Risk Factors for Lung Cancer in Non-smokers in Xuanwei County of China

Tobacco smoking and some types of occupational exposures have consistently been considered as important etiologic factors of lung cancer in industrial countries. At the First World Conference of Lung Cancer (Wyndwer, 1983), it was stressed that more attention should be paid to finding out the causes of lung cancer in non-smokers.In Xuanwei County, Yunnan Province, annual lung cancer death rate was 27.7 per 100,000 in males, among China's highest, and 25.3 per 100,000 in females, the China's highest. The female's lung cancer death rate in Xuanwei County was even much higher than that of the same period in USA white women (ECACM, 1979; Mulvihill, 1976). Marked district variation in cancer mortality exists within Xuanwei County. The county can be divided into high-, medium- and low-mortality areas. Over 90% of the population arc farmers. The local residents traditionally burned three major kinds of fuels: 'smoky' coal, 'smokeless' coal and 'wood', for heating and cooking. The three lung cancer high mortality areas, including 'Chengguan', 'Rongcheng' and 'Laibin' communes, mainly burned the 'smoky' coal from Laibin smoky-coal mine. The fuel was burned in a shallow, unventilated fire pit in the floor of the dwelling. Fuel burning in shallow unventilated pits has resulted in high indoor air pollution levels. The concentrations of airborne particles (pm 10) inside houses during smoky coal and wood combustion were very high. Indoor concentration of suspended particulates and dichloromethane extractable organics were 24.4mg/m3 and 17.6mg/m3 in burning of 'smoky' coal; 22.3mg/m3, 12.3mg/m3 for burning wood; and 1.8mg/m3, O.Smg/m-1 for burning of smokeless coals. Levels of individual polycyclic aromatic hydrocarbons, including benzo(a)pyrene, were generally highest during burning of smoky coal, intermediate in burning wood, and least in smokeless coal. Women did most household chores, which include starting fire and cooking. Less than 0.2% of females smoked tobacco. The population-based case-control study presented here is to evaluate the influence of factors on the occurrence of lung cancer in non-smoking women in Xuanwei County and to supplement the etiologic factors of lung cancer in Xuanwei County.

Sex disparity of lung cancer risk in non-smokers:a multicenter population-based prospective study based on China National Lung Cancer Screening Program

Background: Non-smokers account for a large proportion of lung cancer patients, especially in Asia, but the attention paid to them is limited compared with smokers. In non-smokers, males display a risk for lung cancer incidence distinct from the females-even after excluding the influence of smoking;but the knowledge regarding the factors causing the difference is sparse. Based on a large multicenter prospective cancer screening cohort in China, we aimed to elucidate the interpretable sex differences caused by known factors and provide clues for primary and secondary prevention.Methods: Risk factors including demographic characteristics, lifestyle factors, family history of cancer, and baseline comorbidity were obtained from 796,283 Chinese non-smoking participants by the baseline risk assessment completed in 2013 to 2018. Cox regression analysis was performed to assess the sex difference in the risk of lung cancer, and the hazard ratios (HRs) that were adjusted for different known factors were calculated and compared to determine the proportion of excess risk and to explain the existing risk factors.Results: With a median follow-up of 4.80 years, 3351 subjects who were diagnosed with lung cancer were selected in the analysis. The lung cancer risk of males was significantly higher than that of females;the HRs in all male non-smokers were 1.29 (95% confidence interval [CI]: 1.20-1.38) after adjusting for the age and 1.38 (95% CI: 1.28-1.50) after adjusting for all factors, which suggested that known factors could not explain the sex difference in the risk of lung cancer in non-smokers. Known factors were 7% (|1.29-1.38|/1.29) more harmful in women than in men. For adenocarcinoma, women showed excess risk higher than men, contrary to squamous cell carcinoma;after adjusting for all factors, 47% ([1.30-1.16]/[1.30-1]) and 4% ([7.02-6.75]/[7.02-1])) of the excess risk was explainable in adenocarcinoma and squamous cell carcinoma. The main causes of gender differences in lung cancer risk were lifestyle factors, baseline comorbidity, and family history.Conclusions: Significant gender differences in the risk of lung cancer were discovered in China non-smokers. Existing risk factors did not explain the excess lung cancer risk of all non-smoking men, and the internal causes for the excess risk still need to be explored;most known risk factors were more harmful to non-smoking women;further exploring the causes of the sex difference would help to improve the prevention and screening programs and protect the non-smoking males from lung cancers.

