BMI and Medically Certified Long-Term Sickness Absence Among Japanese Employees

OBJECTIVE

In contrast to the association between excess weight and sickness absence (SA), the association in relation to underweight has been under-researched. This study aimed to examine the effects of BMI at both extremes of its distribution on SA.

METHODS

Data came from the Japan Epidemiology Collaboration on Occupational Health study of 77,760 workers aged 20 to 59 years (66,166 males, 11,594 females). Information was collected on medically certified long-term SA (LTSA) (i.e., SA lasting ≥ 30 consecutive days) from April 2012 to March 2017. A sex-specific Cox proportional hazards model was used to investigate the associations.

RESULTS

Among males, both obesity (hazard ratio [HR] = 1.81, 95% CI: 1.50-2.17) and underweight (HR = 1.56, 95% CI: 1.23-1.96) were significantly associated with LTSA compared with normal weight. This U-shaped association between BMI categories and LTSA was observed both for mental and physical disorders. Among females, an elevated risk was observed among those with overweight (HR = 1.54, 95% CI: 1.16-2.05).

CONCLUSIONS

In a cohort of the Japanese working-age population, both obesity and underweight were associated with a greater risk of LTSA in males. Future research should not overlook the excess risk of LTSA associated with underweight.

[Policy recommendation for the regulation of heated tobacco products based on evidence review of their health effects and influence on tobacco control]

Objective This report aimed to present policy recommendations on the regulation of heated tobacco products based on a review of the literature on the use of heated tobacco products, component analysis of harmful chemical substances, and product characteristics as nicotine delivery device, and on an examination of the influence of the product's increasing usage to the main measures of tobacco control.Methods The literature search was performed using Japan Centra Revuo Medicina and PubMED database. The search yielded 11 articles that examined the use of heated tobacco products, component analysis of harmful chemical substances, and product characteristics as nicotine delivery device. Eight articles were additionally collected from reports of public health research in Japan and public reports in foreign countries. The six main policies advocated by World Health Organization as MPOWER (Monitor, Protect, Offer, Warn, Enforce, Raise) were adopted in considering the expected influence of this product's increasing usage this product epidemic on tobacco control. In addition to the abovementioned 19 articles, 26 documents and materials related to the status of tobacco control were collected and used to examine the influence of the product's increasing usage to the main measures of tobacco control.Results In Japan, heated tobacco products have been available since December 2013, and the spread of use has risen remarkably since 2016. As of October 2016, Japan consumed more than 90% of the heated tobacco products sold internationally. Compared with cigarettes, heated tobacco products can reduce exposure to harmful substances except nicotine. However, their use does not lead to reduced risk of illness. The reduction of exposure to harmful substances cannot be expected when used in combination with cigarettes. Heated tobacco products and cigarettes have similar nicotine exposure levels and pharmacokinetics; thus, use of the former results in nicotine dependence and exacerbates the difficulty in discontinuing tobacco consumption. The popularity of heated tobacco products could adversely affect any of the six main measures of tobacco control.Conclusion Although public health concerns have been identified for the popularity of heated tobacco products, evidence remains insubstantial for the formulation of regulatory implications. Additional research is needed on the health effects to users and bystanders, effects on cigarettes use, and influence on tobacco control policy. From the perspective of the precautionary principle of public health, the same regulation as for cigarettes should be implemented as regards heated tobacco products until their health effects are fully elucidated.

Five-year cumulative incidence of overweight and obesity, and longitudinal change in body mass index in Japanese workers: The Japan Epidemiology Collaboration on Occupational Health Study

OBJECTIVE

The present study aimed to estimate cumulative incidence of overweight and obesity and describe 5-year longitudinal changes in body mass index (BMI) in a large occupational cohort in Japan.

METHODS

Participants were 55 229 Japanese employees, who were aged 20-59 years and attended at all subsequent annual health check-ups between 2009 and 2014. Mixed model analysis was performed to examine the effects of age and cohort by gender on BMI change, with age as a random variable. Cumulative incidence of overweight (23.0≤ BMI <27.5 kg/m2 ) and obesity (BMI ≥27.5 kg/m2 ) was calculated. Logistic regression analysis was used to estimate odds ratios for the incidence of overweight and obesity according to age group.

