Assessing Toxicity of Waterpipe Tobacco Smoking

Globally, 1 in 3 adults or 1.2 billion people smoke. The World Health Organization (WHO) estimated that tobacco is responsible for the death of 1 in 10 adults worldwide, about 6 million premature deaths each year. In the United States (U.S.), cigarette smoking is responsible for more than 480,000 deaths per year, including nearly 42,000 deaths resulting from secondhand smoke exposure. Tobacco use is the single leading most preventable cause of disease, disability, and mortality in the U.S. Tobacco research tends to focus on cigarettes; however, the rise in waterpipe (WP) tobacco use globally warrants studying all aspects of its toxicity. In 2005, the WHO called for a better understanding of WP tobacco smoking. In 2007, the American Lung Association labeled WP smoking as an emerging deadly trend. WP tobacco use was associated with increased risk for Chronic obstructive pulmonary disease (COPD), heart diseases, lung cancers, oral and esophageal cancers.

COPD is a major public health problem leading to airflow obstruction. In the U.S., tobacco smoke is a key factor in the development of COPD, which was the third leading cause of death in the U.S. in 2014. WP smoking decreases respiratory quality of life in adults. Studies found that pulmonary function following WP smoking was impaired as measured by forced expiratory volume (FEV1), forced vital capacity (FVC), FEV1/FVC, and Forced Expiratory Flow (FEF25-75%). Studies investigating acute cardiovascular injury markers due to WP smoking showed significant increases in heart rate, and in systolic and diastolic blood pressure.

In 2014, the U.S. Food and Drug Administration (FDA) initiated regulation WP tobacco. The FDA proposed that the manufacturers of WP tobacco disclose to the FDA their products' ingredients and report harmful and potentially harmful constituents (HPHCs). A review study showed that exposures to HPHCs are 10-100 times higher in WP tobacco smoke than in cigarette smoke. To inform the FDA on the regulation of WP tobacco products, and reduce the harm of it use, the investigators propose a Waterpipe Project in a natural setting to determine the differential effects of WP smoking practices on physiological injury markers, and biomarkers of toxicants and carcinogens.

Worldwide, the WP is used in Africa, Asia, China, India, and the Middle East. Adolescents and young adults in the U.S. are experimenting with WP smoking. The 2014 U.S. National College Health Assessment II found that nearly one third of U.S. undergraduate college students (38.2% of men and 31.4% of women), reported ever using WP tobacco, and 11.6% of men and 8.3% of women reported current use (past 30 days). Among high school students, the 2013 U.S. National Youth Tobacco Survey showed that 15.1% of boys and 13.5% of girls reported ever WP use.

The WP (hookah) consists of a head, a body, a hose, and a water jar. The tobacco is placed in the head and covered with a perforated aluminum foil to allow air-flow. Burning charcoal is placed on top of the aluminum foil. Upon deep inhalation via the WP hose, suction forces hot air through the head, heating and combusting the tobacco to produce the smoke that is forced down the WP body, into and out of the water in the airtight jar, and through the hose into the smoker's mouth and respiratory system. Smokers inhale charcoal toxicant emissions in addition to those from the WP tobacco. Charcoal combustion contributes greatly to benzene, carbon monoxide (CO) and carcinogenic yields. CO is a smoke toxicant that reduces the blood's ability to transport oxygen to various organs, including the brain, and can cause dizziness, headache, syncope and nausea.

A charcoal-free electrically heated WP head is commercially available. Users were satisfied with this device because they did not have to deal with charcoal fire hazardous ambers and ashes, in addition to enjoying the feeling of reduced harm. WP smokers normally use room temperature water in the WP jar. However, other liquid media are gaining in popularity. According to anecdotal evidence, "adding ice cubes in the WP jar has an enjoyable cooling effect to the inhaled smoke". Smokers practice adding ice cubes at home, and for an extra charge hookah lounges provide this option for customers. Toxic chemicals in WP tobacco smoke include cotinine, a metabolite of the addictive drug nicotine; 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) and NNAL-glucuronides (total NNAL); metabolites of the lung carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK); 1-hydroxypyrene (1-HOP), a metabolite of the genotoxic carcinogen pyrene; and S-phenylmercapturic acid (SPMA), a metabolite of the human hematotoxicant and leukemogen benzene; and Furan-BDA-NAL, a metabolite of the carcinogen furan.

