Evaluation of the effect of photoplethysmograms on workers’ exposure to methyl bromide using second derivative

Abstract

Methyl bromide (MB) is worldwide the only effective fumigant heavily used for quarantine pre-shipment treatment and has a critical use exemption for soil fumigations due to its excellent permeability and insecticidal effect. However, MB should be replaced as it is an an ozone-depleting substance and also highly toxic to humans. Recently, MB has been shown to be hazardous even for asymptomatic workers, affecting their central and autonomic nervous systems. However, the effects of MB exposure on vascular health have not been explored. This study aimed to determine whether MB affects the arterial system of asymptomatic workers. We measured the second derivative of the photoplethysmogram (SDPTG) indices, which are indicators of vascular load and aging, and urinary bromide ion (Br−) concentrations in 44 fumigators (study group) and 20 inspectors (control group) before and after fumigation. In fumigators, the mean values of post-work SDPTG indices (b/a, c/a, d/a, e/a, and SDPTG aging index) and Br− levels were significantly changed compared to their pre-work values (p < 0.05), indicating a negative effect on their cardiovascular health. In contrast, SDPTG indices and Br− levels in inspectors did not show any differences before and after work. All SDPTG indices except c/a showed significant correlations with Br− levels in all individuals (p < 0.05). In conclusion, the Br− levels and SDPTG indices of fumigators varied after MB work, and they experienced negative effects on their health despite being asymptomatic.

Sulfuryl Fluoride Fumigation as a Quarantine Treatment for the Control of Reticulitermes speratus Kolbe (Blattodea: Rhinotermitidae) in Wood

“…MB was classified as an ozone-depleting substance under the Montreal Protocol, which was established in 1989 [ 10 ], and the International Plant Protection Organization (IPPC) recommended its replacement and reduction [ 11 ]. Furthermore, MB is a highly toxic pesticide, and recent studies have reported that, even without obvious symptoms, workers experience negative effects in relation to their central nervous, autonomic nervous, and vascular systems [ 12 , 13 , 14 ]. Korea has developed MB alternatives such as phosphine (PH 3 ) and ethyl formate (EF), which have been used in quarantine procedures since 2011, and ethanedinitrile (EDN), which was introduced in 2019 [ 15 , 16 , 17 ].…”

Ethyl Formate Fumigation for Controlling Two Major Aphid Pests, Aphis spiraecola and Aphis gossypii, on Passion Fruit, from Cultivation to Post-Harvest Storage

“…Consequently, there has been a need for frequent fumigation with methyl bromide (MB) in these countries [ 7 ]. However, MB negatively impacts the value of the produce [ 8 ] and the health of the workers [ 9 , 10 , 11 ], making it necessary to replace MB with safer fumigants. Moreover, when passion fruits are exported, the pests in the fruits must be controlled before export.…”