However, there have been conflicting claims about the degree to which these products warrant a health concern. In a literary study of e-cigarette health risks, 388 different symptoms were reported; mouth and throat concerns generated more negative symptoms than any other group. There are not enough studies or sufficient evidence to suggest that products, particularly the contaminants of the aerosol in e-cigarettes, produce health risks at a concerning level. More research is currently being conducted to find the true dangers of the use of humectants in cigarettes.