RESULTS

The incidence of overweight and obesity was approximately double in men (28.3% and 6.7%, respectively) compared to women (14.3% and 3.9%, respectively).The incidence of obesity decreased with age in men, but did not differ according to age in women (P for trend: .02 and .89, respectively). Among overweight participants, the incidence of obesity was higher in women (18.9%) than men (14.5%) and decreased with advancing age (P for trend: <.001 in men and .003 in women). Mean BMI was higher in men than women in all age groups throughout the period. Younger cohorts tended to have a higher BMI change compared with older cohorts.

CONCLUSIONS

In this Japanese occupational cohort, transition from overweight to obesity is higher in women than men, and the more recent cohorts had a higher change in mean BMI than the older cohorts.

A novel analytical method for simple and low-cost detection of isocyanates in ambient air

In this study, we developed a novel method for the collection of gaseous and particulate isocyanates in the air using di-n-butylamine (DBA)-coated glass fiber filters and a cation-exchange column (GFF_SCX-DBA) sampler. Our method showed acceptable linearity, accuracy, and precision in the analysis of eleven kinds of isocyanates (ICA, MIC, EIC, PIC, PHI, 1,6-HDI, 2,4-TDI, 2,6-TDI, trans-IPDI, cis-IPDI, and 4,4'-MDI). And, some of them were detected in the air at the plant manufacturing isocyanates and spray polyurethane foam. Actually, 2,4-TDI and 2,6-TDI (11,000 ± 6600 and 5800 ± 3500 ng/m³, respectively) were detected at much higher levels than others at the plant manufacturing isocyanates, and the levels of these isocyanates were comparable with those obtained by using the commercial sampler. Furthermore, PHI and 4,4'-MDI (5800 ± 470 and 3500 ± 1100 ng/m³, respectively) were detected at a relatively higher concentration than the others in the place of spray polyurethane foam. Through this study, we realized that the concentration of isocyanates in various working places could be analyzed using our GFF_SCX-DBA sampler. This method makes it possible to perform a rapid and simplified extraction operation in a shorter time than in the commercial sampler by combining the GFF and SCX samplers.

Association between anthropometric indices of obesity and risk of cardiovascular disease in Japanese men

Objectives

We aimed to compare the association of body mass index (BMI), waist circumference (WC), and waist‐to‐height ratio (WHtR) with risk of cardiovascular disease (CVD) among middle‐aged working Japanese men.

Methods

A nested case‐control study was performed among middle‐aged male employees who underwent periodic health checkup. A total of 241 CVD cases were identified and matched individually on age, gender, and worksite with 1205 controls. Data on BMI, WC, WHtR, smoking, hypertension, diabetes, and dyslipidemia collected at 4 years before the event/index date were retrieved. Associations between BMI, WC, WHtR, and CVD risk were assessed by using conditional logistic regression models.

Results

The strength of the association of BMI, WC, and WHtR with CVD risk was similar. The smoking‐adjusted odds ratio (95% confidence interval) for CVD was 1.60 (1.38‐1.85), 1.53 (1.33‐1.78), and 1.56 (1.35‐1.81) for a 1 SD unit increase in BMI, WC, and WHtR respectively. After further adjustment for hypertension, diabetes, and dyslipidemia, these associations were attenuated but remained statistically significant.

Conclusions

Measures of general (BMI) and abdominal (WC and WHtR) obesity were similarly associated with CVD in middle‐aged Japanese men.

Global Analysis of Transcriptional Expression in Mice Exposed to Intermediate Frequency Magnetic Fields Utilized for Wireless Power Transfer Systems

BACKGROUND

Intermediate frequency magnetic fields (IF-MFs) at around 85 kHz are a component of wireless power transfer systems used for charging electrical vehicles. However, limited data exist on the potential health effects of IF-MFs. We performed a comprehensive analysis of transcriptional expression in mice after IF-MF exposure.

