Mikro-plastikoen iturriak eta egoera orokorra mundu mailako itsaso eta ozeanoetan

Abstract

Until recent years we have been unaware of the presence of microplastics (MPs) in the marine environment. MPs are plastic particles smaller than 5 mm accumulated in seas and shores, due to the dumping of small plastic materials used in certain products, or by the fragmentation of larger plastic objects. The actual extent of their risk is yet unknown and their origin, occurrence and impacts are being investigated. This work has included a number of researches on MPs worldwide, with the aim of presenting a global situation on the topic, emphasizing the limits and knowledge barriers. MPs are found in all marine compartments: on the water surface, in sediments (at the seabed and beaches) and in biota. MPs abundance vary significantly depending on the compartment, the measurement methodology, the geographic area and even on the sampling period. Difficulties are found when comparing researches, as different methodologies are being used. For this reason, there is an urgent need to standardize procedures. Polypropylene, polyethylene and polystyrene are the most common materials in MPs, in agreement with the most commonly used plastic materials in the world. The information on the distribution and impacts of MPs in the oceans is still limited. For this reason, research on the topic must be deepened at different scales (locally, regionally and globally) with the aim to: agree methodologies, set monitoring programmes, assess sources, deepen on the degradation paths of secondary MPs, and analyse the impacts on environmental and human health.