobicity of leaf epicuticular wax is an important determinant of the amount of BC particles deposited on the leaf surface of urban greening tree species.
This is the first paper that shows that the hydrophobicity of leaf epicuticular wax is an important determinant of the amount of BC particles deposited on the leaf surface of urban greening tree species. This study will provide the basic and novel information for the selection of urban greening tree species suitable for the purification of the air polluted by BC particles.
Assuntos
Poluentes Atmosféricos , Árvores , Biodegradação Ambiental , Folhas de Planta/química , Plântula/química , Carbono/análise , Poluentes Atmosféricos/análise , Monitoramento Ambiental , Material Particulado/análiseRESUMO
The tsunami caused by the Great East Japan Earthquake on March 11, 2011 disturbed coastal environments in the eastern Tohoku region in Japan. Numerous terrestrial materials, including anthropogenic organic compounds, were deposited in the coastal zone. To evaluate the impacts of the disaster, we analyzed PCBs, LABs, PAHs, and hopanes in mussels collected from 12 locations in the east of Tohoku during 2011-2015 (series A) by GC-ECD or GC-MS and compared them with results from mussels collected from 22 locations around Japan during 2001-2004 (series B). Early LAB concentrations in series A at some locations were higher than the maximum concentrations in series B but decreased during the 5 years. Because LABs are molecular markers for sewage, these decreases are consistent with the recovery of sewage treatment plants in these areas. Early PAH concentrations at several locations were higher than the maximum concentrations in series B but also decreased. These high concentrations would have been derived from oil spills. The decreases of both LABs and PAHs indicate that these locations were affected by the tsunami but recovered. In contrast, later high concentrations of target compounds were detected sporadically at several locations. This pattern suggests that environmental pollution was caused by human activities, such as reconstruction. To understand the long-term trend of environmental pollution induced by the disaster, continuous monitoring along the Tohoku coast is required.
Assuntos
Terremotos , Monitoramento Ambiental , Poluentes Ambientais/análise , Japão , Bifenilos Policlorados/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Análise Espaço-Temporal , TsunamisRESUMO
Our previous study suggested the transfer of polybrominated diphenyl ether (PBDE) flame retardants from ingested plastics to seabirds' tissues. To understand how the PBDEs are transferred, we studied leaching from plastics into digestive fluids. We hypothesized that stomach oil, which is present in the digestive tract of birds in the order Procellariiformes, acts as an organic solvent, facilitating the leaching of hydrophobic chemicals. Pieces of plastic compounded with deca-BDE were soaked in several leaching solutions. Trace amounts were leached into distilled water, seawater, and acidic pepsin solution. In contrast, over 20 times as much material was leached into stomach oil, and over 50 times as much into fish oil (a major component of stomach oil). Analysis of abdominal adipose, liver tissue, and ingested plastics from 18 wild seabirds collected from the North Pacific Ocean showed the occurrence of deca-BDE or hexa-BDEs in both the tissues and the ingested plastics in three of the birds, suggesting transfer from the plastic to the tissues. In birds with BDE209 in their tissues, the dominance of BDE207 over other nona-BDE isomers suggested biological debromination at the meta position. Model calculation of PBDE exposure to birds based on the results of the leaching experiments combined with field observations suggested the dominance of plastic-mediated internal exposure to BDE209 over exposure via prey.
Assuntos
Aves/fisiologia , Retardadores de Chama/farmacocinética , Éteres Difenil Halogenados/farmacocinética , Plásticos/análise , Tecido Adiposo/metabolismo , Animais , Monitoramento Ambiental/métodos , Feminino , Retardadores de Chama/análise , Mucosa Gástrica/metabolismo , Éteres Difenil Halogenados/análise , Fígado/metabolismo , Oceano Pacífico , Plásticos/química , Plásticos/farmacocinética , Água do Mar/química , Estômago/química , Distribuição TecidualRESUMO
Plastics can contain two types of organic contaminants; absorbed from ambient water, and already contained as additives. To investigate the bioaccumulation of these substances, we conducted two types of exposure experiments using mussels and polyethylene microplastics with absorbed PCBs and containing four types of additives (BDE209, DBDPE, UV327 and UV234). After dietary exposure for 15 days, significantly higher concentrations of total PCBs, UV327 and UV234 were detected in the gonad of exposed groups than in the control groups, respectively. However, no significant differences in BDE209 or DBDPE levels were observed between the control and exposure groups. Although a higher transfer ratio was shown for PCB congeners with octanol-water partition coefficients (logKow) below 7, the ratio was lower for higher-hydrophobic PCBs with logKow above 7. This suggests that higher hydrophobic compounds (not only highly chlorinated PCBs, but also BDE209 and DBDPE) tend not to desorb or leach from plastics.