MATERIALS AND METHODS

We developed an IF-MF exposure system to generate a high magnetic flux density (25.3 mT). The system can expose the IF-MF for a mouse whole-body without considering thermal effects. After 10 days (1 h/day) of exposure, a comprehensive expression analysis was performed using microarray data from both the brain and liver.

RESULTS

No significant differences in transcriptional expression were detected in the 35,240 probe-sets when controlling the false discovery rate (FDR) under a fold change cutoff >1.5. However, several differential expressions were detected without FDR-adjustment, but these were not confirmed by RT-PCR analysis.

CONCLUSIONS

To our knowledge, this is the first in vivo study to evaluate the biological effects of IF-MF exposure with an intense magnetic flux density 253 times higher than the occupational restriction level defined by the International Commission on Non-Ionizing Radiation Protection guidelines. However, our findings indicate that transcriptional responses in the living body are not affected under these conditions.

Epicatechin as a promising agent to countermeasure radiation exposure by mitigating mitochondrial damage in human fibroblasts and mouse hematopoietic cells

Accidental radiation exposure that is due to a nuclear accident or terrorism using radioactive materials has severe detrimental effects on human health, and it can manifest as acute radiation syndrome depending on the dose and distribution of the radiation. Therefore, the development of radiation countermeasure agents is urgently needed to protect humans against radiation injury. Besides nuclear DNA, the mitochondria are important targets of ionizing radiation (IR) because these organelles generate reactive oxygen species (ROS). Recently, we revealed that mitochondrial ROS-activated cell signaling is associated with IR-induced tumor formation. Here, we investigated the effectiveness of ascorbic acid and epicatechin (EC) in scavenging ROS as radiation countermeasure agents by using human cells and mouse. Preradiation and postradiation treatments with EC mitigate ROS-mediated mitochondrial damage, IR-induced oxidative stress responses including reduction of superoxide dismutase activity, and elevated nuclear factor erythroid 2-related factor 2 expression, and they improve human fibroblast survival. As well as in vitro, EC mitigated ROS-mediated mitochondrial damage after exposure to IR in vivo in mouse platelets. Furthermore, oral administration of EC significantly enhanced the recovery of mouse hematopoietic cells from radiation injury in vivo. In summary, EC is a potentially viable countermeasure agent that is immediately effective against accidental IR exposure by targeting mitochondria-mediated oxidative stress.-Shimura, T., Koyama, M., Aono, D., Kunugita, N. Epicatechin as a promising agent to countermeasure radiation exposure by mitigating mitochondrial damage in human fibroblasts and mouse hematopoietic cells.

Factors affecting self-reported chemical intolerance: A five-year follow-up study in Japan

OBJECTIVE

Chemical intolerance (CI) has become a strong public health concern in industrialized countries. The Japanese Chemical Intolerance (JCI) study was conducted in January 2012 with a cohort of 7245 adults from population-based sampling as the baseline. The aim of the present study was to investigate the factors involved in the improvement and development of CI from the five-year follow-up study.

METHODS

From the 7245 cohort, 735 persons with CI (case) were identified, and 1750 controls without CI were randomly selected to match gender and age for case and control groups. Self-reported questionnaires were administered to the subjects of the two groups to obtain information on status of CI; medical history; medical, lifestyle, or physical interventions; changes in living situation or occupation; and psychosomatic states.

RESULTS

A total of 909 individuals responded during the follow-up period. After five years, improvement in CI was observed in 67.7% of the case group. Status of CI was reported in 6.7% of the control group. Multiple logistic regression analyses revealed that baseline atopic dermatitis and negative psychosomatic states including irritability, fatigue, anxiety, depressed mood, and somatic symptoms were significantly associated with development of CI in controls. Appropriate physical activity and maintaining a regular lifestyle including diet or sleep during the last three years of the follow-up period were significant factors for improvement of CI in the case group.

CONCLUSIONS

Ensuring appropriate physical activity and regular lifestyle rather than improving physical environment lead to improvement of CI. Stable psychosomatic state is essential for preventing CI.

