RESUMEN
Microplastics (MPs) are among the most common pollutants in the environment. Because of their small size, availability, and similarity to natural foods, they are commonly ingested by marine organisms. They can cause health problems in living organisms due to their bioaccumulation potential. It is, therefore, unknown whether endocrine-disrupting chemicals (EDCs), in particular estrogens, are capable of adhering to the diverse types of MPs found in water. Two MP polymers (low-density polyethylene (LDPE) and polyethene terephthalate (PET)) that could pose a threat to fish were tested for estrogen adsorption. The adsorption capacity of MP pellets was studied for 30 days in the effluent and influent of a wastewater treatment-plant. A laboratory simulation was conducted to validate the field and laboratory findings. We found that the concentrations of five types of estrogen ((diethylstilbestrol (DES), estrone (E1), 17ß-estradiol (E2), estriol (E3), 17α-ethinyl estradiol (EE2)) were higher in the influent than the effluent streams. LDPE and PET MPs exposed to influent water in the laboratory had higher estrogen levels than wastewater treatment plants (WWTP) pellets. The PET pellets showed the highest adsorption affinity to EE2, while the LDPE pellets showed the highest affinity to E2. As a result, this study provided baseline data to investigate the estrogen adsorption capacity in MPs.
Asunto(s)
Contaminantes Químicos del Agua , Purificación del Agua , Animales , Estrógenos/análisis , Polietileno , Plásticos , Microplásticos , Eliminación de Residuos Líquidos , Contaminantes Químicos del Agua/análisis , Etinilestradiol , Estradiol , Agua , Monitoreo del AmbienteRESUMEN
Microplastics are a group of ubiquitous persistent pollutants that have rapidly attracted much attention from the scientific community as well as the general public due to the growing awareness of the environmental risks they pose. However, due to limitations and variations in sampling, analytical measurement methods, and the different units used for reporting data, reliable comparisons between studies in the Gulf region and internationally are not straightforward. This study proposes standardized protocols for marine sediment, seawater, marine biota and aerosol (1) sampling, (2) sample processing, (3) sample identification and (4) reporting units to be used. An attempt has been made to highlight the limitations of the widely employed strategies for sampling microplastics in seawater, where a large portion of the microplastics is not sampled due to the mesh sizes used. The issues with the processing of biota samples and aerosols are likewise addressed, and recommendations are also made for standardization of units for reporting microplastic quantification. Protocols for collection of bottom sediments and aerosols are also proposed. These are the environmental matrixes for which there are no harmonized protocols in the Gulf region; hence if a standardized approach is adopted, it will enable and improve comparisons between the studies within this region and can be useful for similar studies in other marine areas as well.
Asunto(s)
Plásticos , Contaminantes Químicos del Agua/análisis , Monitoreo del Ambiente , Sedimentos Geológicos , Microplásticos , Océanos y MaresRESUMEN
Microplastic pollution status in Kuwait coastal areas was assessed A total of 44 intertidal locations were sampled for beach sediment. Short trawls (40) were conducted. In addition, 87 fish and mussels gastrointestinal contents were examined. Microplastics were characterized by Raman spectroscopy. Contrary to the expectation very few microplastic particles were found. Only 37 MPs were detected in beach sediments at 15 locations. Seawater trawls indicated that MPs were low in the numbers. MPs were found in just two samples from Kuwait Bay and also in two samples from the southern areas. In biota, only 3 pieces of plastics were recovered from gastrointestinal tracks of hamour fish. The identified MPs were dominantly polypropylene, polyethylene and polystyrene. It appeared that the microplastic levels in sediment, water and biota were much lower compared to published values from adjoining areas, however, were comparable to the absolute numbers of particles from Qatar and Oman.
Asunto(s)
Plásticos , Contaminantes Químicos del Agua/análisis , Animales , Monitoreo del Ambiente , Sedimentos Geológicos , Kuwait , Microplásticos , Omán , Qatar , Encuestas y CuestionariosRESUMEN
The pollution of coastal regions worldwide has been of a great concern due to the presence of endocrine disrupting chemicals (EDCs). These chemicals find their way to the marine environment via the sewage treatment plants (STPs). Hence, this study was designed to investigate the status and sources of EDCs and their effect on fish in Kuwait's coastal areas, from the chemical and biological perspectives. The assessment of three STPs indicated the presence of significant levels of phthalates (19 and 31µg/l), alkylphenols (85 and 159ng/l), and estrogens (30 and 368ng/l) in both inflow and outflow samples. The analysis of samples from field exposure sites revealed significant levels of EDCs in seawater (phthalates: 2.1-4.6µg/l; alkylphenols: 1.2-16.4ng/l; estrogens: 0-36.2ng/l) and sediment (phthalates: 2.1-15.7mg/kg dry wt; alkyphenols: 2.5-15.1µg/kg dry wt.; estrogens: 4.1-214.2µg/kg dry wt.) samples. The biological perspective investigated through the exposure of fish to sewage outlets at five sites. The hepatosomatic index (HSI) revealed a higher level in winter samples 0.48-0.79%) in comparison to summer samples 1-1.5%). Histological observation of hepatic tissue of fish exposed during winter months in all sites, showed much less necrotic changes and hepatic vacuolation in the hepatic tissue of summer exposed fish. Imunnohistochemistry evidences revealed a significant level of positive signals and Vtg localization in the hepatic tissue as the results support the histopathological alterations observed. Results of enzyme-linked immunosorbent assay (ELISA) showed no significant difference between the plasma protein content of winter and summer samples. Overall, the study suggest that there is possible local source or a chronic input of untreated and/or partially treated water due to the significant levels of phthalates, alkyphenols, and estrogens detected in the Kuwait Bay. These levels were enough to initiate alteration in the hepatic tissue of fish exposed to the sewage outlets in Kuwait for two weeks.
