Atmospheric particle deposition and anthropogenic microparticles in tofu from plastic-waste-fueled small-scale industries in Sidoarjo, Indonesia

Plastic-waste combustion in small-scale food production may create particle-rich environments with potential for deposition onto exposed foods, yet paired environmental–food evidence remains limited. This cross-sectional study quantified atmospheric particle deposition and anthropogenic microparticles in tofu at 11 plastic-waste-fueled sites in Tropodo Village, Sidoarjo, Indonesia. Particles settling over 24 h were collected using passive dust-fall samplers, enumerated by stereomicroscopy, and classified as fibers, films, or fragments. One selected particle per deposition sample underwent ATR-FTIR screening. Tofu was analyzed using one 5g portion per site; pooled material from all 11 samples underwent ATR-FTIR screening, which could not confirm polymer identity in individual samples. Across sites, 221 deposited particles were counted: fibers 40.7%, films 32.6%, and fragments 26.7%. Deposition rates ranged from 1,401.27 to 4,713.38 particles m−2 d−1. Anthropogenic microparticles were visually detected in tofu from 9 of 11 sites (81.8%), at 0.00−2.20 particles g−1. Particle deposition was positively associated with tofu particle abundance (Pearson r=0.744,p=0.009), but the small sample and lack of particle-specific polymer matching preclude inference of direct air-to-food transfer. Without biomass-only or non-plastic-fuel reference sites, deposition cannot be attributed specifically to plastic-waste combustion. These findings identify the sampled facilities as high deposition production environments and support cleaner fuel substitution, protected food storage, contamination controls, and particle-level spectroscopic confirmation.Implications: This study identifies plastic-waste-fueled tofu production as a localized setting with substantial atmospheric particle deposition and co-occurring anthropogenic microparticles in exposed tofu. The findings suggest that waste-derived fuel use may contribute to environmental particle exposure and food-contact contamination, although source attribution is constrained by other local emissions. Practical risk-reduction measures include replacing plastic waste with cleaner fuels, separating combustion from tofu storage, improving dust and ash control, and protecting finished products. Future monitoring should integrate passive deposition sampling, contamination controls, and particle-level spectroscopic confirmation to strengthen source attribution and evaluate interventions.