Global atmospheric distribution of microplastics with evidence of low oceanic emissions

Abstract

Recent investigations based on sea–air transfer physical mechanistic studies suggest that the global ocean’s contribution to atmospheric microplastic emissions is significantly lower (four orders of magnitude) than previously estimated. However, no atmospheric models or observations have yet validated this lower emission flux, leaving the analysis without adequate validation and practical significance. Here, we provide quantitative estimates of the global atmospheric microplastic budget based on this reduced oceanic flux. Our model aligns well with observed atmospheric microplastic concentrations and suggests that the ocean functions more as a sink than a source, contributing only ~0.008% of global emissions but accounting for ~15% of total deposition. This challenges the previous view of the ocean as the primary atmospheric microplastic source, urging a reassessment of pollution mitigation strategies.