Atmospheric chemistry of N-nitroso dimethylamine

Abstract

Gaseous dimethylamine, (CH3)2NH, reacts in air with gaseous nitrous acid, HONO, to yield N-nitroso dimethylamine, (CH.LNNO. Long path infrared spectroscopy is used to monitor these reactions at concentration levels of partsper-million. The measured reaction rate shows that a small degree of nitrosation of dimethylamine vapor might take place during the night in a heavily polluted urban atmosphere. Nitrosation reactions would essentially cease after sunrise because the nitrous acid would be destroyed by photolysis. The N-nitroso dimethylamine vapor is also destroyed by sunlight, the half-life under full sun being about 30 min. By midday any nighttime accumulation of nitrosamine would be rather fully destroyed. Any N-nitroso dimethylamine detected in the air in the afternoon could not be the result of the reaction of precursors. It could only be the result of direct emissions of the pollutant.

Concentrations of the Carcinogen 4-(Methylnitrosamino)-1-(3-Pyridyl)-1-Butanone in Sidestream Cigarette Smoke Increase after Release into Indoor Air: Results from Unpublished Tobacco Industry Research

“…Most research has focused on nitrosation reactions in solution, but gas phase nitrosation has been reported in simulated outdoor atmospheres (41,42) and in an industrial environment in East Germany (43). It is known that the concentration of NNK in sidestream cigarette smoke is higher than that in mainstream cigarette smoke (7,44).…”

N-Nitrosodimethylamine (NDMA) as a Drinking Water Contaminant: A Review

“…Combustion often results in the formation of nitrogen-containing species (i.e., NO x or nitroso radicals) that react with species such as dimethylamine to produce nitrosamines. Relatively slow NDMA formation may occur in the atmosphere due to reaction of NO x (principally atmospheric nitrous acid) with dimethylamine released by industrial sources (Hanst et al, 1977;Cohen and Bachman, 1978). However, atmospheric NDMA may accumulate only at night because it degrades quickly by sunlight photolysis (Hanst et al, 1977;Tuazon et al, 1984).…”

“…On the basis of those observations, some researchers suggested that NDMA formed in the polluted atmosphere could be responsible for elevated urban cancer rates (Shapley, 1976). However, it was subsequently determined that a factory using dimethylamine was located near Belle, WV, and that air concentrations of NDMA in areas not impacted by industrial processes were orders of magnitude lower than the initial reports (Hanst et al, 1977;Cohen and Bachman, 1978;Fine, 1978).…”

Quantification of the unknown HONO daytime source and its relation to NO<sub>2</sub>

“…Besides its importance for the atmospheric oxidation potential, HONO is part of acid and nutrient deposition to the biosphere. Moreover, growing concern exists about possible health effects due to the formation of nitrosamines (Hanst et al, 1977;Pitts et al, 1978) where HONO acts as the nitrosating agent, especially in indoor environments after wall reactions of HONO with nicotine (Sleiman et al, 2010). Despite three decades of research since the first unequivocal detection of HONO in the atmosphere (Perner and Platt, 1979), HONO formation processes in the atmosphere are still under discussion, especially during daytime where large discrepancies were found between mixing ratios calculated from known gas phase chemistry and measured daytime mixing ratios .…”