Application of ozone gas for decontamination of nucleoside anticancer drugs

Recycling COVID-19 health care wastes in bitumen modification: a case of disposable medical gloves

Disposable medical gloves (DMGs) have long been used to mitigate the risk of direct exposure to diverse microorganisms and body fluids; hence, they are a critical weapon to protect patients and healthcare staff from infectious diseases. Measures to control the spread of COVID-19 have sparked the production of an excessive number of DMGs, most of which are eventually being disposed of in landfills. Untreated DMGs in landfills do not only pose a direct risk of transmitting coronavirus and other pathological germs but also pollute air, water, and soil dramatically. As a healthier alternative, recycling discarded polymer-rich DMGs into bitumen modification is considered to be a prospective waste management strategy applicable to the asphalt pavement industry. In this study, this conjecture is tested by examining two common DMGs - latex gloves and vinyl gloves - at four different percentages (1%, 2%, 3%, and 4% by weight). The morphological characteristics of DMG-modified specimens were inspected by using a high-definition scanning electron microscope (SEM) equipped with an energy dispersive X-ray analyzer (EDX). A wide range of laboratory tests including penetration, softening point temperature, ductility, and elastic recovery were undertaken to evaluate the impact of waste gloves on the conventional engineering properties of bitumen. Moreover, viscoelastic behavior and modification processing were studied by conducting the dynamic shear rheometer (DSR) test and the Fourier transform infrared spectroscopy (FTIR) analysis. Test results have revealed the outstanding potential of recycled DMG waste for modifying neat asphalt binder. More specifically, bitumens modified with 4% latex glove and 3% vinyl glove were seen as capable of superiorly withstanding permanent deformations caused by heavy axle loads at high service temperatures. Furthermore, it has been shown that 1.2 tons of modified binder would embed approximately 4000 pairs of recycled DMGs. This study shows that DMG waste can be used as a viable modifier, which would help open a new avenue for mitigating the environmental pollution arising from the COVID-19 pandemic.

Study on the Use of Ozone Water as a Chemical Decontamination Agent for Antineoplastic Drugs in Clinical Settings

The exposure of healthcare workers to antineoplastic drugs in hospitals has been recognized to be harmful. To minimize the risk of exposure, the removal of these drugs from work environments, such as compounding facilities, has been recommended. In our previous paper, the degradation and inactivation efficacy of ozone water, which is being introduced into Japanese hospitals as a chemical decontamination agent, was reported for its effects on typical antineoplastic drugs (gemcitabine, irinotecan, paclitaxel). This article aims to further investigate the efficacy of ozone water for eight antineoplastic drugs to clarify its application limitations. A small amount (medicinal ingredient: typically ca. 1.5 μmol) of formulation containing 5-fluorouracil, pemetrexed, cisplatin, oxaliplatin, cyclophosphamide, ifosfamide, doxorubicin, or docetaxel was mixed with 50 mL of ozone water (~8 mg/L), and the resulting solutions were analyzed by high-performance liquid chromatography over time to observe the degradation. Consequently, the ozonation was overall effective for the degradation of the drugs, however this varied depending on the chemical structures of the drugs and additives in their formulations. In addition, after the parent drugs were completely degraded by the ozonation, the degradation mixtures were subjected to 1H nuclear magnetic resonance spectroscopy and evaluated for mutagenicity against Salmonella typhimurium strains and cytotoxicity against human cancer cells. The degradation mixtures of cisplatin and ifosfamide were mutagenic while those of the other drugs were non-mutagenic. Further, the ozonation resulted in clear decreases of cytotoxicity for 5-fluorouracil, oxaliplatin, and doxorubicin, but increases of cytotoxicity for pemetrexed, cisplatin, cyclophosphamide, and ifosfamide. These results suggest that the ozone water should be restrictedly used according to the situation of contamination in clinical settings because the ozonation enhances toxicity depending on the drug even if degradation is achieved.

Degradation and inactivation efficacy of ozone water for antineoplastic drugs in hospital settings

PURPOSE

Occupational exposure to antineoplastic drugs in hospital settings is recognized to be hazardous, and as such environmental decontamination including degradation and inactivation of such drugs is recommended. To data, although various agents such as oxidants have been reported to be useful for decontamination, simpler, safer, and more convenient methods are required. In this study, the degradation and inactivation efficacy of ozone water, which has newly been introduced for decontamination of antineoplastic drugs in spills, was investigated for formulations of gemcitabine, irinotecan, and paclitaxel.

METHODS

Antineoplastic formulations (medicinal ingredient: ∼1.5 μmol) were mixed with 50 mL of ozone water (>4 mg/L). The reactions were monitored by high-performance liquid chromatography, and the degradation mixtures were analyzed by ¹H nuclear magnetic resonance spectroscopy in order to obtain the structural information of the degradation products. The formulations of gemcitabine and irinotecan and those degradation mixtures were evaluated for their mutagenicity using the Ames test and cytotoxicity against human cancer cells.

RESULTS

gemcitabine and irinotecan were found to be readily degraded by the ozone treatment, and their active sites were suggested to be degraded. In contrast, paclitaxel was hard to be decomposed, possibly owing to the consumption of ozone by the polyoxyethylene castor oil added as a pharmaceutical additive of the formulation. No significant mutagenic changes of Salmonella typhimurium strains used for the Ames test were observed for the samples within the concentration ranges examined. The ozone treatment showed obvious increases in cell viability for gemcitabine formulation, and mild increases for irinotecan formulation.

CONCLUSIONS

Ozone water was shown to be effective as a decomposition agent for the antineoplastic drug formulations examined, although the efficacy depends on the chemical structures of the drugs and the pharmaceutical additives. It was also suggested that ozone treatment has a tendency to decrease the toxicity of the antineoplastic drug formulations. As such, further studies are required in order to clarify the effects and application limitations of ozone water.

Review of Current Healthcare Waste Management Methods and Their Effect on Global Health

Healthcare is a rapidly growing industry as medical treatments become more sophisticated, more in demand due to increasing incidence of chronic disease and more widely available worldwide. This booming industry is also creating more waste than ever before and, as such, there is a growing need to treat and dispose of this waste. Healthcare waste (HCW) disposal includes a multitude of disposal methods, including incineration, landfilling and chemical treatments. These rudimentary methods and their growing use present their own problems that negatively impact both the environment and, in turn, damage public health, thus contributing to a global healthcare crisis. The aim of this review was to examine the current HCW disposal methods in place and the harmful effects they have on the environment and on public health. The findings accumulated in this review demonstrate a heavy reliance on basic, low tech HCW disposal techniques and uncovered the negative impacts of these methods. There is a notable lack of employment of "greener" HCW disposal methods on a largescale due to cost, access and feasibility. Despite innovations in HCW disposal, there is no scalable, global green solution at present. Further, the review highlights that global health consequences of HCW disposal methods often differ depending on how developed the country is.