Toxicology of Ngirimbo Samples across Chitipa District

Abstract Introduction: Smokeless tobacco describes a wide variety of tobacco products that do not require combustion, and is typically used either orally or nasally. Ngirimbo is a form of oral smokeless tobacco used by smokers in Malawi for tobacco harm reduction. The aim of this study was to determine the acidity (pH), nicotine content, mineral content (iron, zinc, calcium, magnesium and copper), heavy metal content (lead, chromium and cadmium), and presence of other volatile compounds in ngirimbo across Chitipa District in Malawi . Methods: Atomic absorption spectrophotometry and gas chromatography-mass spectrometry were used to estimate nicotine content, concentration of toxic heavy metals, minerals of potential toxicity and other harmful chemicals in the samples. Results: Samples were found to contain harmful chemicals, high pH and nicotine [2-(1-methyl-2-pyrolidinyl)-pyridine, (S)- and (S)-3-(1-methyl-2-pyrolidinyl)-pyridine] levels. Mineral concentrations were found to be much higher than typical safety limits. Conversely, samples were not found to contain lead, and had low concentrations of chromium and cadmium. Conclusions: These findings suggest that prolonged use of ngirimbo is a significant health risk to people with chronic diseases. Nonetheless, ngirimbo provides a valid method of tobacco harm reduction and a potential smoking cessation tool. Therefore, further analytical toxicological studies are needed to fully characterize variations in the quality of the product. Implications : Consumers of ngirimbo are susceptible to acute toxic effects of oral and dermal exposure to the product, as well as addiction. Some individuals would suffer from convulsions or seizures following ngirimbo use, and other clinical consequences depending on the amount ingested. However, understanding the amount of nicotine, and other volatile constituents, consumed through ngirimbo use will help to generate recommendations for quantity and frequency of use. Further, establishing the threshold of harm for nicotine consumption will contribute to the extraction, isolation, and use of nicotine as a smoking-cessation agent, and for treating psychiatric disorders such as schizophrenia and neurodegenerative diseases such as Alzheimer’s.