Changes in oxidative stress levels during two weeks of smoking cessation treatment and their association with nutritional characteristics in Japanese smokers

Although several experimental studies have reported that oxidative stress levels decrease during smoking cessation, how they change among general smokers has yet to be completely elucidated. In the present study, a total of 23 smokers who underwent smoking cessation treatment were observed for two-week changes in their levels of 8-OHdG and 8-isoprostane. Physical and nutritional characteristics were measured at the initial patient visit, and casual urine samples were collected at the initial visit and at a follow-up visit two weeks later. Oxidative stress was measured by a high performance liquid chromatography electrochemical detector, and the two-week difference in the levels of oxidative stress was assessed according to demographic and nutrient factors. Neither the urinary level of 8-OHdG nor that of 8-isoprostane decreased, although the cotinine level was decreased at two weeks. A Two-way repeated ANOVA revealed a significant interaction for fat intake by time for the change in the 8-OHdG level (P=0.03) and significant interactions for α-tocopherol intake (P=0.03), iron intake, and carbohydrate intake (P=0.03), all of which were time-dependent for the change in the 8-isoprostane level. The 8-OHdG level decreased among smokers with a high fat intake and was increased with a low fat intake. The 8-isoprostane levels were decreased among smokers with a high carbohydrate intake and increased with a low carbohydrate intake, decreased with a low iron intake and increased with a high iron intake and decreased with a low α-tocopherol intake and increased with a high α-tocopherol intake. Although the present study failed to observe a decrease in oxidative stress levels during the two-week smoking cessation period, we hypothesize that the intake levels of specific nutrients when initiating smoking cessation treatment may predict any subsequent changes in the oxidative stress levels.

Diagnosing the double burden of malnutrition using estimated deviation values in low- and lower-middle-income countries

Objective

To examine the possibility of diagnosing the double burden of malnutrition using estimated deviation values in low- and lower-middle-income countries.

Methods

A modified version of the Japanese Diagnostic Tool was used. Data on 194 countries were analyzed, including data from the United Nations International Children’s Fund, World Health Organization and World Bank. After conducting a Box–Cox transformation, deviation values were calculated. The degree to which the values deviated relative to a deviation cutoff value of 50 was assessed. Focusing on countries with low- and middle-income economic levels, we examined the utility of this tool to show characteristic nutritional problems in each country.

Results

The deviation values had normal, distorted, bimodal, or trimodal distributions. In the lower-middle-income countries, almost all countries had values ranging from 40 to 60 for education and water environments (urban and rural), and the differences were minimal. However, different causes of noncommunicable disease-related deaths were considered, and the primary cause appeared to be related to lifestyle factors, particularly alcohol consumption and tobacco smoking. In comparison, the deviation values related to death among low-income countries also appeared to be related to differences in education and sanitation in urban and rural areas.

Conclusion

The study results can help to determine the status of nutritional inequalities and plan country-specific strategies to reduce the double burden of malnutrition.

Study Profile: The Japan "Society and New Tobacco" Internet Survey (JASTIS): A Longitudinal Internet Cohort Study of Heat-Not-Burn Tobacco Products, Electronic Cigarettes, and Conventional Tobacco Products in Japan

Background

Japan became the first country where heat-not-burn tobacco products were sold. Therefore, there was no information for actual status on the actual use status or the harms of heat-not-burn tobacco products. The objectives of the study profile are to generate data that can be freely available to external researchers, and to create collaborative research projects in the future.

Methods

The Japan “Society and New Tobacco” Internet Survey (JASTIS) is a longitudinal internet cohort study which investigates perception, attitude, and use of heat-not-burn tobacco, electronic cigarettes (e-cigarettes), and conventional tobacco products in Japan. The survey also includes demographic, health-related, and socioeconomic factors. Participants were randomly selected and invited from internet panelists. The baseline survey was closed when the target number of respondents who had answered the questionnaire was met.

