Prevention and control strategies for non-regulated industrial microplastic spills

Microplastics caused by industrial activity are still at an early stage of research and, in general, there is a significant lack of knowledge about the specific industries that contribute to microplastic pollution. In fact, studies on marine plastics and microplastics do not usually report their potential industrial origin, due to the difficulty of distinguishing them. However, in some cases it is possible to distinguish the industrial origin of primary microplastics, such as pellets used by the plastic industry. Pellets constitute a major category of microplastics detected along marine coastlines, primarily resulting from losses during handling and transportation. Although the European Commission recently agreed a regulation on unintentional pellet leakage, current industrial discharge regulations do not include specific controls for microplastics, since in addition, there are still no standardised procedures for the analytical determination of microplastics in wastewater samples. This study aims to identify standard parameters currently included in industrial discharge regulations that could serve as indicators of pellet-type microplastic spills from the plastics industry under hypothetical stormwater discharge monitoring. The suitability of total suspended solids and volatile suspended solids parameters is evaluated and verified. Thus, monitoring these parameters at discharge control points within stormwater networks of the plastics industry represents a technically, economically, and environmentally advantageous strategy for preventing pellet discharges. Finally, additional measures for the control and containment of microplastic spills from industry are also proposed.