Assuntos
Bivalves , Exposição Dietética , Microplásticos , Bifenilos Policlorados , Poluentes Químicos da Água , Animais , Poluentes Químicos da Água/análise , Microplásticos/análise , Exposição Dietética/análise , Bifenilos Policlorados/análise , Éteres Difenil Halogenados/análise , Monitoramento AmbientalRESUMO
Benzotriazole-type ultraviolet stabilizers (BUVSs) are emerging contaminants whose exposure to wildlife is of concern. In this study, we investigated the contamination status of BUVSs in green turtles (Chelonia mydas) breeding at Ogasawara Islands, Japan, through chemical analysis of 10 BUVSs and 26 congeners of polychlorinated biphenyls (PCBs) in adipose tissue (n = 21) and blood plasma (n = 9). BUVSs were detected significant levels in adipose tissue (19 of 21 turtles), and UV-327 (not detected - 14.8 ng/g-lipid, detection frequency: 76 %), UV-326 (not detected - 24.1 ng/g-lipid, 29 %), and UV-328 (not detected - 5.8 ng/g-lipid, 24 %) were frequently detected. Turtles exhibiting sporadically high concentrations of BUVSs (>10 ng/g-lipid) did not necessarily correspond to individuals with high total PCB concentrations (1.03-70.2 ng/g-lipid). The sporadic occurrence pattern of BUVSs suggested that these contaminants in sea turtles cannot be explained solely by diet but are likely derived from plastic debris.
Assuntos
Monitoramento Ambiental , Bifenilos Policlorados , Triazóis , Tartarugas , Poluentes Químicos da Água , Animais , Oceano Pacífico , Poluentes Químicos da Água/análise , Triazóis/análise , Bifenilos Policlorados/análise , Japão , Cruzamento , Protetores Solares , Tecido AdiposoRESUMO
Plastic litter containing additives is potentially a major source of chemical contamination in remote areas. We investigated polybrominated diphenyl ethers (PBDEs) and microplastics in crustaceans and sand from beaches with high and low litter volumes on remote islands that were relatively free of other anthropogenic contaminants. Significant numbers of microplastics in the digestive tracts, and sporadically higher concentrations of rare congeners of PBDEs in the hepatopancreases were observed in coenobitid hermit crabs from the polluted beaches than in those from the control beaches. PBDEs and microplastics were detected in high amounts in one contaminated beach sand sample, but not in other beaches. Using BDE209 exposure experiments, similar debrominated products of BDE209 in field samples were detected in the hermit crabs. The results showed that when hermit crabs ingest microplastics containing BDE209, BDE209 leaches out and migrates to other tissues where it is metabolized.
Assuntos
Anomuros , Poluentes Químicos da Água , Animais , Éteres Difenil Halogenados/análise , Anomuros/metabolismo , Bioacumulação , Areia , Microplásticos , Plásticos/metabolismo , Poluentes Químicos da Água/análiseRESUMO
Polybrominated diphenyl ethers (PBDEs) are known to be broken down by debromination reactions in the natural environment, such as by photolysis, microbial and metabolic processes. Although species-specific debromination of PBDEs by fish has also been reported, it has only rarely been studied from the phylogenetic perspective. The objective of this study is to reveal the factors affecting species-specific debromination through validation between the bioaccumulation of PBDEs in muscle tissue and the ability to debrominate BDE99. As environmental observations, PBDE concentrations in muscle tissues were analyzed in 25 wild fish (Cyprinidae, Gobiidae and others). As in vitro experiments, debromination experiments were conducted using the hepatic microsomes of 21 fish species. Significant amounts of BDE99 were detected in almost none of the Cyprinidae. A relatively higher debromination ability was confirmed in the Cyprinidae in in vitro experiments. The Cyprinidae thus appears to be a family with high debromination ability. BDE99 has been detected in some goby species but not others. This pattern was also seen in in vitro experiments, suggesting that debromination ability is not consistent within the Gobiidae. In further quantitative comparisons, kinetic parameters such as Km and vmax were determined for selected fish species. The common carp (Cyprinus carpio) and the Japanese crucian carp (Carassius cuvieri), both Cyprinidae, showed higher vmax values, whereas vmax values among three Gobiidae diverged widely. A comparison of field observations and in vitro experiments, revealed the bioaccumulation ratio of BDE99 to be affected by the BDE99 debromination ability of each fish species. This is the first report on classification of BDE99 accumulation ratio by debromination ability and a phylogenetic species comparison based on kinetic parameters for debromination reactions of PBDEs by fish.