Results

The study includes three cohorts (1–3) from the 2015 baseline survey and a cohort (4) from the 2017 baseline survey: cohorts 1 and 4 were recruited based on sex and age: men and women aged 15–69 years (n = 8,240 for cohort 1 and n = 5,897 for cohort 4); cohorts 2 and 3 were created using status-based recruiting: e-cigarette and/or heat-not-burn tobacco ever users (n = 2,188; cohort 2) and combustible cigarette smokers without e-cigarette/heat-not-burn tobacco experience (n = 724; cohort 3). The completion rates were 8.5% to 9.9%. All subjects were followed and assessed annually. Response rates for the follow-up survey were 65.5% in 2016, 55.3% in 2017, and 50.9% in 2018. Because Internet-based responders are not a representative sample of the general population of Japan, we conducted adjustment to account for “being an internet survey respondent” and reported tobacco product use in Japan. A recent JASTIS study reported that prevalence of IQOS current-use among Japanese adults had rapidly increased from 0.3% in 2015 to 3.6% in 2017.

Conclusion

The JASTIS study provides the first estimates for heat-not-burn tobacco use in the world and e-cigarette use in Japan. For information on collaboration, please contact the corresponding author.

Smoking, Smoking Cessation, and Risk of Mortality in a Japanese Working Population - Japan Epidemiology Collaboration on Occupational Health Study

BACKGROUND

The effect of smoking on mortality in working-age adults remains unclear. Accordingly, we compared the effects of cigarette smoking and smoking cessation on total and cause-specific mortality in a Japanese working population. Methods and Results: This study included 79,114 Japanese workers aged 20-85 years who participated in the Japan Epidemiology Collaboration on Occupational Health Study. Deaths and causes of death were identified from death certificates, sick leave documents, family confirmation, and other sources. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated via Cox proportional hazards regression. During a maximum 6-year follow-up, there were 252 deaths in total. Multivariable-adjusted HRs (95% CIs) for total mortality, cardiovascular disease (CVD) mortality, and tobacco-related cancer mortality were 1.49 (1.10-2.01), 1.79 (0.99-3.24), and 1.80 (1.02-3.19), respectively, in current vs. never smokers. Among current smokers, the risks of total, tobacco-related cancer, and CVD mortality increased with increasing cigarette consumption (P_trend<0.05 for all). Compared with never smokers, former smokers who quit <5 and ≥5 years before baseline had HRs (95% CIs) for total mortality of 1.80 (1.00-3.25) and 1.02 (0.57-1.82), respectively.

CONCLUSIONS

In this cohort of workers, cigarette smoking was associated with increased risk of death from all and specific causes (including CVD and tobacco-related cancer), although these risks diminished 5 years after smoking cessation.

Radiation-Induced Myofibroblasts Promote Tumor Growth via Mitochondrial ROS-Activated TGFβ Signaling

Fibroblasts are a key stromal cell in the tumor microenvironment (TME) and promote tumor growth via release of various growth factors. Stromal fibroblasts in cancer, called cancer-associated fibroblasts (CAF), are related to myofibroblasts, an activated form of fibroblast. While investigating the role of stroma fibroblasts on radiation-related carcinogenesis, it was observed following long-term fractionated radiation (FR) that the morphology of human diploid fibroblasts changed from smaller spindle shapes to larger flat shapes. These cells expressed smooth muscle actin (α-SMA) and platelet-derived growth factor receptors, markers of myofibroblasts and CAFs, respectively. Long-term FR induces progressive damage to the fibroblast nucleus and mitochondria via increases in mitochondrial reactive oxygen species (ROS) levels. Here, it is demonstrated that long-term FR-induced α-SMA-positive cells have decreased mitochondrial membrane potential and activated oxidative stress responses. Antioxidant N-acetyl cysteine suppressed radiation-induced mitochondrial damage and generation of myofibroblasts. These results indicate that mitochondrial ROS are associated with the acquisition of myofibroblasts after long-term FR. Mechanistically, mitochondrial ROS activated TGFβ signaling which in turn mediated the expression of α-SMA in radiation-induced myofibroblasts. Finally, in vivo tumor growth analysis in a human tumor xenograft model system revealed that long-term FR-induced myofibroblasts promote tumor growth by enhancing angiogenesis.Implications: Radiation affects malignant cancer cells directly and indirectly via molecular alterations in stromal fibroblasts such as activation of TGFβ and angiogenic signaling pathways. Mol Cancer Res; 16(11); 1676-86. ©2018 AACR.

