Yehya Elsayed

Midwakh, which originated in the Middle East, has started to spread globally with different brands commercialized online and in local stores across Europe and the USA. Dokha is the tobacco used in midwakh. To this day, risk of midwakh smoking is poorly understood. Three different types of dokha were evaluated in this study, classified as cold, medium, and hot using gas chromatography–mass spectrometry (GC–MS). The concentrations of nicotine and polycyclic aromatic hydrocarbons (PAHs) in raw and smoked dokha samples were measured, and the results were compared to data in the literature on different types of tobacco products. PAH concentrations were used to estimate the toxic equivalency quotient, daily exposures, incremental lifetime cancer risk, and hazard quotient. The level of nicotine in raw dokha exceeded by far the levels reported in cigarettes, cigar, waterpipe, and chewing tobacco. Although only a portion of the nicotine is released into the smoke, the amount of nicotine in dokha smoke exceeded those reported for cigarettes. Two PAHs were found in raw dokha at trace amounts and 12 PAHs were detected in dokha smoke in amounts that exceeded those reported for cigarette smoke. The PAHs distribution showed a specific pattern in the smoke and a higher risk factor than that obtained for cigarettes and other tobacco products. Dokha products present a potential higher risk and immediate action should be taken to avoid its global consumption.

Non-cigarette tobacco products are an increasing public health concern globally. Little is known about midwakh, a pipe indigenous to the United Arab Emirates (UAE). This study aimed to assess the prevalence, attitudes, behaviours and policy evaluation of midwakh smoking among 13 to 15 year olds in the UAE. We conducted secondary analyses of the 2013 UAE Global Youth Tobacco Survey. The main three outcomes were ever use, current use (past-30 days), and the number of midwakhs smoked per day. We assessed cessation, attitude, and policy measures. Regression models identified the association between each outcome measure and sex, school grade, nationality, weekly spending money, cigarette use, and parent and peer tobacco use. The prevalence of ever and current midwakh use were 18.5% and 9.0%, respectively. Daily midwakh users smoked a median of 8.0 per day while non-daily users smoked 3.8 per month. Higher midwakh prevalence was reported among wealthier males, older age groups, concurrent cigarette users and among participants having peers or parents who use tobacco. There was also variation by nationality. Reduced harm perception was greater among midwakh users than non-users. About 39.6% reported being declined a midwakh purchase due to age, and 35.5% reported noticing health warnings on packages. Midwakh use is prevalent among 13 to 15 year olds in the UAE, and burden lies mainly with daily users. Further needed research should not delay implementation and evaluation of policies known to curb tobacco use among youth, including taxation, media campaigns, and provision of cessation services.

Desulfurization of diesel fuel was performed using two commercial activated charcoal sorbents. The two activated charcoals used in this study (PAC1 and PAC2) were powders. The desulfurization for diesel fuel was done at room temperature using 10 % by mass of the adsorbents with contact time of 1 hour. The surface chemistry and structure of the sorbent materials were studied using surface area analyzer and scanning electron microscopy (SEM) integrated with energy dispersive spectroscopy (EDS). The desulfurization process was evaluated using X-ray fluorescence analyzer. The activated charcoal samples showed to reduce the sulfur content down to 66.2% of the original sulfur content (398 ppm). The metal content of the sorbent materials, before and after desulfurization process, was determined using inductively coupled plasma (ICP) technique. Prior to analysis, the samples were prepared using microwave acid digestion. The desulfurization process resulted in a lower metal content in the fuel. The effect of the desulfurization process on the ignition quality, physical and chemical properties of the diesel fuel was studied. The amount of carbon residue, diesel index, calculated cetane index, and carbon aromaticity were evaluated. The ignition quality of the diesel fuel was improved by the adsorption desulfurization.