The ozone layer forms a thin shield in the stratosphere, protecting life on Earth from harmful ultraviolet radiation. Emissions of ozonedepleting substances (ODS) used in many sectors (such as refrigeration, airconditioning, foams, and firefighting) destroy stratospheric ozone. Increased ultraviolet radiation from major depletion of stratospheric ozone can cause increases in skin cancer and cataracts, weaken the human immune systems, damage some agricultural crops, impact natural ecosystems, and degrade materials such as plastic. The Montreal Protocol on Substances that Deplete the Ozone Layer seeks worldwide phaseout of the production and consumption of ODS. Scientists confirmed that the protocol is working and that the ozone layer is on its way to recovery around the year 2050. Science and technology, including research at Antarctic stations proving that manufactured chemicals destroy stratospheric ozone and cause the Antarctic ozone hole, played important roles in the evolution and success of the protocol. Scientists provided early warning about the issue, discovered the Antarctic ozone hole, and linked it to CFC emissions and, along with nongovernmental organizations and the media, informed the public. The United Nations Environment Programme facilitated negotiations by governments. Science and technology panels of the protocol verified the performance of and facilitated periodical strengthening of the protocol. The scientific findings stimulated and motivated industry to innovation of alternatives to ODS. The protocol promoted universal participation, early action, continuous learning, and progressively tougher action. The protocol’s Multilateral Fund and its implementing agencies assisted developing countries through technology transfer, creation of national focal points and networks, training, and introduction of regulations and policies.

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Science and Diplomacy: Montreal Protocol on Substances that Deplete the Ozone Layer

Penetration of methyl bromide, sulfuryl fluoride, ethanedinitrile and phosphine into timber blocks and the sorption rate of the fumigants

Following the increasing international phasing out of methyl bromide for quarantine purposes, the development of alternative treatments for timber pests becomes imperative. The international accreditation of new quarantine treatments requires verification standards that give confidence in the effectiveness of a treatment. Probit-9 mortality is a standard for treatment effectiveness that has its origin in fruit fly research, and has been adopted by the United States Department of Agriculture for fruit flies and several other pests. Following this, the probit-9 standard has been adopted as a benchmark for many quarantine treatments worldwide. This article discusses aspects of the application of this concept for a range of timber pests. Problematic issues include the often small pest populations available for testing, the limits of modeling pest responses to a treatment in the absence of sufficient numbers for treatment verification, the species diversity of pests and host materials and the physical and chemical conditions of host material or treatment conditions. Where treatment verification by killing large numbers of individuals is impossible, data collected from small populations or under specific conditions must be interpreted with caution. We discuss possible alternative approaches to probit-9 as a treatment efficacy standard.

https://www.nrs.fs.fed.us/pubs/jrnl/2011/nrs_2011_schortemeyer_001.pdf

Appropriateness of probit-9 in the development of quarantine treatments for timber and timber commodities.

The mortality of naked Anoplophora glabripennis Motschulsky (Coleoptera: Cerambycidae) larvae exposed to ethanedinitrile (cyanogen; C2N2) varied with temperature, time of exposure, and dose of ethanedinitrile. The concentration x time (Ct) product of ethanedinitrile over a range of temperatures (4.4, 10.1, 15.6, and 20.1 degrees C) decreased with increasing temperature, for both 3- and 6-h exposures. The Ct products varied with time of exposure at different temperatures. The variations in mortality at different temperatures are described with a slope ratio (Y = [slope]6h/ [slope]3h). At different temperatures, the concentration of ethanedinitrile and the duration of exposure play different roles in killing A. glabripennis larvae. These results suggest the control of A. glabripennis larvae within wood is achievable.

/pdf/toxicity-of-ethanedinitrile-to-anoplophora-glabripennis-3chu6idw54.pdf

Toxicity of ethanedinitrile to Anoplophora glabripennis (Coleoptera: Cerambycidae) larvae.

BACKGROUND The sorption and desorption characteristics of methyl bromide (MB) were determined during and after fumigation of recently harvested pine (Pinus radiata D. Don) logs. The effects of dose (48 or 120 g m-3 ), degree of bark cover (0, 50 or 100%) and end-grain sealing (sealed or unsealed) on sorption and desorption were determined over time. RESULTS Sorption of MB was proportional to the dose applied and dependent on the amount of end-grain sealed. After 16 h, an average of 70.7 ± 2.5% of the initial concentration remained in the treated space when end-grains were sealed, whereas only 47.3 ± 2.5% remained when unsealed. During aeration, MB was released from logs, initially ranging from 2.8 to 8.8 g · h m-3 , depending on the treatment. The rate of desorption quickly decreased during aeration. CONCLUSION The surface area of a log is the most important factor influencing MB sorption and desorption rates, with greater surface area resulting in greater (de)sorption rates. Sorption data can now be combined with insect toxicity data to estimate a minimum effective dose of MB for further evaluation, while desorption data can be combined with fumigant plume modelling to assess worker safety. © 2016 Society of Chemical Industry.

G O'brien

Papers

Improved methodology for studying diffusion, sorption and desorption in timber fumigation