In recent years there has been a sharp increase in the concentration of microplastics in aquatic environments, so much so that it has become a global problem, studied by many researchers. In the present study the transfer of these small particles to medaka (Oryzias melastigma) and zebrafish (Danio rerio) larvae through a diet based on Paramecium and Artemia previously exposed to the microparticles is evaluated. The larvae, of different ages, are fed for different periods of time with Paramecium or Artemia nauplii previously exposed to fluorescent MPs of different sizes (MP5: 1-5 µm, MP20 : 10-20 µm). In general, in both species, MP5 particles were absorbed more efficiently than MP20s. Furthermore, MPs can adsorb organic substances that transfer and accumulate in organisms, as in the case of BaP, which adsorbed to MPs, has been measured in organisms by microscopic observation of its specific fluorescence. Furthermore, induction of the cyp1a gene was also measured to determine the bioavailability of BaP in addition to microscopic investigations. In conclusion, the MPs are effectively transferred from the prey to the juveniles of medaka and zebrafish which can manifest in addition to their accumulation also alterations of the reproductive system and of the growth, if subjected to chronic exposure. Finally, this study underlines the importance of studying the presence and effects of MPs in organisms, since, through trophic transfer they can reach humans.
Negli ultimi anni c'è stato un forte incremento della concentrazione di microplastiche negli ambienti acquatici, tanto da diventare un problema a livello globale, studiato da molti ricercatori. Nel presente studio viene valutato il trasferimento di queste piccole particelle a larve di medaka (Oryzias melastigma) e di zebrafish (Danio rerio) attraverso una dieta a base di Paramecium e Artemia precedentemente esposte alle microparticelle. Le larve, di diverse età, vengono alimentate per diversi periodi di tempo con Paramecium o naupli di Artemia precedentemente esposti a MP fluorescenti di diverse dimensioni (MP5 : 1-5 µm, MP20 : 10-20 µm). In generale in entrambe le specie, le particelle MP5 sono state assorbite in modo più efficiente rispetto alle MP20. Inoltre le MPs possono adsorbire sostanze organiche che si trasferiscono e accumulano negli organismi, come nel caso del BaP, che adsorbito alle MPs, è stato misurato negli organismi tramite osservazione al microscopio della sua specifica fluorescenza. Inoltre, per determinare la biodisponibilità del BaP oltre alle indagini microscopiche è stata anche misurata l'induzione del gene cyp1a. In conclusione, le MPs vengono trasferite efficacemente dalle prede ai giovanili di medaka e di zebrafish che possono manifestare oltre al loro accumulo anche alterazioni del sistema riproduttivo e della crescita, se sottoposti ad un'esposizione cronica. Infine questo studio sottolinea l’importanza di studiare la presenza e gli effetti delle MPs negli organismi, poiché, attraverso il trasferimento trofico possono arrivare fino all’uomo.
MICROPLASTICHE E CONTAMINANTI ASSORBITI – ESPOSIZIONE TROFICA IN LARVE DI DANIO RERIO E ORYZIAS MELASTIGMA
NOVELLI, LAETITIA
2020/2021
Abstract
In recent years there has been a sharp increase in the concentration of microplastics in aquatic environments, so much so that it has become a global problem, studied by many researchers. In the present study the transfer of these small particles to medaka (Oryzias melastigma) and zebrafish (Danio rerio) larvae through a diet based on Paramecium and Artemia previously exposed to the microparticles is evaluated. The larvae, of different ages, are fed for different periods of time with Paramecium or Artemia nauplii previously exposed to fluorescent MPs of different sizes (MP5: 1-5 µm, MP20 : 10-20 µm). In general, in both species, MP5 particles were absorbed more efficiently than MP20s. Furthermore, MPs can adsorb organic substances that transfer and accumulate in organisms, as in the case of BaP, which adsorbed to MPs, has been measured in organisms by microscopic observation of its specific fluorescence. Furthermore, induction of the cyp1a gene was also measured to determine the bioavailability of BaP in addition to microscopic investigations. In conclusion, the MPs are effectively transferred from the prey to the juveniles of medaka and zebrafish which can manifest in addition to their accumulation also alterations of the reproductive system and of the growth, if subjected to chronic exposure. Finally, this study underlines the importance of studying the presence and effects of MPs in organisms, since, through trophic transfer they can reach humans.| File | Dimensione | Formato | |
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Descrizione: studio sulle microplastiche e contaminanti assorbiti
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https://hdl.handle.net/20.500.12075/8302