Toward Sustainable Environmental Quality: Priority Research Questions for Asia

Environmental and human health challenges are pronounced in Asia, an exceptionally diverse and complex region where influences of global megatrends are extensive and numerous stresses to environmental quality exist. Identifying priorities necessary to engage grand challenges can be facilitated through horizon scanning exercises, and to this end we identified and examined 23 priority research questions needed to advance toward more sustainable environmental quality in Asia, as part of the Global Horizon Scanning Project. Advances in environmental toxicology, environmental chemistry, biological monitoring, and risk-assessment methodologies are necessary to address the adverse impacts of environmental stressors on ecosystem services and biodiversity, with Asia being home to numerous biodiversity hotspots. Intersections of the food-energy-water nexus are profound in Asia; innovative and aggressive technologies are necessary to provide clean water, ensure food safety, and stimulate energy efficiency, while improving ecological integrity and addressing legacy and emerging threats to public health and the environment, particularly with increased aquaculture production. Asia is the largest chemical-producing continent globally. Accordingly, sustainable and green chemistry and engineering present decided opportunities to stimulate innovation and realize a number of the United Nations Sustainable Development Goals. Engaging the priority research questions identified herein will require transdisciplinary coordination through existing and nontraditional partnerships within and among countries and sectors. Answering these questions will not be easy but is necessary to achieve more sustainable environmental quality in Asia. Environ Toxicol Chem 2020;39:1485-1505. © 2020 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

The Yung percutaneous mastoid vent: a medium-term follow-up study

BACKGROUND

I designed a percutaneous mastoid vent to provide permanent ventilation to the middle ear. The vent consists of an outer titanium tube that osseointegrates with the mastoid bone and an inner Teflon tube that protrudes into the mastoid antrum.

OBJECTIVE

To follow up all patients who had the mastoid vent inserted since 1995.

STUDY DESIGN AND SETTING

Retrospective study of 14 patients with mastoid vents inserted at the ear, nose, and throat clinic of a district general hospital.

PATIENTS

All patients had ventilation problems of the ear that failed to respond to conventional treatment. Three patients had persistent otitis media with effusion; 10 had completely collapsed eardrums; and 1 had failed tympanoplasty with recollapsed eardrum. INTERVENTION AND OUTCOME MEASURE: The mastoid vent extrusion rate, surrounding skin reaction, patency of the vent, and functional results were assessed with a follow-up period of 9 to 36 months.

RESULTS

Only 1 vent was extruded in a patient who had a previous cortical mastoidectomy. There was no dermatitis around any of the vents. All vents remained patent, and 9 of the 14 ears underwent successful ventilation. Four ears had adhesions within the mastoid antrum, mainly due to a previous cortical mastoidectomy. Six of 8 ears with intact ossicles also had improved hearing.

CONCLUSION

The percutaneous mastoid vent can provide medium-term ventilation to the middle ear.

Mastoid obliteration with hydroxyapatite--the value of high resolution CT scanning in detecting recurrent cholesteatoma

Mastoid obliteration carries a risk of enclosing cholesteatoma within the mastoid cavity. Using temporal bones obliterated with either muscle or hydroxyapatite granules, the value of high resolution CT scanning in the early detection of 'epithelial pearls' was studied. The results showed that scanning was effective in detecting small epithelial pearls within the cavity obliterated with hydroxyapatite, but not so effective when muscle was used. This is explained by the difference in the CT density between epidermoid cysts and hydroxyapatite allowing the cysts (dark shadows) to be identified easily within a white background. The authors also studied scans performed on 31 ears following mastoid obliteration with hydroxyapatite. There was no residual cholesteatoma in the obliterated area but there was an area of abnormality identified within the obliterated area in one patient due to a cholesterol granuloma.

The use of rigid endoscopes in cholesteatoma surgery

The existence of blind pockets in the middle ear during cholesteatoma surgery could compromise complete removal of the disease, e.g. from the sinus tympanum. The use of side-viewing rigid endoscopes in conjunction with the operating microscope to control and facilitate cholesteatoma removal during mastoid operation was studied. Ninety-two primary operations for cholesteatoma over a four-year period were examined. Over one-third (35.9 per cent) of these cases had cholesteatoma extended into the sinus tympanum. Sixty-four operations were small cavity mastoidectomy. The others were either canal wall reconstruction or primary obliteration following open cavity mastoidectomy. Although residual cholesteatoma was found in three patients, only one was in the middle ear. It is concluded from this study that side-viewing endoscopes could be very useful in cholesteatoma surgery.