Abstract Plastics are widely used in the construction and building industry, accounting for 23.5% of European plastic consumption. They can replace traditional materials in various applications, including building insulation, piping, paints, adhesives, sealants, roofing, flooring, etc., serve as key components in various composites, and are indispensable for packaging materials and elements that facilitate the construction process itself. Despite their long lifespan, building materials inevitably degrade over time, releasing microplastics (MPs) that contribute to environmental pollution. According to some estimates, annual emissions of MPs in the European Union range from 0.7 to 1.8 Mt, with building paints identified as a dominant source, contributing between 231,000 and 863,000 tons per year. However, reported numbers vary significantly across studies, reflecting the substantial uncertainties still present in quantifying MPs. Now ubiquitous across ecosystems worldwide, MPs have become one of the most pressing concerns of the scientific community, leading to a rapid expansion of research in recent years. Yet less than 0.6% of studies focus on their presence in the construction and building sector, leaving this major industry largely overlooked. This review consolidates scattered knowledge by examining the applications of plastics in the construction and built environment and their role in microplastic generation throughout the materials' life cycle, from production and appli

Because paint particles consist of a resin (polymer) combined with one or more additives, they bear compositional similarities with microplastics. Despite these shared characteristics, however, paint particles are often undetected, deliberately overlooked or evade classification in the pool of micro-debris (all synthetic debris of < 5 mm in size), and in particular in the marine setting where an extensive body of microplastic literature exists. Accordingly, the present paper provides a critical insight into the physico-chemical properties, sources, distributions, behaviour and toxicity of paint particles in the marine environment. Paint particles contain a greater proportion of additives than plastics and, consequently, are more brittle, angular, opaque, dense, heterogeneous and layered than microplastics of equivalent dimensions. Land-based sources of paint particles, including deteriorating or disturbed coatings on roads and building, are transported to the ocean with other microplastics via urban runoff, water treatment facilities and the atmosphere. However, inputs of paint particles are enhanced significantly and more directly by the disturbance, erosion and weathering of coatings on coastal structures, boats and ships. Estimates of paint particle emissions to the marine environment vary widely, with calculated contributions to the total synthetic micro-debris input as high as 35%. Upper estimates are consistent with available (albeit limited) quantitative information on the relative abundance of paint particles amongst synthetic material captured by sea surface trawls and ingested by marine animals. Of greatest environmental concern is the high chemical toxicity of paint particles compared with similarly-sized microplastics and other synthetic debris. This results from the contemporary and historical use of high concentrations of hazardous inorganic additives in marine antifouling and land-based paints, and the relatively ready mobilisation of harmful ions, like Cu+/Cu2+, TBT+, Pb2+ and CrO4 2-, from the matrix. Recommendations arising from this review include greater use of particulate capturing devices, waste collection systems and recycling facilities during paint disturbance, raising awareness of the potential impacts of discarded paint amongst users, and alerting the microplastic community to the significance of paint particles and developing means by which they are isolated from environmental samples.