METHODS. will compare exhaled CO, pulmonary functions, blood pressure, heart rate and respiratory rate, and urinary levels of cotinine, NNAL, SPMA, and 1-HOP in first void WP smoker urine samples the morning of, and the morning after a WP smoking session across 3 smoking practices. The investigators will recruit a sample of 50 adult male and female exclusive WP smokers and a control sample of 25 male and female non-smokers. Participants will be recruited and qualified via random intercept screen interviews from San Diego County, California communities. Over a 3-week study period, WP smokers will smoke one WP tobacco head (10g) of Starbuzz during 3 separate sessions with a 7-day washout period before each session in their home in a natural setting: Week 1-Session 1, WP smokers will smoke using 1 quick-light charcoal and room temperature water in the WP jar, Week 2-Session 2, WP smokers will smoke using 1 quick-light charcoal but adding ice cubes to the water in the WP jar, Week 3-Session 3, WP smokers will smoke WP tobacco without charcoal using the electric WP head and room temperature water. The investigators will collect the following forms: a) Tobacco Use History; b) 3-week Tobacco Use and Exposure Diaries; c) WP Smoking Session Day and Exposure Form; and will measure d) CO exposure: Micro+ Smokerlyzer® CO monitor will be used for exhaled CO two minutes pre and post each smoking session; e) Pulmonary function testing and measuring blood pressure, heart rate and respiratory rate pre and post each smoking session; and f) 6 first morning urine samples: pre and post the 3 sessions to measure urinary cotinine, NNAL, 1-HOP, SPMA, and Furan-BDA-NAL. Efforts will be made to recruit equal samples of males and females. Flexible scheduling for study activities where applicable. Proration of incentives will apply for completed activities.

The 3-Week Study period: comprised of 3 WP smoking sessions with 7-day wash-out periods

WP Smoking Session 1. Day 1 - Office Visit: The Office Visit is expected to take between 60 and 90 minutes where potential participants will be trained on the study activities. Consent will be obtained, study forms will be completed, and study related materials such as forms and urine cups will be provided. Scheduling will be arranged for the 3 WP smoking sessions and corresponding home visits. Saliva Test: Trained by the PI, the RAs will use NicAlert, an accurate and valid commercial semi-quantitative instant saliva cotinine test, to validate non-smoking status, which the investigators used successfully in their previous studies. The following physiological baseline data will be collected: pulmonary functions, blood pressure, heart rate and respiratory rate. Days 2 - 6: The RAs will contact participants by phone on the 4th day to confirm adherence to the 7-wash-out period and diaries, and on the 6th day to remind participants to collect the first morning urine sample on day 7, and to arrange for a home visit for the first WP smoking session. Day 7: WP smoking session 1. WP smokers will provide one first morning urine sample and store it in their refrigerator (freezer section). WP smokers will smoke WP tobacco (10 grams) as they normally do using charcoal and room temperature water in the water jar. The RAs will collect expired CO levels 2 minutes before and 2 minutes after concluding smoking, and will measure pulmonary functions, blood pressure, heart rate and respiratory rate thereafter. Day 8: Participants will provide a first morning urine sample. The RAs will pick up the 2 urine samples (frozen in a cooler to transfer them to the research center laboratory), and arrange for the 2nd WP smoking session home visit, provide forms, urine cups package for week 2 of the study. WP Smoking Session 2. Days 1 through 7 are similar to session 1 with the exception that the RAs will add one tray of ice cubes and water in the WP jar. The RAs will arrange for a training session to use the charcoal-free electrically heated WP head. WP Smoking Session 3. Days 1 through 7 are similar to session 1 using room temperature water in the WP jar, however using the charcoal-free electrically heated WP head instead of using charcoal. During the last visit, the day after the 3rd smoking session, the RAs will interview participants to complete the Illnesses and Health Care History Form, pick up the final urine samples, and thank the participants.