Assuntos
Carpas , Poluentes Químicos da Água , Animais , Bioacumulação , Éteres Difenil Halogenados/análise , Microssomos Hepáticos/metabolismo , Filogenia , Poluentes Químicos da Água/análiseRESUMO
Marine organisms ingest microplastics directly from water and indirectly from food sources. Ingesting microplastics can lead to the accumulation of plastic-derived chemicals. However, the relative contributions of the two exposure routes to the accumulation of plastic-derived chemicals in organisms are unknown. Using microplastics containing two brominated flame retardants (BFRs; BDE209 and DBDPE) and three UV stabilizers (UVSs; UV-234, UV-327, and BP-12), we performed exposure experiments to compare chemical accumulation patterns in fish (Myoxocephalus brandti) between exposure from water and prey (Neomysis spp.). We found significantly higher concentrations of BFRs in fish fed microplastic-contaminated prey than fish exposed to microplastics in the water. However, we observed similar concentrations of UVSs in fish exposed to both sources. As BFRs are more hydrophobic than UVSs, the differences may reflect the hydrophobic nature of the additives. Our findings indicate that both exposure routes are crucial to understanding the accumulation of plastic additives in fish.
Assuntos
Retardadores de Chama , Microplásticos , Animais , Plásticos , Peixes , ÁguaRESUMO
On 10 August 2021, a face mask (14 cm × 9 cm) was found in the feces of a juvenile green turtle, by-caught alive in a set net off the northeast coast of Japan. Although sea turtles have been monitored in this region over the last 15 years (n = 76), face masks had never been found before the Covid-19 pandemic and this is the first detection. Fourier-transform infrared spectroscopy identified the mask as polypropylene. Estrogenic active benzotriazole-type UV stabilizers such as UV329 were detected in commercially available polypropylene face masks. Exposure of marine organisms ingesting plastics to endocrine-disrupting chemicals and physical injury are of concern. This study indicates that changes in human life in the pandemic are beginning to affect marine life. Precautionary actions including establishment of appropriate waste management of personal protective equipment and use of safe additives are urgently needed.
Assuntos
COVID-19 , Tartarugas , Animais , Ecossistema , Humanos , Pandemias , Plásticos , SARS-CoV-2RESUMO
Persistent organic chemicals are non-biodegradable in nature and have a tendency to bioaccumulate in the top organisms of the food chain. We measured persistent organic chemicals, including polychlorinated biphenyls (PCBs), dichlorodiphenyldichloroethylene (DDE), and benzotriazole-based ultraviolet stabilizers (UV-BTs), in the serum of captive king penguins (Aptenodytes patagonicus) using gas chromatography with an electron capture detector and mass spectrometry to examine their age-related accumulation. PCBs, DDE, UV-PS, and UV-9 were detected in the blood of captive king penguins, and the concentrations of total PCBs, DDE, and UV-9 were positively correlated with age. These results suggest that there is a similar age-related accumulation of persistent organic chemicals in marine birds in the wild, and that older individuals are at a higher risk of contamination.
