Recently, MCTL (Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education) published the results of a collaborating study, named “Fumigant methyl iodide can methylate inorganic mercury species in natural waters”, in Nature Communication
(http://www.nature.com/ncomms/2014/140819/ncomms5633/full/ncomms5633.html).
This study was conducted by 5 researchers from US and China. Yanbin Li, an associate professor of MCTL, was the second author of the paper. Yong Cai, one of the two corresponding authors, is a professor from Florida International University and he is also a guest professor of MCTL “111” program.
Methylmercury (MeHg) is one of the most concerned and widespread contaminants in the environment. Methylation of mercury by microorganisms has been deemed to be the main source of MeHg in aquatic environments. By using both Hg and hydrogen (CD3I) stable isotope addition techniques, the authors found that fumigant methyl iodide can methylate inorganic mercury to MeHg under sunlight. This finding refines the pathways of Hg methylation in the environment and significantly improves the understanding of MeHg production in the environment.
Methyl iodide has recently been registered as a fumigant in many countries (US, Japan, etc.). This finding suggests that a more comprehensive risk assessment should be performed to confirm the safety of using CH3I as fumigant.
