Microplastics and human health risks: toward evidence-based policy and regulation in the Philippines
Microplastics (MPs) have emerged as pervasive environmental contaminants with increasing relevance to human exposure and public health. While global evidence on MP occurrence and exposure is rapidly expanding, country-specific syntheses that translate environmental findings into policy-relevant insights remain limited. In the Philippines, no national policy explicitly mandates systematic monitoring or regulation of microplastics across environmental, food, or atmospheric systems. To address this gap, this qualitative meta-synthesis integrates evidence from Philippine studies examining MP occurrence across environmental matrices, biological samples, and experimental toxicological investigations to evaluate potential human exposure pathways and regulatory implications. Across multiple regions of the country, MPs are consistently detected in matrices directly associated with inhalation and dietary intake, including ambient air, road dust, freshwater and marine environments, and commonly consumed seafood and aquaculture products. Fibers and fragments dominate most environmental matrices, with polymers such as polyethylene, polypropylene, polyethylene terephthalate, and polyester frequently identified, indicating contributions from packaging materials, textiles, and urban plastic waste sources. Although direct epidemiological evidence linking MP exposure to human health outcomes remains limited, the convergence of widespread environmental occurrence, plausible exposure pathways, mechanistic evidence of toxicity, and food-chain contamination highlights the need for precautionary regulatory responses. This review provides a policy-oriented framework that emphasizes standardized monitoring protocols, upstream source-control strategies, the integration of microplastics into food safety systems, and the explicit recognition of inhalation pathways within national environmental and public health governance.