Assuntos
Bifenilos Policlorados , Spheniscidae , Animais , Bifenilos Policlorados/análise , Diclorodifenil Dicloroetileno , Compostos OrgânicosRESUMO
OBJECTIVES: Macrolides have a long history of use in animals and humans. Dynamics of macrolide-antibiotic resistance genes (ARGs) in waterways from the origin to the sea has not been reported. METHODS: Resistant bacterial rate was measured by culture method, and copy numbers of macrolide-ARGs, mef(A), erm(B), mph(B), mef(C)-mph(G), and mobile genetic elements (MGEs) traI and IntI1 were quantitated in environmental DNA. Community composition in each site was investigated by 16S rRNA gene metagenomic sequencing. In Yilan area, antibiotics were quantitated. RESULTS: Surface water samples from pig farms to the sea in southern and northern areas in Taiwan were monitored. Macrolide-resistant bacteria accounted for 3%-28% of total colony-forming bacteria in aquaculture ponds and rivers, whereas in pig farm wastewater it was 26%-100%. Three common macrolide-ARGs mef(A), erm(B), and mph(B) and the relatively new mef(C)-mph(G) were frequently detected in pig farms, but not in aquaculture ponds and the sea. Rivers receiving pig wastewater showed ARG contamination similar to the pig farms. Among the MGEs, IntI1 was frequently distributed in all sites and was positively related to mef(A), erm(B), and mph(B) but not to mef(C)-mph(G). CONCLUSION: Pig farms are the origin of macrolide-ARGs, although macrolide contamination is low. Since lincomycin was detected in pig farms in the northern area, the increase of macrolide-ARGs is a future concern due to cross-resistance to lincomycin. ARGs abundance in aquaculture ponds was low, though MGEs were detected. Relation of IntI1 to ARG suggests convergence of ARGs to specific MGEs might be time/history dependent.
Assuntos
Antibacterianos , Macrolídeos , Animais , Antibacterianos/farmacologia , Bactérias , Farmacorresistência Bacteriana/genética , Genes Bacterianos , Sequências Repetitivas Dispersas , Lincomicina , Macrolídeos/farmacologia , RNA Ribossômico 16S/genética , Suínos , Taiwan , Águas Residuárias/microbiologiaRESUMO
Although the debromination of polybrominated diphenyl ethers (PBDEs) in fish species has been studied, environmental factors, such as chemical contamination and habitat temperature, have not been well understood. This study compared debromination of BDE209 by hepatic microsomes of wild and cultured fish. PBDE concentrations in muscle tissue were lower in cultured fish than in wild fish. Debromination activity was high in wild common carp, followed by cultured common carp, moderate in cultured ayu sweetfish, and low in two cultured fish (rainbow trout and cherry salmon) and wild Japanese sea bass. Although common carps have been known as the species which have higher debromination ability, there were differences between wild and cultured common carps. First, wild common carp debrominated much more BDE209 than cultured common carp. Second was debromination of BDE209 lasted 96 h in wild carp but only 24 h in cultured carp. Wild carp were collected from warm wastewater effluent with consistently high concentrations of micropollutants. Cultured carp were collected from colder clean waters. Therefore, environmental factors in debromination include contamination or ambient temperature. To investigate the effects of habitat environment on debromination of PBDEs, we collected wild carp in summer and winter at two different locations with similar PBDE contamination levels. Carp collected from the natural river in winter had the highest BDE99 debromination activity. Although the results indicated seasonal difference of debromination of BDE209, we could not confirm whether habitat temperature or physiological cycle of carp affected to debromination ability. Thus, further investigation such as in vivo experiment is required.
Assuntos
Carpas , Poluentes Químicos da Água , Animais , Água Doce , Éteres Difenil Halogenados/análise , Microssomos Hepáticos/química , Poluentes Químicos da Água/análiseRESUMO
Polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and hopanes were analyzed in plastic resin pellets collected from 19 locations along the Persian Gulf coastline. PCBs were high at locations near industrial areas, where their concentrations (sum of 13 congeners, 54-624 ng/g-pellet) were higher than those in rural coastal towns, which were close to global background levels (<10 ng/g-pellet). PAH concentrations (sum of 27 PAH species) varied from 273 to 15,786 ng/g-pellet and were highest in industrial cities (Bushehr and Bandar Abbas), with a petrogenic signature at most locations, possibly due to the petroleum-based industries, refineries, and tankers. These levels were placed in the extremely polluted category on a global basis. The distribution of hopanes was relatively homogeneous, and their range of concentrations was 8048-59,778 ng/g-pellet. This range had a positive correlation with PAH concentrations. The PAH and hopane results emphasize the ubiquity of petroleum pollution in the Persian Gulf.
