Assessment of the validity of self-reported smoking status among schoolchildren in Sousse, Tunisia

Introduction: Tobacco use, which begins in adolescence and childhood and continues in later life, is the major avoidable risk for non-communicable diseases and death in the world. Self-reports have frequently been used to estimate smoking prevalence and health consequences. This study explores the validity of self-reports of smoking behavior among schoolchildren in Tunisia. Materials and methods: This study was conducted in March 2014 among a sample of 147 schoolchildren randomly selected. Data concerning the smoking habit were collected by a questionnaire designed for the purposes of this work. Then, exhaled CO, a biochemical marker of smoke exposure, was measured using piCO+ Smokerlyzer® breath CO monitor among participants. Sensitivity and specificity of self-reports were calculated. Results: The prevalence of reported smoking was 9.5% with 16.7% and 1.7% respectively among boys and girls. Their mean age was 14.5±1.28 years old. When considering 4 ppm as the cut-off level of breath CO, sensitivity and specificity of self-reports were 100% and 93.7%, respectively. But at a breath CO cut-off of 3 ppm, self-reporting was 62.5% sensitive and 93.5% specific. Conclusion: According to our findings, we suggest that self-reports can be considered as a good tool to be used with a reasonable confidence to assess the smoking status

Stable and effective eco-enzyme cocktails in powder and liquid form of Stachybotrys microspora used as detergent additives

Objective: The present work aims to optimize fermentation parameters for the simultaneous production of eco-enzymes: proteases, amylases, and endoglucanases from the same fungus Stachybotrys microspora, and to evaluate their stability in free form and formulated in lye as detergent additives. Methods: Initially, enzyme cocktail production was assayed in a medium comprising inexpensive waste biomass. Using the best substrate, we investigated the effect of its different concentrations and the NaCl concentration on the three enzymes co-production. Next, we studied the effect of several additives on the storage stability of the lyophilized enzyme cocktail (powder in liquid forms) free and incorporated in commercial laundry detergent. Finally, the washing efficiency analysis of the newly formulated enzyme cocktail was evaluated on dirty tissue pieces with different stains. Results: The highest enzymatic cocktail production was achieved at 30 °C for 96 h after adding 0.1% NaCl and 1.5% wheat bran as waste biomass in the basal culture medium. The effect of adding maltodextrin, sucrose, or polyethylene glycol 4000 during freeze-drying showed that maltodextrin is the best additive to protect the activities of proteases, amylases, and cellulases of liquid and powder enzyme form. Additionally, the liquid formulation of these enzymes showed excellent stability and compatibility with 1% maltodextrin and 10% glycerol. Interestingly, we have developed a new formulation of an enzyme cocktail (liquid and powder) stable and highly compatible with detergents. Comparing the washing performance of different formulations containing our enzyme cocktail to commercial ones showed significantly better removal of different types of stains. Conclusions: This research shows a cost-effective approach to simultaneously produce proteases, amylases, and endoglucanases from Stachybotrys microspora that could be considered a compatible detergent additive in the green detergent industry