Durable Plastic Goods: A Source of Microplastics and Chemical Additives in the Built and Natural Environments

Marine plastic pollution by single-use packaging is an emerging concern. However, more than half of all plastics manufactured are designed and utilized for longer-term uses (e.g., as indoor furnishings, insulation, electrical devices, conduits, and textiles). Such durable plastics are more likely to contain persistent, bioaccumulative, and toxic chemical additives (PBTs). Considerable additives and polymer fragments are released into enclosed indoor spaces over the service lives of these plastic products, with resultant human exposure, and then pass to wastewater treatment plants. However, globally only approximately half of all wastewaters receive any treatment. For affluent nations, efficiencies of removal of microplastics and PBTs of ≥90% are commonly quoted for effluents, but some wastewaters therein receive primary or less treatment. Regardless, PBTs and microplastics largely survive even sophisticated treatment, and most are deposited into settled solids. Such “biosolids” may then be repurposed to enrich soils due to their nutrient content. Associated contaminants may affect soil communities and later be dispersed via hydrologic and aeolian processes. To date, regulatory efforts have been insufficient to stem microplastic and additive emissions to air, water, and soils. Upgrading wastewater treatment to tertiary and excluding floating or primary settled solids from land-applied biosolids would substantially reduce releases of these contaminants.