Assuntos
Bifenilos Policlorados , Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , Cidades , Monitoramento Ambiental , Oceano Índico , Triterpenos Pentacíclicos , Plásticos , Bifenilos Policlorados/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes Químicos da Água/análiseRESUMO
We measured radiocesium in mussel tissue collected from the Pacific coast of Tohoku from 2011 to 2015 to investigate the temporal and spatial dynamics of radiocesium in the coastal area. Radioactive 137Cs was detected in all the samples collected in 2011, but it was not found in samples from localities north of Sendai after 2012. In contrast, 137Cs was detected in many sites in the Fukushima area even from 2012 to 2015. The fluctuation of 137Cs concentration in mussel tissue seems to reflect the 137Cs concentration in suspended particles in the seawater, suggesting that there was an influx of soil deposition and resuspension of seabed sediment. These results suggest that the 137Cs concentration in mussel tissue sensitively indicates the 137Cs concentration in the environment, and that the "mussel watch" approach is an effective way to understand the dynamics of radiocesium concentrations in coastal areas.
Assuntos
Bivalves , Acidente Nuclear de Fukushima , Monitoramento de Radiação , Poluentes Radioativos da Água , Animais , Césio , Radioisótopos de Césio/análise , Japão , Poluentes Radioativos da Água/análiseRESUMO
Water systems in Southeast Asia accumulate antibiotics and antibiotic resistance genes (ARGs) from multiple origins, notably including human clinics and animal farms. To ascertain the fate of antibiotics and ARGs in natural water environments, we monitored the concentrations of these items in Thailand. Here, we show high concentrations of tetracyclines (72,156.9 ng/L) and lincomycin (23,968.0 ng/L) in pig farms, followed by nalidixic acid in city canals. The city canals and rivers contained diverse distributions of antibiotics and ARGs. Assessments of targeted ARGs, including sul1, sul2, sul3, and tet(M), showed that freshwater (pig farm wastewater, rivers, and canals) consistently contained these ARGs, but these genes were less abundant in seawater. Although sulfonamides were low concentrations (<170 ng/mL), sul1 and sul2 genes were abundant in freshwater (minimum 4.4 × 10-3-maximum 1.0 × 100 copies/16S), suggesting that sul genes have disseminated over a long period, despite cessation of use of this class of antibiotics. Ubiquitous distribution of sul genes in freshwater appeared to be independent of selection pressure. In contrast, water of the coastal sea in the monitored area was not contaminated by these antibiotics or ARGs. The density of Enterobacteriales was lower in seawater than in freshwater, suggesting that the number of ARG-possessing Enterobacteriales falls after entering seawater. From the pig farms, through rivers/canals, to the coastal sea, the occurrence of tetracyclines and tet(M) exhibited some correlation, although not a strong one. However, no correlations were found between concentrations of total antibiotics and ARGs, nor between sulfonamides and sul genes. This is the first comprehensive study showing Thai features of antibiotics and ARGs contaminations. The pig farm is hot spot of antibiotics and ARGs, and sul genes ubiquitously distribute in freshwater environments, which become less abundant in seawater.
Assuntos
Rios , Águas Residuárias , Animais , Antibacterianos/farmacologia , Resistência Microbiana a Medicamentos , Suínos , TailândiaRESUMO
Plastic debris is ubiquitous and increasing in the marine environment [1]. A wide range of marine organisms ingest plastic, and its impacts are of growing concern [2]. Seabirds are particularly susceptible to plastic pollution because of high rates of ingestion [3]. Because marine plastics contain an array of hazardous compounds, the chemical impacts of ingestion are concerning. Several studies on wild seabirds suggested accumulation of plastic-derived chemicals in seabird tissues [4-7]. However, to date, the evidence has all been indirect [4-7], and it is unclear whether plastic debris is the source of these pollutants. To obtain direct evidence for the transfer and accumulation of plastic additives in the tissues of seabirds, we conducted an in vivo plastic feeding experiment. Environmentally relevant exposure of plastics compounded with one flame retardant and four ultraviolet stabilizers to streaked shearwater (Calonectris leucomelas) chicks in semi-field conditions resulted in the accumulation of the additives in liver and adipose fat of 91 to 120,000 times the rate from the natural diet. Additional monitoring of six seabird species detected these chemical additives only in those species with high plastic ingestion rates, suggesting that plastic debris can be a major pathway of chemical pollutants into seabirds. These findings provide direct evidence of seabird exposure to plastic additives and emphasize the role of marine debris ingestion as a source of chemical pollution in marine organisms.
