“Microplastics and Polymers in Construction Materials: Sources, Fate, and Structural/Environmental Impacts”

Construction practices increasingly rely on polymer additives and recycled plastics to enhance durability and reduce material footprints, but these benefits carry environmental and structural tradeoffs. This review synthesizes evidence that polymer fragments and fibers generated during manufacturing, placement, maintenance, and demolition rapidly produce microplastic particles that partition among airborne dust, surface deposits, and stormwater runoff. We present a practical sampling framework and compare extraction and spectroscopic identification methods, highlighting strengths and limitations of density separation, controlled digestion, μ FTIR, Raman, and microscopy approaches for size classes and matrices common to building sites. Combining field studies and modeling, we map fate and transport pathways from site scale emission hotspots to downstream retention basins and sediments, showing how particle size, density, and biofouling control whether fragments remain airborne, move with surface flow, or deposit in soils and sediments. We summarize structural consequences of intentional and unintentional polymer inclusion, noting that well engineered fiber additions can improve flexural behavior while heterogeneous plastic fragments often increase porosity and reduce compressive strength and durability under freeze thaw and chemical exposure. We review evidence for additive leaching, documenting that plasticizers, stabilizers, and some flame retardants can mobilize into stormwater and porewater at concentrations that are environmentally relevant in poorly flushed settings. Human and ecological exposure pathways are evaluated: occupational airborne loads during cutting and demolition are high, community downwind exposures are measurable, and aquatic organisms show adverse responses to particle and chemical mixtures in laboratory tests. Life cycle assessments paired with durability metrics reveal context dependent tradeoffs between embodied carbon benefits and pollution risks when plastics are incorporated into materials. Finally, we offer a tiered mitigation strategy: source control, enclosed handling, targeted sampling, engineered on site controls, and procurement standards to reduce emissions and protect workers and receiving ecosystems. The synthesis provides practical research priorities, monitoring guidance, and policy considerations to make construction practices both resilient and environmentally responsible. We recommend standardized reporting, recovery testing, combined particle and chemical monitoring, and interdisciplinary collaboration to close knowledge gaps and guide regulation. Adopting these measures will reduce environmental loads and enhance material longevity. and public health.