We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Dermal and oral exposure risks to heavy metals from 3D printing metal-fill thermoplastics
AI summary Read the abstract
If you use 3D printing filaments that contain metal powder (like copper or bronze), touching the raw filament or letting it sit out in sunlight for a long time can cause it to release metal particles that your skin can absorb, especially copper. The good news: printed objects release much less metal than the raw spool, and simple precautions like wearing gloves and washing your hands after handling the filament can meaningfully lower your exposure risk.
Manufacturing advancements in polymer printing now allow for the addition of metal additives to thermoplastic feedstock up to 80-90 % by weight and subsequent printing on low-cost desktop 3D printers. Particles associated with metal additives are not chemically bound to the plastic polymer, meaning these particles can potentially migrate and become bioavailable. This study investigated the degree to which two human exposure pathways, oral (ingestion) and dermal (skin contact), are important exposure pathways for metals (copper, chromium, and tin) from metal-fill thermoplastics used in consumer fused filament fabrication (FFF). We found that dermal exposure to copper and bronze filaments presents the highest exposure risk due to chloride (Cl-) in synthetic sweat driving copper (Cu2+) release and dissolution. Chromium and tin were released as micron-sized particles < 24 μm in diameter with low bioaccessibility during simulated oral and dermal exposure scenarios, with potential to undergo dissolution in the gastrointestinal tract based on testing using synthetic stomach fluids. The rate of metal particle release increased by one to two orders of magnitude when thermoplastics were degraded under 1 year of simulated UV weathering. This calls into question the long-term suitability of biodegradable polymers such as PLA for use in metal-fill thermoplastics if they are designed not to be sintered. The greatest exposure risk appears to be from the raw filaments rather than the printed forms, with the former having higher metal release rates in water and synthetic body fluids for all but one filament type. For brittle feedstock that requires greater handling, as metal-fill thermoplastics can be, practices common in metal powder 3D printing such as wearing gloves and washing hands may adequately reduce metal exposure risks.
More Papers Like This
Release of the additive metals from 3 commonly used plastics during the degradation under the treatment of UV irradiation
AI summary Read the abstract
Researchers measured the release of heavy metals (chromium, manganese, iron, cobalt, copper, zinc, and lead) from three common plastics as they degraded under UV light. As the plastics broke down into microplastics, they released these metals — many of which are added as stabilizers or colorants during manufacturing. This shows that microplastics in the environment carry not just plastic fragments but also a cargo of toxic metals.
Assessment of the potential human health risk derived from metals associated to microplastics from recycled and biopolymer-based plastics
AI summary Read the abstract
Researchers assessed the human health risk from metals associated with microplastics derived from recycled PET and polylactic acid (PLA) biopolymers using oral bioaccessibility testing, finding that intrinsic metal content increased with recycling cycles and that both materials adsorbed metals from the environment, with bioaccessible metal fractions posing potential health risks.
Atmospheric microplastics as vectors of heavy metals and trace elements in tropical urban air: SEM–EDX and ICP–MS evidence from Metro Manila, Philippines
AI summary Read the abstract
Tiny plastic particles floating in the air over Manila can pick up metals like zinc, copper, and even toxic ones like lead and mercury, essentially acting as tiny hitchhiker rides for pollution. The good news: based on current levels, breathing these particles in doesn't appear to pose a meaningful health risk. Still, metal buildup on these particles increased sharply during the dry season, and as plastics break down into smaller, more easily inhaled pieces, scientists say this is worth continuing to watch.
Effects of chemical and natural ageing on the release of potentially toxic metal additives in commercial PVC microplastics
AI summary Read the abstract
Researchers aged commercial PVC microplastics under chemical and natural weathering conditions and measured release of potentially toxic trace metals added as stabilizers, finding that weathering significantly increased metal leaching rates, with cadmium and lead among the metals released.
Copper adsorption on microplastics: Investigating toxicity in an in vitro digestive environment
AI summary Read the abstract
Researchers analyzed how the presence of microplastics affects copper bioaccessibility and toxicity during in vitro digestion, testing naturally weathered particles as a realistic exposure model. Microplastics altered the bioaccessible fraction of copper, with implications for how co-ingested metals behave in the human gut.
Research digests by email
When a large batch of papers lands in the Atlas, we read through it and send a short write-up of what stood out.