Simple Determination of Gaseous and Particulate Compounds Generated from Heated Tobacco Products

As a new form of cigarettes, heated tobacco products (HTPs) have been rapidly distributed worldwide. In this study, an improved method for analyzing gaseous and particulate compounds generated from HTPs is described. Smoke is collected using a GF-CX572 sorbent cartridge with 300 mg of carbon molecular sieves, that is, Carboxen 572 (CX572), and a 9 mm glass-fiber filter (GF). After collection, the CX572 particles from the cartridge are transferred along with the GF and deposited into a vial containing two phases of carbon disulfide and methanol. The CX572 particles settle into the lower carbon disulfide phase, while nonpolar compounds are desorbed. After the sample is allowed to stand, the solution is slowly stirred. The two-phase mixture of carbon disulfide and methanol is combined into a homogeneous solution. Polar compounds are then desorbed, while the desorbed nonpolar compounds remain in solution. For the analysis of carbonyl compounds, an enriched 2,4-dinitrophenylhydrazine solution is added to a portion of the combined solution for derivatization and subsequent high-performance liquid chromatography analysis. For the analysis of volatile organic compounds and water, a portion of the combined solution is analyzed by gas chromatography-mass spectrometry or equipped with a thermal conductivity detector. By applying the proposed GF-CX572 one-cartridge method to the analysis of the mainstream smoke generated from HTPs and traditional cigarettes, several chemical compounds are detected, and the chemical composition of smoke is revealed. The GF-CX572 one-cartridge method can analyze gaseous and particulate chemical compounds from the HTP smoke by utilizing not only the entire puff volume but also one puff volume because the GF-CX-572 cartridge can be replaced with a new cartridge within 3 s. An overview of the chemicals generated from HTPs is obtained in detail by one-puff volume sampling. In addition, the generated chemical compounds strongly depend on the temperature of tobacco leaves in HTPs.

Heat-not-burn tobacco product use in Japan: its prevalence, predictors and perceived symptoms from exposure to secondhand heat-not-burn tobacco aerosol

OBJECTIVES

A heat-not-burn (HNB) tobacco product, IQOS, was first launched in Japan and Italy as test markets and is currently in commerce in 30 countries. Using two data sources, we examined interest in HNB tobacco (IQOS, Ploom and glo), its prevalence, predictors of its use and symptoms from exposure to secondhand HNB tobacco aerosol in Japan, where HNB tobacco has been sold since 2014.

METHODS

Population interest in HNB tobacco was explored using Google search query data. Prevalence of HNB tobacco current use (ie, use in the previous 30 days) was calculated using a longitudinal internet survey of 8240 individuals (15-69 years old in 2015) followed up to 2017. Rates of perceived symptoms from exposure to exhaled aerosol of others' HNB tobacco were also calculated.

RESULTS

The largest internet search volume for IQOS occurred in April 2016 in the week after a popular national entertainment TV show introduced IQOS. For Ploom and glo, search volumes have remained limited since their launch. Prevalence of IQOS users increased from 0.3% in January-February 2015 to 0.6% in January-February 2016 and up to 3.6% in January-February 2017, while estimated rates of use of other HNB tobacco products remained low in 2017. Respondents who had seen the TV programme in 2016 were more likely to have used IQOS than those who had not seen it (10.3% vs 2.7%). Among never-smokers who had been exposed to secondhand HNB tobacco aerosol, nearly half reported at least one acute symptom, although these symptoms were not serious.

CONCLUSIONS

A popular TV programme triggered IQOS diffusion in Japan. Extrapolating from survey results to the general population, around 3.1 million people currently use IQOS in Japan. Tobacco control organisations and governments should closely monitor HNB tobacco and consider how to regulate it.

