Towards the improvement of UN N.5 test method for the characterization of substances which in contact with water emit flammable gases

This paper deals with a sensitivity analysis of main parameters affecting the measurement of the gas flowrate emitted during testing substances for their potential to emit flammables gases in dangerous quantities where in contact with water, according to the UN N.5 test procedure. UN N.5 is described in the Manual of Tests and Criteria of United Nations (part of the Orange Book) (ONU Manual of Test and Criteria, 2008), serving both applications of international transport regulations as well as classifications of dangerous substances according to Globally the Harmonized System (GHS) and the derived regulation applying in the EU known as “CLP” Regulation (Regulation (EC) No 1271/2008). The main reason that justifies the present research is that the measurement of emitted gases is highly critical in the final classification resulting from the interpretation of the test results. Moreover, that idea has been raised to adapt the UN N.5 test protocol for classifying, in the future, substances that by contact with water would emit dangerous quantities of toxic gases.Experiments have been carried out to cover the analysis of the influence of ambient temperature, overall volume of glassware, nature of aqueous media, mass sample and sample-to-liquid mass ratio, since such parameters are not fixed within any defined range in the UN N.5 test procedure. The influence of the flow rate measuring device was also considered. Results confirm that the above mentioned parameters may play a significant role to such an extent as to finally alter the final classification resulting from the testing. Guiding principles have also been derived from our measurements and observations towards an improved and more robust UN test protocol in the future.     

Research on simultaneous impact of hand-arm and whole-body vibration

This article presents the results of laboratory tests on the combined effect of whole-body vibration (WBV) and hand-arm vibration (HAV). The reactions of subjects exposed to various combinations of vibration were recorded. The vibrotactile perception threshold (VPT) test identified changes caused by exposure to vibration. Ten male subjects met the criteria of the study. There were 4 series of tests: a reference test and tests after exposure to HAV, WBV, and after simultaneous exposure to HAV and WBV. An analysis of the results (6000 ascending and descending VPTs) showed that the changes in VPTs were greatest after simultaneous exposure to both kinds of vibration. The increase in VPT, for all stimulus frequencies, was then higher than after exposure to HAV or WBV only.     

Self-assessment of hearing status and risk of noise-induced hearing loss in workers in a rolling stock plant

Noise measurements and questionnaire inquiries were carried out for 124 workers of a rolling stock plant to develop a hearing conservation program. On the basis of that data, the risk of noise-induced hearing loss (NIHL) was evaluated. Additionally, the workers' hearing ability was assessed with the (modified) Amsterdam inventory for auditory disability and handicap, (m)AIADH. The workers had been exposed to noise at A-weighted daily noise exposure levels of 74-110 dB for 1-40 years. Almost one third of the workers complained of hearing impairment and the (m)AIADH results showed some hearing difficulties in over half of them. The estimated risk of hearing loss over 25 dB in the frequency range of 3-6 kHz was 41-50% when the standard method of predicting NIHL specified in Standard No. ISO 1999:1990 was used. This risk increased to 50-67% when noise impulsiveness, coexposure to organic solvents, elevated blood pressure and smoking were included in calculations.     

Winter arsenic pollution in 10 forest ecosystems in the mountainous border regions of the Czech Republic

Environmental Science and Pollution Research - Arsenic (As) concentrations and deposition fluxes were measured in snow and rime at 10 mountain-top sites near the borders between the Czech Republic...     

Ecotoxicology of alpine streams in the West Carpathians—Alpine Bullhead (Cottus poecilopus) and high mountain flash flood effects

Environmental Science and Pollution Research - Flash floods represent a serious threat to wildlife, water biota, and human life in pre-alpine regions, particularly in recent historical memory. The...     

Is ionizing radiation effective in removing pharmaceuticals from wastewater?

Environmental Science and Pollution Research - Wastewater and effluent discharges are the main causes of receiving water body pollution and important challenges in water quality management. Among...     

Elevation of biochar application as regulator on denitrification/NH3 volatilization in saline soils

Environmental Science and Pollution Research - Denitrification and NH3 volatilization are the main removal processes of nitrogen in coastal saline soils. In this incubation study, the effects of...     

Environmental Impact Assessment of Polylactide(PLA)/Chicken Feathers Biocomposite Materials

The aim of this study is to analyse the environmental impacts (EIs) of the process of preparation of new biocomposite materials obtained from polylactide (PLA) and chicken feathers (CFs). Two CFs stabilization methods and different percentages of CFs have been studied. The EIs of these new composites were compared to the impact of virgin PLA. Cradle-to-gate life cycle inventories were assessed for 0–35% v/v of CFs in a CFs/PLA biocomposite. Two CFs stabilization processes, autoclave and surfactant, were tested and compared with the aim to prioritize one of them from the environmental point of view. A composite plate of 184?×?184?×?2.2 mm³ was defined as the functional unit. Autoclave stabilization process exhibited lower environmental impact compared with surfactant stabilization process mainly due to both the lower requirements of electricity and water and the reduced pollution loads of the generated wastewater. Thus, the autoclave process was selected as the standard method when comparing the EIs of the proposed CFs/PLA biocomposites. In this sense, the addition of CFs to PLA matrix proportionally reduces all the EIs compared to pure PLA due to the replacement of PLA with CFs. This behaviour can be explained because the PLA production accounts for the 99% of the impact of the biocomposite. Consequently, CFs conveniently stabilized might be an alternative raw material to prepare CFs/PLA biocomposites with less environmental impact compared to pure PLA.