Chemical emissions from building materials may significantly impact indoor air quality and potentially human health, since individuals spend most of their time indoors. With rising global temperatures and more frequent heatwaves, building materials’ resilience becomes more crucial for indoor air quality and structural integrity. However, the effects of temperature rise on building material emissions are not systematically studied. This study investigates the effect of a moderate temperature rise on the volatile organic compound (VOC) and aldehyde emissions of eighteen commonly used building materials, such as engineered hardwood, nylon carpet, terrazzo flooring, and acoustic tile, at two elevated yet realistic temperature points. The chemical emissions were collected using a micro-chamber setup and analyzed using thermal desorption/gas chromatography/mass spectrometry and high-performance liquid chromatography. The results showed that 78% of the materials tested demonstrated increased chemical emissions at higher temperatures. Wood-flooring materials showed statistically significant increases in formaldehyde at elevated temperatures, which could be associated with health risks. Eight of the tested materials, particularly those used in large surface area applications, showed significant increases in emissions at increased temperatures, and half of these were labeled as “low-VOC”. These findings may inform the updating of building standards and third-party certification with respect to temperature variation when assessing building material emissions. This research aims to provide a comprehensive understanding of VOC and aldehyde emissions at emerging indoor environmental conditions due to extreme heat climate scenarios.

Gene mutations linked to diseases like cancer may be caused by exposure to environmental chemicals. The X-linked phosphatidylinositol glycan class A (PIG-A) gene, required for glycosylphosphatidylinositol (GPI) anchor biosynthesis, is a key target locus for in vitro genetic toxicity assays. Various organisms and cell lines may respond differently to genotoxic agents. Here, we compared the mutagenic potential of directly genotoxic ethyl methane sulfonate (EMS) to metabolically activated pro-mutagenic polycyclic aromatic hydrocarbons (PAHs). The two classes of mutagens were compared in an in vitro PIG-A gene mutation test using the metabolically active murine hepatoma Hepa1c1c7 cell line and the human TK6 cell line, which has limited metabolic capability. Determination of cell viability is required for quantifying mutagenicity. Two common cell viability tests, the MTT assay and propidium iodide (PI) staining measured by flow cytometry, were evaluated. The MTT assay overestimated cell viability in adherent cells at high benzo[a]pyrene (B[a]P) exposure concentrations, so PI-based cytotoxicity was used in calculations. The spontaneous mutation rates for TK6 and Hepa1c1c7 cells were 1.87 and 1.57 per million cells per cell cycle, respectively. TK6 cells exposed to 600 µM and 800 µM EMS showed significantly higher mutation frequencies (36 and 47 per million cells per cell cycle, respectively). Exposure to the pro-mutagen benzo[a]pyrene (B[a]P, 10 µM) did not increase mutation frequency in TK6 cells. In Hepa1c1c7 cells, mutation frequencies varied across exposure groups (50, 50, 29, and 81 per million cells per cell cycle when exposed to 10 µM B[a]P, 5-methylcholanthrene (5-MC), chrysene, or 16,000 µM EMS, respectively). We demonstrate that the choice of cytotoxicity assay and cell line can determine the outcome of the Pig-A mutagenesis assay when assessing a specific mutagen.

Material extrusion 3D printing has been widely used in industrial, educational and residential environments. However, the associated emissions and exposure health impacts need to be evaluated, especially for the new and emerging filament materials. This study characterized particle and chemical emissions from 3D printing using five different metal composite filaments, which contain over 90% (by weight) of metal powder blended with polymer binders. The emission characterization was conducted using an exposure chamber following a standard testing method. Real-time particle measurements showed that particle emission rates ranged from 8 × 10⁹ to 2 × 10¹¹ particles/h for particle number and 200 to 1400 µg/h for particle mass. Over 98% of the emitted particles were smaller than 1 µm, which poses an inhalation hazard. Inductively coupled plasma–mass spectrometry analysis detected manganese, copper, zinc, and selenium in emitted particles from all filaments. However, metal powder in raw filaments tended not to be transferred into particle emissions, resulting in the total metals (and metalloids) accounting for 0.07% to 0.95% of emitted particle mass. Sorbent tube sampling and analytical analyses showed various volatile organic compounds emitted during printing, including hydrocarbons, alcohols, aldehydes, and aromatic compounds. Overall, metal composite filaments generated lower levels of volatile organic compounds (VOCs) compared to thermoplastic polymer filaments; in addition, the emitted VOC compositions differed. Organic chemicals associated with metal composite filament emissions included formaldehyde, benzaldehyde, acetaldehyde, naphthalene, and trimethylbenzene, exposure to which may cause irritations or other adverse health impacts. This study estimated personal exposure to hazardous components assuming a person is close to the printer with low ventilation to represent an acute worst-case exposure scenario. Modeled personal exposure to emissions showed potential exceedances of exposure to fine (PM_2.5) and coarse (PM₁₀) particulate matter, arsenic, manganese, formaldehyde, caprolactam, acetaldehyde, and naphthalene compared to reference levels. A modeled office room with ventilation showed reduced exposure levels by up to two orders of magnitude, assuming the same emission source. Users can avoid close proximity to an operating printer and increase dilution through larger room volumes and higher air change rates to reduce potential inhalation exposures at given printing conditions.