Acute health effects of desktop 3D printing (fused deposition modeling) using acrylonitrile butadiene styrene and polylactic acid materials: An experimental exposure study in human volunteers.

3D printers are increasingly run at home. Nanoparticle emissions from those printers have been reported, which raises the question whether adverse health effects from ultrafine particles (UFP) can be elicited by 3D printers. We exposed 26 healthy adults in a single-blinded, randomized, cross-over design to emissions of a desktop 3D printer using fused deposition modeling (FDM) for 1 hour (high UFP-emitting acrylonitrile butadiene styrene [ABS] vs low-emitting polylactic acid [PLA]). Before and after exposures, cytokines (IL-1ß, IL-6, TNF-α, INF-γ) and ECP in nasal secretions, exhaled nitric oxide (FeNO), urinary 8-isoprostaglandin F2α (8-iso PGF2α ), and self-reported symptoms were assessed. The exposures had no significant differential effect on 8-iso PGF2α and nasal biomarkers. However, there was a difference (P < .05) in the time course of FeNO, with higher levels after ABS exposure. Moreover, indisposition and odor nuisance were increased for ABS exposure. These data suggest that 1 hour of exposure to 3D printer emissions had no acute effect on inflammatory markers in nasal secretions and urine. The slight relative increase in FeNO after ABS printing compared to PLA might be due to eosinophilic inflammation from inhaled UFP particles. This possibility should be investigated in further studies using additional biomarkers and longer observation periods.

Health effects of laser printer emissions: a controlled exposure study.

Ultrafine particles emitted from laser printers are suspected to elicit adverse health effects. We performed 75-minute exposures to emissions of laser printing devices (LPDs) in a standardized, randomized, cross-over manner in 23 healthy subjects, 14 mild, stable asthmatics, and 15 persons reporting symptoms associated with LPD emissions. Low-level exposures (LLE) ranged at the particle background (3000 cm-3 ) and high-level exposures (HLE) at 100 000 cm-3 . Examinations before and after exposures included spirometry, body plethysmography, transfer factors for CO and NO (TLCO, TLNO), bronchial and alveolar NO, cytokines in serum and nasal secretions (IL-1ß, IL-5, IL-6, IL-8, GM-CSF, IFNγ, TNFα), serum ECP, and IgE. Across all participants, no statistically significant changes occurred for lung mechanics and NO. There was a decrease in volume-related TLNO that was more pronounced in HLE, but the difference to LLE was not significant. ECP and IgE increased in the same way after exposures. Nasal IL-6 showed a higher increase after LLE. There was no coherent pattern regarding the responses in the participant subgroups or single sets of variables. In conclusion, the experimental acute responses to short but very high-level LPD exposures were small and did not indicate clinically relevant effects compared to low particle number concentrations.

Cow hair allergen concentrations in dairy farms with automatic and conventional milking systems: From stable to bedroom.

Bovine hair and dander are considered to be a notable risk factor for sensitization and allergic symptoms in occupationally exposed cattle farmers due to various IgE binding proteins. Farmers are suspected not only to be exposed during their work inside the stables but also inside their homes as allergens could be transferred via hair and clothes resulting in continued bovine allergen exposure in private areas. In recent years a new sensitive sandwich ELISA (enzyme linked immunosorbent assay) test has been developed to measure the cow hair allergen (CHA) concentration in dust. The aim of the present study was to determine the CHA concentration in airborne and settled dust samples in stables and private rooms of dairy cattle farms with automatic milking systems (AM) and conventional milking systems (CM), also with respect to questionnaire data on farming characteristics. For this purpose different sampling techniques were applied, and results and practicability of the techniques were compared. Dust sampling was performed in the stable, computer room (only AM), changing room, living room and bedroom (mattress) of 12 dairy farms with automatic milking systems (AM group) and eight dairy farms with conventional milking systems (CM group). Altogether, 90 samples were taken by ALK filter dust collectors from all locations, while 32 samples were collected by an ion charging device (ICD) and 24 samples by an electronic dust fall collector (EDC) in computer rooms (AM) and/or changing and living rooms (not stables). The dust samples were extracted and analyzed for CHA content with a sandwich ELISA. At all investigated locations, CHA concentrations were above the limit of detection (LOD) of 0.1 ng/ml dust extract. The median CHA concentrations in dust collected by ALK filters ranged from 63 to 7154 µg/g dust in AM farms and from 121 to 5627 µg/g dust in CM farms with a steep concentration gradient from stables to bedrooms. ICD sampling revealed median CHA contents of 112 µg/g airborne dust in the computer rooms of the AM farms and median CHA loads of 5.6 µg/g (AM farms) and 19.8 µg/g (CM farms) in the living rooms. Passive dust sampling by EDC was performed only at two locations in the AM group resulting in median CHA values of 116 µg/m(2) (computer room) and 55.0 µg/m(2) (changing room). Except for the stable samples the median CHA load was lower in AM farms compared to CM farms. The CHA contents of ALK filter samples were significantly correlated in most locations. Differences between the farming types were not significant. Although allergen transfer to the private area of the farmers has been found and results from several locations were correlated, differences in CHA concentrations were not significant with respect to questionnaire data such as the wearing of stable clothes in living room, free access of pets to stable and home, frequency of hair washing. All sampling techniques seem to being practicable for simple and effective CHA measurement.

Serum leptin and adiponectin levels and their association with allergic sensitization.

BACKGROUND: Obesity and respiratory allergies have increased in parallel in industrialized countries. We have recently shown an association between obesity and allergic sensitization whereby obesity diminished the protective effect of childhood farm contact. OBJECTIVE: To assess whether taking obesity into account allergic sensitization is associated with adipokine levels in blood and whether this effect is modified by childhood farm contact. METHODS: Serum samples of 231 adult participants (age 18-45 years) of the Lower Saxony Lung Study were analysed for leptin and adiponectin by ELISA. Subjects were elected to represent equal-sized groups with respect to obesity (<30 vs> or =30 kg/m(2)), childhood farm contact, specific IgE to ubiquitous allergens and sex. Multiple logistic regression models were adjusted for potential confounders. RESULTS: Leptin levels were positively related to the prevalence of sensitization (highest vs lowest quartile odds ratio 6.7, 95% confidence interval 2.0-22.4). For adiponectin levels, a weak, not statistically significant inverse association with sensitization was shown (highest vs lowest quartile 0.4, 0.2-1.1). The association between leptin and sensitization appeared to be more pronounced in subjects with farm contact; however, the effect modification was not statistically significant. CONCLUSION: These findings suggest that adipokines might be involved in the causal pathway between obesity and allergic sensitization.