Determination of Chemical Compounds Generated from Second-generation E-cigarettes Using a Sorbent Cartridge Followed by a Two-step Elution Method

We developed an analytical method for analyzing electronic cigarette (E-cigarette) smoke, and measured the carbonyl compounds and volatile organic compounds generated by 10 brands of second-generation E-cigarettes. A glass filter (Cambridge filter pad) for particulate matter and a solid sorbent tube packed with Carboxen-572 for gaseous compounds were used to collect E-cigarette smoke. These were then analyzed using a two-step elution method with carbon disulfide and methanol, followed by high-performance liquid chromatography (HPLC) and gas chromatography mass spectrometry (GC/MS). Formaldehyde (FA), acetaldehyde (AA), acetone (AC), acrolein (ACR), propanal (PA), acetol (AT), glyoxal (GO), and methyl glyoxal (MGO) were detected by HPLC in some E-cigarettes. Propylene glycol (PG), glycerol (GLY), and some esters were detected by GC/MS. GO and MGO exist mainly as particulate matter. AA, AC, ACR, PA, and AT exist mainly as gaseous compounds. FA exists as both particulate matter and gaseous compounds. These carbonyl compounds have carbon numbers C1 - C3. The main components of E-liquid are PG (C3) and GLY (C3). Therefore, the oxidation of liquids, such as PG and GLY in E-cigarettes upon incidental contact with the heating element in E-cigarette, is suggested as being a possible cause for carbonyl generation. When the puff number exceeds a critical point, carbonyl generation rapidly increases and then remains constant. The results of this study are now being used to determine the following E-cigarette smoking protocol: puff volume, 55 mL; puff duration, 2 s; and puff number, 30. E-cigarette analysis revealed very large variation in carbonyl concentration among not only different brands, but also different samples of the same product. Typical distributions of carbonyl concentration were not observed in any of the E-cigarettes tested, and the mean values greatly differed from median values.

Spectrophotometric determination of ammonia levels in tobacco fillers of and sidestream smoke from different cigarette brands in Japan

BACKGROUND

The ammonia contained in tobacco fillers and mainstream and sidestream cigarette smoke accelerates nicotine dependence in cigarette smokers. Ammonia has been included in the non-exhaustive priority list of 39 tobacco components and emissions of cigarette published by the World Health Organization (WHO) Study Group on Tobacco Product Regulation. The development of a simple ammonia detection method will contribute to the establishment of tobacco product regulation under tobacco control policies and allow surveys to be conducted, even by laboratories with small research budgets.

METHODS

We developed a simple colorimetric method based on the salicylate-chlorine reaction and absorption spectrometry with two reagents (sodium nitroprusside and sodium dichloroisocyanurate). To compare this method to conventional ion chromatography, we analyzed the ammonia levels in tobacco fillers extracted from 35 Japanese commercially marketed cigarette brands manufactured by four tobacco companies (Japan Tobacco (JT) Inc., British American Tobacco (BAT), Philip Morris Japan, and Natural American Spirit). We also analyzed the ammonia levels in the sidestream smoke from cigarettes of the brands that were found to contain high or low tobacco filler ammonia levels.

RESULTS

The ammonia levels in the reference cigarette (3R4F) measured by our method and ion chromatography were similar and comparable to previously reported levels. The ammonia levels in tobacco fillers extracted from 35 cigarette brands ranged from 0.25 to 1.58 mg/g. The mean ammonia level of JT cigarette brands was significantly higher (0.83 ± 0.28 mg/g) than that of Natural American Spirit cigarette brands (0.30 ± 0.08 mg/g) and lower than those in the other two cigarette brands (1.11 ± 0.19 mg/g for BAT and 1.24 ± 0.15 mg/g for Philip Morris) (p < 0.001 by Bonferroni test). The ammonia levels in the sidestream smoke of CABIN, Marlboro Black Menthol, American Spirit Light, and Seven Stars were 5.89 ± 0.28, 5.23 ± 0.12, 6.92 ± 0.56, and 4.14 ± 0.19 mg/cigarette, respectively. The ammonia levels were higher in sidestream smoke than in tobacco filler.

CONCLUSIONS

Our simple colorimetric could be used to analyze ammonia in tobacco fillers and sidestream smoke. There were significant differences between the ammonia levels of the 35 commercially marketed cigarette brands in Japan manufactured by four tobacco manufacturers. Over 90% of the ammonia in sidestream smoke was in gaseous phase.