[Risk assessment and toxicity effects of materials used during additive manufacturing with FDM technology]. / Ocena zagrozen i dzialanie toksyczne materialów stosowanych podczas drukowania przestrzennego w technologii FDM.

This paper discusses the potential of additive printing, the risks it poses to users' health (including 3D printer operators) and the effects of chemical substances released during the printing based on the available in vitro and in vivo studies. It was shown that substances emitted during printing with the commonly used acrylonitrile butadiene styrene filament in additive manufacturing might have carcinogenic, hepatotoxic and teratogenic effects, as well as toxic effect on the respiratory system. The latest research on the mechanism of formation of particles and volatile organic compounds during 3D printing, the parameters affecting their potential emission, and trends in reducing these hazards are indicated. The need for the design of more environmentally friendly and less emissive printing materials, as well as strategies for prevention and individual and collective protection measures are emphasized. Users of 3D printers should be familiar with all possible aspects of the threats associated with the printing process. Insufficient data on direct exposure to chemicals and particles released during the use of filaments makes it difficult to build awareness of safe working practices. Of particular concern is the health impact of emitted chemicals and particles from thermally treated materials in one of the most popular technologies for 3D printing, i.e., fused deposition modelling. Exposure of the users to, e.g., plasticizers added to filaments occurs through a variety of routes, by absorption through the skin, by inhalation or ingestion. Available epidemiological data, as well as current experimental works, indicate that such exposure is a high risk of cardiovascular diseases, atherosclerosis in adults, and cardiac problems and metabolic disorders in children. This review, by identifying potential risk factors, may contribute to reducing the health loss of printer users and improving working conditions and safety, especially in enterprises where additive manufacturing technology is used. Med Pr Work Health Saf. 2024;75(2):159-171.

Pressure Drop Dynamics during Filtration of Mixture Aerosol Containing Water, Oil, and Soot Particles on Nonwoven Filters.

The pressure drop dynamics during the filtration of three-component mixture aerosols are investigated and compared with two and single-component aerosols. The main area of interest is the effect of the addition of a small quantity of liquid (oil) and solid (soot) particles during the filtration of aerosol containing water mist. In addition, calculations of the change in filter mass during oil aerosol filtration have been carried out and compared with the experimental results. The new, improved filtration efficiency model takes into account a better coefficient fitting in the filtration mechanism equations. The limitations in the change in fibre diameter and packing density resulting from the filter loading have been implemented in the model. Additionally, the calculation model employs the fibre size distribution representation via multiple average fibre diameters. The changes in fibre diameter are dependent on each fibre's calculated filtration efficiency. The improved filtration model has been utilised to predict the mass change of the filters during the filtration of pure and mixture aerosols. The pressure drop calculation model based on changes in filter mass has been formulated. The model is then utilised to calculate pressure drop changes resulting from the filtration of the oil aerosol and water and oil mixture aerosol.

The association of maternal smoking and other sociobehavioral factors with dental caries in toddlers: A cross-sectional study.

Background: Severe early childhood caries (S-ECC) is a form of dental caries in toddlers, which can strongly affect general health and quality of life. Studies on factors that can contribute to the development of caries immediately after tooth eruption are sparse. The aim of this study was to assess the role of sociobehavioural factors and pre- and postnatal exposure to tobacco smoke in the aetiology of dental caries in children up to 3 years old. Methods: A cross-sectional study was conducted between 2011 and 2017 to assess oral health and teething in urban children 0-4 years of age. The number of teeth and surfaces with white spot lesions (d1,2), as well as decayed (d), missing (m), and filled (f) teeth classified according to ICDAS II was evaluated in a dental office setting. d1,2dmft and d1,2dmfs were calculated. Severe early childhood caries was diagnosed for d1,2dmfs > 0. Parents completed a self-administered questionnaire on socioeconomic factors, maternal health, course of pregnancy, child's perinatal parameters, hygiene and dietary practices, as well as maternal smoking during and after pregnancy. Data on children aged 12-36 months were collected and analysed statistically using the t-test, Spearman rank correlations and Poisson regression. Significance level was set at 0.05. Results: Dental caries was found in 46% of 496 children aged 12-36 months. Mean d1,2dmft and d1,2dmfs were 2.62 ± 3.88 and 4.46 ± 8.42, respectively. Tobacco smoking during and after pregnancy was reported by 8.9% and 24.8% of women, respectively. Spearman's rank correlation analysis confirmed a relationship between S-ECC and parental education, maternal smoking, bottle feeding, avoiding springy foods, number of meals, and the age of tooth brushing initiation. Pre- and postnatal exposure to tobacco smoke increased the risk of S-ECC especially in children in age 19-24 months. Maternal smoking was correlated with the level of education and dietary practices. Conclusion: Our study confirmed that prenatal smoking is associated with increased risk of severe-early childhood caries (S-ECC) while the association with post-natal smoking is also evident, the increase in risk is not statistically clear. Both maternal smoking and the child's tooth decay are associated with poor parental education and other improper oral health behaviours. The positive impact of quitting smoking on the oral health in children should be part of anti-smoking advice.