Assuntos
Aves/metabolismo , Plásticos/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Organismos Aquáticos/metabolismo , Exposição Ambiental , Monitoramento AmbientalRESUMO
We collected surface sediment samples from 174 locations in India, Indonesia, Malaysia, Thailand, Vietnam, Cambodia, Laos, and the Philippines and analyzed them for polycyclic aromatic hydrocarbons (PAHs) and hopanes. PAHs were widely distributed in the sediments, with comparatively higher concentrations in urban areas (Sigma PAHs: approximately 1000 to approximately 100,000 ng/g-dry) than in rural areas ( approximately 10 to approximately 100g-dry), indicating large sources of PAHs in urban areas. To distinguish petrogenic and pyrogenic sources of PAHs, we calculated the ratios of alkyl PAHs to parent PAHs: methylphenanthrenes to phenanthrene (MP/P), methylpyrenes+methylfluoranthenes to pyrene+fluoranthene (MPy/Py), and methylchrysenes+methylbenz[a]anthracenes to chrysene+benz[a]anthracene (MC/C). Analysis of source materials (crude oil, automobile exhaust, and coal and wood combustion products) gave thresholds of MP/P=0.4, MPy/Py=0.5, and MC/C=1.0 for exclusive combustion origin. All the combustion product samples had the ratios of alkyl PAHs to parent PAHs below these threshold values. Contributions of petrogenic and pyrogenic sources to the sedimentary PAHs were uneven among the homologs: the phenanthrene series had a greater petrogenic contribution, whereas the chrysene series had a greater pyrogenic contribution. All the Indian sediments showed a strong pyrogenic signature with MP/P approximately 0.5, MPy/Py approximately 0.1, and MC/C approximately 0.2, together with depletion of hopanes indicating intensive inputs of combustion products of coal and/or wood, probably due to the heavy dependence on these fuels as sources of energy. In contrast, sedimentary PAHs from all other tropical Asian cities were abundant in alkylated PAHs with MP/P approximately 1-4, MPy/Py approximately 0.3-1, and MC/C approximately 0.2-1.0, suggesting a ubiquitous input of petrogenic PAHs. Petrogenic contributions to PAH homologs varied among the countries: largest in Malaysia whereas inferior in Laos. The higher abundance of alkylated PAHs together with constant hopane profiles suggests widespread inputs of automobile-derived petrogenic PAHs to Asian waters.
Assuntos
Sedimentos Geológicos/química , Hidrocarbonetos Policíclicos Aromáticos/análise , Hidrocarbonetos Policíclicos Aromáticos/química , Clima Tropical , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/química , Ásia , Monitoramento Ambiental , Oceanos e Mares , Padrões de ReferênciaRESUMO
Filter feeding organisms have been reported to ingest microplastics (MP) in marine environments. However, information regarding how long the ingested MPs are retained in their digestive tracts remains limited. Here, we report the gut retention time (GRT90) and the long-term egestion time of three different sized polystyrene microspheres (1, 10, and 90⯵m) in the Mediterranean mussel Mytilus galloprovincialis. We found significant differences in GRT90 with respect to MP size. With respect to the long-term egestion of MPs, most of the smaller MPs were excreted immediately, although some were detected intermittently until day 40. In comparison, larger MPs were slowly excreted in bulk, after which they were not detected. The results indicate that different sized MPs are retained differently in the digestive tract of mussels. The size-dependent effects of MPs should thus be considered when evaluating the effects of MPs in mussels.