The aim of the present study was to investigate usage patterns of mobile devices and their impact on users’ musculoskeletal system among working university students in Slovenia at the Faculty of Chemistry and Chemical Technology of the University of Ljubljana. An Internet-based survey was sent to students’ e-mail addresses and students provided information about usage patterns and reported on musculoskeletal pain (MSP) that may relate to mobile device usage in the past 12 months. A total of 535 students (63% females and 37% males) aged 18 years or older completed the survey and fulfilled the inclusion criteria. The results showed that the prevalence of MSP was 39.6%. Most musculoskeletal symptoms were reported in the back (57.1%) and shoulder (50%). Statistically significant differences in exposure to mobile devices and MSP between genders were found (p < 0.05). This study highlights the importance of knowledge of mobile device ergonomics among working students.

The purpose of the study was to determine the mechanical and ecotoxicological properties of mortars with differently shaped recycled PET plastics as a partial natural aggregate replacement and assess its environmental impact. Different methods were used for determining mechanical properties, while ecotoxicity tests with two types of plants were performed for the assessment of the ecotoxicological potential of mortars. Results of strength tests revealed that PET in mortars increased 28-day compressive strength by up to 3% and decreased flexural strength by up to 14% compared to conventional mortar. Ultrasonic pulse velocity and dynamic modulus of elasticity were lower in PET mortars, while XRD and SEM-EDS showed fewer hydration products in PET mortars. Duckweed ecotoxicity test results revealed that frond growth inhibition values in PETS and conventional mortar leachate (100 g L⁻¹) were around 50%, while root growth inhibition values did not exceed 40%. Mustard seed germination test results revealed root growth inhibition values in both mortar leachates were lower than 20%. Ecotoxicity tests showed that conventional and PET mortar were non-toxic to duckweed in aquatic environments and non-toxic to mustard seeds in terrestrial environments. Characterization of mortar leachates showed a significant increase in chloride, Ca, Si, and Ba content as potential causes for growth inhibition of both plants. Plastic waste reduction due to the potential use of PET in mortars confirmed that plastic waste could be completely eliminated and the global consumption of primary natural resources for concrete production reduced up to 4%. Such an approach could increase mortar sustainability.

For several decades, cement production has caused concerns about CO₂ emissions. As the production of concrete has increased over the years, the fact that cement is its key component additionally raises a concern. By partially replacing cement with waste material such as biomass waste biochar, the reduction in waste and the reduction of CO₂ emissions could be addressed at the same time but raises a concern about the ecotoxicological potential of biochar-containing cementitious composites. During their use, recycling and disposal of biochar-containing mortars could pose hazardous environmental impacts due to their exposure to rain and other environmental conditions. The aim of the study was to determine the early-age mechanical properties of mortars with 5%, 10%, and 15% biochar as partial cement replacement. The environmental impact of biochar-containing mortars in terms of carbon footprint reduction and ecotoxicological potential was addressed simultaneously. The biochar used was prepared from waste wood biomass as carpentry waste wood. Results showed that added biochar caused no significant changes in flowability and fresh density of fresh mortar mixture. The strength tests revealed mortars with 5% and 10% biochar had higher 3-day flexural strength, while only mortar with 5% biochar had higher 7- and 28-day compressive strength (4% and 6%) than the conventional mortar. The X-ray diffraction (XRD) analysis detected five main crystalline phases in biochar-containing mortars. SEM-EDS showed the strong embedment of biochar particles in cement paste. Ecotoxicological assessment based on acute toxicity tests with mortar leachates using duckweed and mustard seeds showed low toxicity of leachates with the highest inhibition values around 50%. The calculations of the total CO₂-equivalent emissions for selected mortars revealed mortars with biochar as partial cement replacement had lower CO₂-equivalent emissions than the conventional mortar and can contribute to carbon footprint reduction and at the same time to natural resource conservation.

Mobile device users often experience musculoskeletal discomfort due to the intensive use of these devices in static body postures. Prolonged sitting and standing at work and in free time are risk factors for various diseases and all-cause mortality. Prolonged static postures are the main cause of lower extremity discomfort. A systematic search of the articles was conducted in four different electronic databases. All selected papers were appraised using a critical appraisal tool. Fourteen studies were selected for the review. The prevalence of musculoskeletal complaints ranged from 0.4% to 72.9%. Mobile device-related lower extremity discomfort ranged from 0.4% to 9.6%. The most common body posture among mobile device users in the selected studies was sitting. There is some evidence on the association between lower extremity pain and mobile device use. Experts should take this review as a basis to provide appropriate and effective ergonomic measures, especially for working mobile device users.