Vitamin D Supplementation, Characteristics of Mastication, and Parent-Supervised Toothbrushing as Crucial Factors in the Prevention of Caries in 12- to 36-Month-Old Children.

Severe early childhood caries (S-ECC), defined as any sign of smooth-surface caries in a child younger than three years of age, remains a serious health issue. The aim of this study was to indicate oral health behaviours related to S-ECC. The study surveyed parents (socio-economic and medical factors, oral health behaviours) and clinically examined children including non-cavitated d1,2/cavitated d ≥ 3 lesions. %S-ECC, and caries indices (d1,2 d ≥ 3 mft and d1,2 d ≥ 3 mfs) were calculated. Spearman's correlation and simple and multiple logistic regression were used to assess the relationships between various factors and S-ECC. A total of 496 children were examined. S-ECC occurred in 44.8%: d1,2 d ≥ 3 mft = 2.62 ± 3.88, d1,2 d ≥ 3 mfs = 4.46 ± 8.42. S-ECC was correlated with socio-economic factors, vitamin D supplementation, breastfeeding and using formula after the 18th month, and toothbrushing. Supplementation of vitamin D and toothbrushing tended to decrease the odds of S-ECC (OR = 0.49 (0.27−0.87); p = 0.016, OR = 0.46 (0.24−0.86) p = 0.015, respectively). Feeding exclusively with formula was observed to increase the odds of S-ECC (OR = 2.20 (1.29−3.76); p = 0.004). Consuming > three snacks daily (OR = 1.39 (0.97−1.98); p = 0.072) and the reluctance to eat resilient foods (OR = 1.63 (1.05−2.51); p = 0.028) were nullified by the confounding factors. Vitamin D supplementation, mastication of resilient food, breastfeeding in the first six months of a baby's life, and parent-supervised toothbrushing are factors in the prevention of caries in toddlers. Breast- and bottle-feeding after the 18th month of life, the reluctance to eat solids, lack of vitamin D supplementation, hygienic neglect, and delay in introducing oral health behaviours may contribute to the development of caries in toddlers.

The Influence of Air Humidity on the Output Signal from an Ionization Smoke Detector in the Presence of Soot Nanoparticles.

In 2019, the European Committee for Standardization (CEN) initiated work on the preparation of a strategy for air quality monitoring at workplaces. The aim was to determine the concentrations of nano-objects and their aggregates and agglomerates (NOAA) by means of direct measurements using low-cost sensors. There is a growing need for low-cost devices that can continuously monitor the concentrations of nanoparticles, and that can be installed where nanoparticles are used or created spontaneously. In search of such a device, in this study, a smoke detector with an ionization sensor was tested. The aim of the research was to investigate the response of the analog output signal with respect to changes in environmental parameters such as the relative humidity of air. The research was conducted in controlled laboratory conditions, and the results confirmed that an ionization detector could be used to measure the concentrations of nanoaerosols. The modified smoke detector detected soot particles smaller than 100 nm. The linear regression line was calculated for the relative humidity dataset and had a slope coefficient of -1.214 × 10-4; thus, the value of the output signal was constant during the experiment. The dependence on air temperature was approximated by a second-degree curve, with a slope coefficient of -8.113 × 10-2. Air humidity affected aerosol concentrations, which may be related to surface modification of nanoparticles.