Methyl chloride and methyl bromide emissions from baking: an unrecognized anthropogenic source
Number of Authors: 4
2016 (English)In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 551, 327-333 p.Article in journal (Refereed) Published
Methyl chloride and methyl bromide (CH3Cl and CH3Br) are the largest natural sources of chlorine and bromine, respectively, to the stratosphere, where they contribute to ozone depletion. We report the anthropogenic production of CH3Cl and CH3Br during breadbaking, and suggest this production is an abiotic process involving the methyl ester functional groups in pectin and lignin structural polymers of plant cells. Wide variations in baking styles allow only rough estimates of this flux of methyl halides on a global basis. A simple model suggests that CH3Br emissions from breadbaking likely peaked circa 1990 at approximately 200 tonnes per year (about 0.3% of industrial production), prior to restrictions on the dough conditioner potassium bromate. In contrast, CH3Cl emissions from breadbaking may be of similar magnitude as acknowledged present-day CH3Cl industrial emissions. Because the mechanisms involve functional groups and compounds widely found in plant materials, this type of methyl halide production may occur in other cooking techniques as well.
Place, publisher, year, edition, pages
2016. Vol. 551, 327-333 p.
Breadbaking, Methyl chloride, Methyl bromide, Chloromethane, Ozone, Potassium bromate
Earth and Related Environmental Sciences
IdentifiersURN: urn:nbn:se:su:diva-129892DOI: 10.1016/j.scitotenv.2016.01.213ISI: 000372589800035PubMedID: 26878644OAI: oai:DiVA.org:su-129892DiVA: diva2:926414