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Background: Lifetime use of bituminous ('smoky') coal is associated with nearly a 100-fold higher risk of lung cancer mortality compared with anthracite ('smokeless') coal use in rural Xuanwei, China, among women. Risk of mortality from ischaemic heart disease (IHD) and stroke for these coal types has not been evaluated.Methods: A cohort of 16 323 non-smoking women in Xuanwei, who were lifetime users of either smoky or smokeless coal, were followed up from 1976 to 2011. We estimated hazard ratios (HRs) and 95% confidence intervals (CI) to evaluate lifetime use of coal types and stoves in the home in relation to risk of IHD and stroke mortality.Results: Among lifetime users of smokeless coal, higher average exposure intensity (≥4 tons/year vs <2.5 tons/year, HR = 7.9, 95% CI = 3.5-17.8; Ptrend =<0.0001) and cumulative exposure (>64 ton-years vs ≤28 ton-years, HR = 6.5, 95% CI = 1.5-28.3; Ptrend =0.003) during follow-up and over their lifetime was associated with increased IHD mortality, and ventilated stove use dramatically reduced this risk (HR = 0.2, 95% CI 0.1-0.5). Higher cumulative exposure to smoky coal during follow-up showed positive associations with IHD mortality, but the evidence for other metrics was less consistent compared with associations with smokeless coal use.Conclusions: Higher use of smokeless coal, which is burned throughout China and is generally regarded to be a cleaner fuel type, is associated with IHD mortality. Use of cleaner fuels or stove interventions may be effective in reducing the increasing burden of IHD in developing regions that currently rely on smokeless coal for cooking and heating. [ABSTRACT FROM AUTHOR]

Background: Since 1970s, Xuanwei in Yunnan province has been one of the towns with highest lung cancer mortality in China. Moreover, the characters of high female lung cancer mortality and sub-regional clustering high lung cancer mortality have not changed. In this study, we further described the exposure situation of risk factors of lung cancer in Xuanwei nowadays, in order to explore the trend of the distribution of lung cancer there., Methods: Firstly we divided the 26 towns of Xuanwei city to high-, median- and low- lung cancer areas by the lung cancer mortality in 2010-2012. We chose 2 towns within each area according to topography and orientation, and randomly picked 4 villages in each town to be our study area. We did a questionnaire about lung cancer related risk factors upon the sample population in the study area. We calculated the exposure percentages of each risk factor, in whole sample population and subgroups, for nowadays and for 10 years ago (only living environmental risk factors), and compared them between areas or time points using standardized rates and the statistical test of standardized rate comparison, or chi-square test., Results: 65%-80% male in the study area has a history of smoking; 60%-90% non-smoker has been exposed to second hand smoke. These situations are worse in high and median lung cancer areas. 50% male in median lung cancer area have coal mining work experience, which is 2 times of the percentages in the other two areas; while 15%-25% people in high lung cancer area have other occupational exposure history to particulate air pollution, which is 3-5 times of the percentages in the other two areas. From ten years ago until nowadays, 80% families in median lung cancer area use 2 tons or more smoky coal per year; more than 90% families burn coal for household heating; more than 60% families suffer from smog in the kitchen during cook; 60% families most frequently use stove in the ground with chimney. Only 20% families in high lung cancer area now use 2 tons or more smoky coal per year. Now 50%-75% families in the study area use 700 kilowatt-hours of electricity per year, much more than ten years ago. 80% residents in low lung cancer area eat fatty or pickled or smoked food at least 3 days per week; while in high and median lung cancer areas the percentages are 50%-60%., Conclusions: According to data obtained in this survey, current distribution of smoky coal use has differed from the distribution of high-, median- and low- lung cancer areas. Tobacco use and second hand smoke, the use of smoky coal and occupational exposure to particulate matters could be the main risk factors for lung cancer in Xuanwei now. The relations between lung cancer and stove type, dietary habit and so on deserve further study.