Asunto(s)
Disruptores Endocrinos/toxicidad , Hígado/efectos de los fármacos , Dorada/metabolismo , Agua de Mar/química , Aguas del Alcantarillado/química , Contaminantes Químicos del Agua/toxicidad , Animales , Disruptores Endocrinos/análisis , Ensayo de Inmunoadsorción Enzimática , Kuwait , Hígado/metabolismo , Hígado/patología , Vitelogeninas/metabolismo , Contaminantes Químicos del Agua/análisis , Purificación del AguaRESUMEN
The sources and levels of endocrine disrupting compounds in Kuwait's coastal areas were investigated. Phthalates, alkylphenols and estrogens were measured in the inflows and outflows of three sewage treatment plants as well as in the seawater and sediments from the sewage impacted coastal areas. Phthalate levels in the inflow of the treatment plants ranged from 8.9 to 78.3µg/l; alkylphenols from 0.7 to 279ng/l and estrogens from 30 to 368ng/l. On average, the treatment plants removed about 80% of these compounds. The outflows, however, contained significant levels of all three classes of compounds. The seawater from the sewage impacted area also contained detectable levels of these compounds. Sediment samples from these locations contained elevated levels of phthalates (ranging from 2145 to 15,722µg/kg) and lower levels of alkylphenols (ranging from 2.49 to 15.14µg/kg) and estrogens (ranging from 4.1 to 214µg/kg, dry wt.).
Asunto(s)
Disruptores Endocrinos/análisis , Sedimentos Geológicos/química , Agua de Mar/química , Contaminantes Químicos del Agua/análisis , Estrógenos/análisis , Kuwait , Fenoles/análisis , Ácidos Ftálicos/análisis , Aguas del AlcantarilladoRESUMEN
The intestine of marine teleosts produces carbonate precipitates from ingested calcium as part of their osmoregulatory strategy in seawater. The potential for estrogens to control the production of intestinal calcium carbonate and so influence osmoregulation was investigated in seawater-acclimated rainbow trout following intraperitoneal implantation of 17ß-estradiol (E2) at two doses (0.1 and 10 µg E2 g(-1)). Levels of plasma vitellogenin provided an indicator of estrogenic effect, increasing significantly by three and four orders of magnitude at the low and high doses, respectively. Plasma osmolality and muscle water content were unaffected, whereas E2-treated fish maintained lower plasma [Na(+)] and [Cl(-)]. Plasma [Ca(2+)] and [Mg(2+)] and muscle [Ca(2+)] increased with vitellogenin induction, whereas the intestinal excretion of calcium carbonate was reduced. This suggests that elevated levels of circulating E2 may enhance Ca(2+) uptake via the gut and simultaneously reduce CaCO(3) formation, which normally limits intestinal availability of Ca(2+). Increasing E2 caused an elevation of [Na(+)] and [Cl(-)] and a reduction of [HCO(3(-))] in intestinal fluid. We speculate that E2 may influence a number of intestinal ion transport processes that ultimately may influence water absorption: (1) reduced NaCl cotransport, (2) reduced Cl(-) uptake via Cl(-)/HCO(3(-)) exchange and (3) reduced precipitation of Ca(2+) and Mg(2+) carbonates. Despite these effects on intestinal ion and water transport, overall osmoregulatory status was not compromised in E2-treated fish, suggesting the possibility of compensation by other organs.
Asunto(s)
Aclimatación/efectos de los fármacos , Carbonato de Calcio/metabolismo , Estradiol/farmacología , Mucosa Intestinal/metabolismo , Oncorhynchus mykiss/fisiología , Agua de Mar , Equilibrio Hidroelectrolítico/efectos de los fármacos , Absorción/efectos de los fármacos , Animales , Líquidos Corporales/efectos de los fármacos , Líquidos Corporales/metabolismo , Calcio/sangre , Precipitación Química/efectos de los fármacos , Femenino , Intestinos/efectos de los fármacos , Magnesio/sangre , Músculos/efectos de los fármacos , Músculos/metabolismo , Oncorhynchus mykiss/sangre , Vitelogeninas/sangre , Equilibrio Hidroelectrolítico/fisiologíaRESUMEN
Euryhaline teleosts regulate their internal osmotic and ionic status across a wide range of external salinities. Studies often rely on measurements on plasma when osmoregulatory status is perturbed, whereas tissue measurements are used for small fish with limited blood volume. However, a direct comparison is lacking for plasma and various tissues. In the present study the relationships between plasma, white muscle and carcass were examined for a range of osmoregulatory variables in rainbow trout (Oncorhynchus mykiss) following challenge with an acute (24 h) transfer from freshwater to a hyper-osmotic salinity of either 25 or 35. Significant increases in plasma osmolality, [Na+], [Clâ»], [Ca²+], and [Mg²+] were observed when salinity was increased, but plasma [K+] was unaffected. The water content of both tissues showed reciprocal changes to plasma osmolality. The carcass content of all ions measured showed a significant increase at the highest ambient salinity. In white muscle, Na+, K+ and Mg²+ showed significant increases with external salinity, but Clâ» and Ca²+ were unaffected. Measurements from both tissues can provide reliable surrogates for most of the plasma osmoregulatory variables except Clâ» and Ca²+ when using white muscle tissue. In the case of internal regulation of K+ both tissues provide sensitive and quantitatively similar indicators of environmental salinity disturbance, whereas plasma does not.