The objective of this study was to investigate the concentration distribution of indoor air pollutants in taxis and ships (passengers) which are frequently used for public transportation and recreational activities in South Korea. In addition, it aimed to assess air quality factors to establish and evaluate the health risks of exposure to polluted indoor air. Particulate matter (PM₁₀) concentrations were not affected by the number of passengers, time of day, and driving characteristics because there were only a few passengers (2 to 4 people) and the space was confined. In the ships, indoor air pollutants responded more sensitively to the operation characteristics depending on the time of sailing (i.e., anchoring and departure, movement of vehicles on the ship, movement of passengers, combustion in the shop, and ventilation) than to the number of people boarding and alighting. The carbon dioxide concentrations in different ship rooms did not vary according to season and degree of congestion; however, there were differences between different ships. These differences may result from the size, type, and operating characteristics of the ships. Volatile organic compounds (VOCs) and aldehydes in new taxis exceeded the standard levels during summer. VOC concentrations in ships were particularly high during summer when the outdoor temperature was high. Similar observations were made for other means of transportation. The risk assessment depended on the means of transportation and demonstrated that mortality risks due to PM₁₀ and excess carcinogenic and non-carcinogenic risks from VOCs and aldehydes were within safety levels.

Although plastic induces environmental damages, almost the consumption of poly(vinyl chloride) never stops increasing. Therefore, this work abstracted by two parts, first, synthesis of Schiff bases 1–4 compounds through the reaction of amino group with appropriate aromatic aldehyde, reaction of PVC with Schiff bases compounds 1–4 in THF to form a new modified PVC-1, PVC-2, PVC-3, and PVC-4. The structures of Schiff bases 1–4 and the modified PVC-1, PVC-2, PVC-3, and PVC-4 have been characterized by different spectroscopic analyses. Second, the influence of introducing 4-amino-1,2,4-triazole as a pendent groups into PVC chain investigated on photostability rules of tests. The modified polymers photostability investigated by observing indices (ICO, Iₚₒ, and IOH), weight loss, UV and morphological studies, and all results obtained indicated that PVC-1, PVC-2, PVC-3 and PVC-4 gave lower growth rate of ICO, IPO, and IOH through UV exposure time. The photostability are given as PVC-4 < PVC-3 < PVC-2 < PVC-1 from different mechanisms which suggested building on existence of 4-amino-1,2,4-triazole moieties in the polymer chain.

The attractive qualities of plastics lead us, around the world, to an enormous need for plastic goods, which results in their unsustainable overconsumption. Bio-based products are the core concept of circular economy, yet this sector suffers from the high cost of their production. In practice, biopolymers, such as polylactic acid (PLA), are still limitedly used, due to their expensiveness and not outstanding technological properties. A circular and sustainable solution would be to use waste from the food industry as filler that contributes to reduce the cost of PLA-based materials, thereby encouraging their widespread use. At the same time, this would be a circular approach to wisely upgrade food waste and prevent pollution. Ceramic food waste powder fillers from egg shells and from mussel shells were compounded with PLA at 180 °C to obtain composites, which contain an unprecedented high amount of filler, equal to 140 over 100 parts of PLA. We analyzed volatile organic compounds emitted from PLA and, for the very first time, from its composites via headspace-solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS). The molecular fingerprint of the volatiles comprises only three aldehydes, a ketone, and two lactides. Volatiles typical of fossil plastics, that are causative factors of hormone disruption or reproductive dysfunction, are effectively missing. Scanning electron microscopy, used to examine the structure of the composite, indicates that both the egg shells and the mussel shells are suitable fillers, in that they form a sufficiently strong interface with the polymer.

In this study, the recycling of gas flow was added to oxidize mixture (toluene and xylene) in the post-plasma catalysis (PPC) system, and the MnOx catalysts using impregnation method were used to further oxidize the VOC mixture. The circulation and catalysts were of enhancement for the plasma degradation on both toluene and xylene. The improvement of CO₂ selectivity and the reduction of NO, NO₂, and O₃ were 64.4%, 92.0%, 62.2%, and 51.9%, respectively. The fresh and used catalysts were characterized for the ozone decomposition and mixture degradation in the NTP-REC-CATAL system with the 15 wt% loading amount of catalysts. The results showed that OH groups, lattice oxygen, and manganese sites were potential and significant for the catalytic ability for O₃ and mixture conversion. Aldehyde was detected from FT-IR characterization after treating, which indicates that it is the main intermediate NTP-REC-CATAL process. The air plasma was employed to reactive catalytic activity.