Variations in methyl bromide concentration with distance and time during quarantine fumigation

Min-Goo Park,Chung Gyoo Park,Hyoung-Ho Mo,Dong-Chul Gu,Young-Seoub Hong

doi:10.1007/s10661-021-09154-3

Abstract

Methyl bromide (MB) is a highly toxic and ozone-depleting substance and should be replaced. Worker exposure to high MB concentrations during fumigation has been previously reported. However, variations in MB concentration as a function of distance from fumigated objects or of time after degassing have not been reported so far. In this study, air samples were collected at various distances from fumigated objects (oranges, wood in containers, and wood in tarpaulin) during injection and degassing and analyzed via gas chromatography according to the Occupational Safety and Health Agency method. In addition, MB concentrations were directly measured over time using a gas detector during degassing. Non-linear regression analysis of the logarithmically transformed data indicated a clear decrease in MB concentration with distance as well as time. Non-linear regression models were constructed to describe the decrease in MB concentration with distance from the objects and with time during degassing (P < 0.05 for all models). The results of this study could aid in establishing appropriate safety guidelines, and hence, in preventing risks related to MB exposure.

Highlights

Methyl bromide (MB) has been used as a disinfectant for removing pests in trade commodities as wellY.-S
We propose a regression model describing the relationship between MB concentration and the distance from the fumigated objects as well as time from the commencement of degassing
The MB concentration decreased with distance during both the injection and degassing processes for all three treated commodities, namely, oranges in containers, woods in containers, and woods in tarpaulin (Table 1)

Summary

Introduction

Methyl bromide (MB) has been used as a disinfectant for removing pests in trade commodities as well. The fumigant is absorbed mostly via respiration and causes lung damage, cytotoxicity, genotoxicity, visual disturbance, and various other toxic effects in the human body (Baur et al, 2015; Deschamps & Turpin, 1996; Preisser et al, 2012; Suwanlaong & Phanthumchinda, 2008) Neurological disorders such as nausea, vomiting, and dizziness appear to be the most prevalent effects of MB exposure and are caused by the presence of MB metabolites such as methyl phosphate in cells (Agency for toxic substances and disease registry (ATSDR), 2018; Bulathsinghala & Shaw, 2014). The studies were undertaken for risk assessment within various fumigation enclosures, such as containers, or during various fumigation processes, such as dispersion and degassing These studies did not provide a clear explanation as to why workers are exposed to such high MB concentrations and how such exposure can be avoided. In terms of ensuring worker safety, for the distance required between the fumigated objects and the workers as well as the time required between fumigation completion and resumption of subsequent work are provided

Materials and methods

Results and discussion

Conclusion