Toxicological assessment of kretek cigarettes part 4: Mechanistic investigations, smoke chemistry and in vitro toxicity

Prevalence and risk factors of oral potentially malignant disorders in Indonesia: a cross-sectional study undertaken in 5 provinces

Detection of subjects with oral potentially malignant disorders in a population is key to early detection of oral cancer (OC) with consequent reduction of cancer-related morbidity and mortality. Our aim was to investigate the prevalence and associated risk factors for OPMD in representative provinces of Indonesia. This cross-sectional study was undertaken in five Indonesian provinces: West Java (WJ), Jakarta (JKT), West Papua (WP), West Kalimantan (WK) and Banda Aceh (BA). Respondents answered a previously validated questionnaire including information on ethnicity, occupation, socioeconomic status (SES), oral health practices, and behaviours associated with oral cancer. An oral examination was undertaken using WHO standardized methodology. Data were analysed using ANOVA, Chi-Square, and logistic regression to assess association between risk factors and mucosal disease. A total of 973 respondents between the ages of 17 and 82 years was enrolled (WJ 35.5%,JKT 13.3% WP 18.3%, WK 9%, BA 23.9%). Tobacco smoking (14.8%), Betel quid (BQ) chewing (12.6%) and alcohol drinking (4%) varied geographically. A well-established OPMD was detected in 137 (14.1%) respondents and 2 (0.2%) presented with chronic ulceration later diagnosed as OC. Leukoplakia was the most common OPMD found (9.7%), while the prevalence of oral submucous fibrosis (OSMF), not previously described in the nation, was 2.3%. Poor knowledge of OC risk factors, poor oral hygiene behaviours, low-income SES and ethnicity were significantly associated with the presence of an OPMD. There is a previously under-reported high prevalence of OPMD in Indonesia. Overall, we found a strong correlation between the presence of an OPMD and individual habituation to known risk factors.

Where should I start? A scoping review about the publications on clove cigarettes

INTRODUCTION

The general lack of knowledge about the composition of clove cigarettes and the large number of terms that can be used to define different types of cigarettes that contain cloves makes it difficult to find scientific articles focused on the subject. We reviewed the publications that cited clove cigarettes to assess their relevance.

METHODS

We searched publications on Scopus, ScienceDirect, PubMed, and Portal CAPES during the first semester of 2021, without date restrictions. Through a quality assessment, the studies found were assorted in ten different categories.

RESULTS

Indonesian clove cigarettes-also known as kretek-are a mixture of tobacco and cloves rolled in a cigarette and sprayed with oils, plant extract, and food flavorings, in an unknown quantity and composition, different from each brand, which is usually kept in secret. Due to the relatively low prevalence of use in the general population, most publications on tobacco products tend to ignore clove cigarettes or place them in an existing category. Clove cigarettes can be hand-rolled, machine-made, filtered, unfiltered, and each form can be named differently. The interchangeable use of each term, sometimes grouping conventional cigarettes in the mix, can lead the researcher to consider a publication that should be excluded.

CONCLUSION

The existing regulations on flavored cigarettes, although well-intentioned, are still somewhat vague and broad, leaving possible loopholes that can be exploited by the tobacco industries. Fully understanding the precise effects caused by clove cigarettes can be an important tool in future discussions about tobacco control.

Toxicological assessment of kretek cigarettes: Part 2: kretek and American-blended cigarettes, smoke chemistry and in vitro toxicity

Two commercial kretek cigarettes typical for the Indonesian market and a reference kretek cigarette were compared to the American-blended reference cigarette 2R4F by smoke chemistry characterization and in vitro cytotoxicity and mutagenicity assessments. Despite the widely diverse designs and deliveries of the selected kretek cigarettes, their smoke composition and in vitro toxicity data present a consistent pattern when data were normalized to total particulate matter (TPM) deliveries. This confirms the applicability of the studies' conclusions to a wide range of kretek cigarette products. After normalization to TPM delivery, nicotine smoke yields of kretek cigarettes were 29-46% lower than that of the 2R4F. The yields of other nitrogenous compounds were also much lower, less than would be expected from the mere substitution of one third of the tobacco filler by clove material. Yields of light molecular weight pyrolytic compounds, notably aldehydes and hydrocarbons, were reduced, while yields of polycyclic aromatic hydrocarbons were unchanged and phenol yield was increased. The normalized in vitro toxicity was lowered accordingly, reflecting the yield reductions in gas-phase cytotoxic compounds and some particulate-phase mutagenic compounds. These results do not support a higher toxicity of the smoke of kretek cigarettes compared to American-blended cigarettes.

Toxicological assessment of kretek cigarettes Part 3: kretek and American-blended cigarettes, inhalation toxicity

A typical Indonesian kretek cigarette brand and an experimental kretek reference cigarette were compared to the reference cigarette 2R4F in two 90-day inhalation studies. Male and female rats were exposed nose-only to mainstream smoke for 6 hours daily, for 90 consecutive days. Biological endpoints were assessed according to OECD guideline 413, with special emphasis on respiratory tract histopathology and on lung inflammation (broncho-alveolar lavage fluid levels of neutrophils, macrophages and lymphocytes). Histopathological alterations included: in the nose, hyperplasia and squamous metaplasia of the respiratory epithelium and squamous metaplasia and atrophy of the olfactory epithelium; in the larynx, epithelial squamous metaplasia and hyperplasia; in the lungs, accumulation of macrophages in alveoli and goblet cell hyperplasia in bronchial epithelium. The findings were qualitatively consistent with observations from previous similar studies on conventional cigarettes. Compared to 2R4F cigarette, however, kretek smoke exposure was associated with a pronounced attenuation of pulmonary inflammation and less severe histopathological changes in the respiratory tract. Neutrophilic inflammation was also significantly lower (>70%). These results are consistent with the observations made on smoke chemistry and in vitro toxicology. They do not support any increased toxicity of the smoke of kretek cigarettes compared to conventional American-blended cigarettes.