Experiences of Being Non-Smoking among Adolescents in a Smoking Context

Introduction: A study among Greenlandic 13-year-old showed that 68 percent for boys and 55 percent for girls, and at age 15, 46 percent of the boys and 32 percent of the girls were non-smokers. A literature review showed that the behaviour of parents and peers, attitudes and expectations were crucial factors for the smoking habits of adolescents. Young adults would more likely start smoking if their parents, older siblings and/or friends were smokers. Parental support has been proven to be a preventive factor against smoking, especially if the school and leisure centers get involved. Group pressure, directly or indirectly, is often described as the most important reason why adolescents start smoking. The purpose was to study why some adolescents choose to be smoke-free in a society where the norm is to smoke. Methods: Adolescents who were non-smokers were interviewed in focus groups. The material was analysed using content analysis. Results: The contents analysis of the text resulted in eleven categories. Based on these, four themes were developed. These themes covered areas on the reasons for being smoke-free;how the smoke-free adolescents generally felt about smokers from a society or environment perspective, and also specifically from an individual perspective, such as how smokers took up space and did not show any consideration. There was a feeling among non-smokers of not belonging and of ambivalence, as well as a perspective of the future for adolescents in Greenland and an uncertainty about what would be required for a smoke-free environment. Conclusions: In a context where the norm is to smoke, the adolescents need to make a conscious choice to be smoke-free, and there were different reasons for this choice. This choice means becoming an outsider in their group of peers as well as the overall social culture. Smokers were seen as taking up too much space, as their needs ruled and this was deemed inconsiderate.

Study the Relationship between the Nicotine and Lipid Profile with Some Hematology Parameters in Serum of Smoker and Non-Smoker Blood Samples

The effect of cigarette smoking on lipid profile and CBC (Complete Blood Count) of blood was investigated in this study. Spectrophotometric methods were used to estimate the amounts of nicotine, cholesterol, triglycerides, and HDL-cholesterol. The findings revealed that cigarette smokers and the duration of smoking had significantly higher levels of nicotine and cholesterol when compared to non-smokers. The data also revealed differences in the contents of hematological parameters between smokers’ and non-smokers’ blood samples, with high counts of WBC, MCHC, HGB, and PLT clearly visible in the smokers’ samples. However, there was no discernible effect on RBC, MCV, or MCH counts in the trial. Smoker samples had high PLT values (243.8 ± 84.26), while non-smoker samples had lower PLT values (229.3 ± 30.07 on average).

Impact of Local Application of Clindamycin in Preventing Dry Socket after Third Mandibular Molar Extraction

Extraction of third mandibular tooth is one of the most commonly performed surgical procedures in oral surgery. One of the most common complications following the extraction of third mandibular molar teeth is dry socket (alveolar osteitis). Dry socket is the delayed healing of the wound of the alveolar bone after dental extractions. The purpose of this study was to determine if the intra-alveolar application of Clindamycin could reduce the incidence of dry socket following the extraction of third mandibular molar tooth. Patients who qualified for the prospective, randomized, double-masked, placebo-controlled trial were randomly divided into 2 groups, each group 30 patients. The first group (30 patients) included smokers and the second group (30 patients) included non smokers. Both groups had the mandibular third molar extracted in both sides at the same time. In total, 120 third molars were extracted. The left site was a study group in which we applied the clindamycin and the right site was a control group. The patients were also divided by gender. Dry socket occurred in 3.3% of cases for patients whom were given Clindamycin, regardless of their smoking habits, as opposed to 31.7% for those who did not receive the antibiotic. Results clearly showed that Clindamycin had a huge impact on reducing dry socket regardless of smoking habits.

Effects of Meat Intake Frequency and Polymorphic Cytochrome P450 2A6 Activity on Individual Colorectal Tumour Risk in a Japanese Cohort

The relationships among meat consumption, smoking habits, and phenotypic cytochrome P450 2A6 variation with respect to colorectal cancer risk remain unclear. In this study, the relationships among colorectal tumour risk, meat consumption by questionnaire, and phenotypic P450 2A6 activity by genotyping in a case-control study (299 cases and 170 controls) were analyzed for never-smokers and ever-smokers. In never-smokers consuming ≥1 serving per day of total meat, a significant odds ratio of 4.42 (95% confidence interval, 1.29 - 15.2), adjusted by logistic regression for age and gender, was observed, compared with the group consuming ≤2 servings per week. Furthermore, in Japanese never-smokers, the susceptibility to colorectal tumours was dependent on the frequency of meat intake (trend test p = 0.011). In never-smokers who were P450 2A6 poor metabolizers and had a high frequency of meat intake, the apparent odds ratio was 3.57 (95% confidence interval, 0.30 - 42.2) compared with the P450 2A6 normal group with a low meat intake frequency. These results suggested that colorectal tumour risk was inversely associated with the phenotypic P450 2A6 activities in Japanese never-smokers with a high meat intake.

New Silver Nanosensor for Nickel Traces. Part II： Urinary Nickel Determination Associated to Smoking Addiction

A new fluorescence silver nanosensor assisted by surfactant has been recently synthesized and applied to ultra trace nickel determination. The methodology was validated by the standard addition method and satisfactorily applied to nickel determination in urine without previous treatment, coming from subjects with different smoking addiction levels and second hand smokers. Within-day precision was better than 0.011 CV. The reproducibility （between-days precision） was also evaluated over 3 days by performing six determinations each day with a CV of 0.025. The proposed methodology represents a promising approach in the area of biological monitoring due to its low operation cost, simplicity of instrumentation, high sampling speed and non-polluting solvents. Obtained results of urinary nickel concentration were successfully correlated with the tobacco addiction.