Objective: To evaluate the completeness of the death registration system, so as to understand the death patterns in Xuanwei., Methods: The investigation on under-reported deaths was conducted in 30 villages selected with a multi-stage random sampling strategy. Participants were asked about changes of their family members (family members born or dead) during past 3 years with door to door visit. Then, death cases obtained in our investigation were matched with those from routine death registration system and under-reported rate of deaths during 2011-2013 was calculated employing capture-recapture method., Results: Total under-reported rate of deaths was 31.88%. For people aged between 0-14, 15-39, 40-69 and 60 above, under-reported rates of death were 33.35%, 34.93%, 29.10%, and 32.88%, respectively. And they were 31.72% and 32.02% for males and females, respectively. There was no significant difference shown in under-reported rates among deaths in different age groups (χ² = 7.24, P = 0.065) and genders (χ² = 0.06, P = 0.803). The under-reported rates in high-mortality, medium-mortality and low-mortality regions were 17.48%, 38.01%, and 36.22%, respectively with a significant difference (χ² = 213.25, P < 0.001). Death in local regions with mortality rate higher than 600.00/10(5), between 400.00/10⁵ and 600.00/10⁵ and lower than 400.00/10⁵ were adjusted with under-reported rates in three regions above respectively. The total adjusted morality rate in Xuanwei during 2011-2013 was 776.47/10⁵. For males and females, they were 918.73/10⁵ and 617.46/10⁵, respectively., Conclusion: Overall under-reported rate of death was high in death registration system in Xuanwei. It was necessary to adjust mortality data reported with under-reported rate of death to estimate death patterns in this area.

The identification of spatial clusters of lung cancer mortality can be a useful instrument in detecting locations with high risk of this disease. This study compared 2 methods for identifying spatial clusters of village-level women lung cancer mortality rates in Xuan Wei. One used a local indicator of spatial association to detect which groups of neighboring villages had lung cancer mortality rates that were significantly related to each other. The other was a spatial scan technique that calculated a maximum likelihood ratio of lung cancer deaths relative to the underlying population in order to identify the group of villages with relatively higher risk. As each technique based its cluster detection process on its own criteria, different clusters of villages were identified. However, the overlapping indicated that the 2 methods illustrated different components of the same clusters. These spatial analytic techniques were complementary to each other and can be used jointly rather than separately., (© 2012 APJPH.)

Objective: To estimate the risk of lung cancer associated with the use of different types of coal for household cooking and heating., Setting: Xuanwei County, Yunnan Province, China., Design: Retrospective cohort study (follow-up 1976-96) comparing mortality from lung cancer between lifelong users of "smoky coal" (bituminous) and "smokeless coal" (anthracite)., Participants: 27,310 individuals using smoky coal and 9962 individuals using smokeless coal during their entire life., Main Outcome Measures: Primary outcomes were absolute and relative risk of death from lung cancer among users of different types of coal. Unadjusted survival analysis was used to estimate the absolute risk of lung cancer, while Cox regression models compared mortality hazards for lung cancer between smoky and smokeless coal users., Results: Lung cancer mortality was substantially higher among users of smoky coal than users of smokeless coal. The absolute risks of lung cancer death before 70 years of age for men and women using smoky coal were 18% and 20%, respectively, compared with less than 0.5% among smokeless coal users of both sexes. Lung cancer alone accounted for about 40% of all deaths before age 60 among individuals using smoky coal. Compared with smokeless coal, use of smoky coal was associated with an increased risk of lung cancer death (for men, hazard ratio 36 (95% confidence interval 20 to 65); for women, 99 (37 to 266))., Conclusions: In Xuanwei, the domestic use of smoky coal is associated with a substantial increase in the absolute lifetime risk of developing lung cancer and is likely to represent one of the strongest effects of environmental pollution reported for cancer risk. Use of less carcinogenic types of coal could translate to a substantial reduction of lung cancer risk.

Background and Objective: Xuanwei county is located at Late Permian coal-accumulating area in eastern Yunnan and western Guizhou, China. The lung cancer mortality rate in Xuanwei county is among the highest in China and has been attributed to exposure to indoor smoky coal emissions that contain very high levels of polycyclic aromatic hydrocarbons (PAHs). Recent years, the pollution and the higher mortality rate of lung cancer has been watched in the area around Xuanwei, and there is no report about whether the epidemic levels and the pathogen of lung cancer in other area of eastern Yunnan is similar to that in xuanwei. The aim of this study is to epidemic levels and cause of lung cancer in coal-producing area in the east of Yunnan province., Methods: 382 study units (nature villages) were selected by stratified cluster random sampling from coalproducing area in eastern Yunnan province, China. The villagers who were aged 30-79 years with no history of lung cancer were enrolled. All the participants received an initial single-view posterior-anterior chest radiograph and administered a questionnaire survey (which involves the information of demography, household and fuel use, lifestyle, tobacco and occupational exposure history, family and personal medical history, etc. The subjects with a positive screen by chest x-ray underwent to have a computed tomography scan of the chest and biopsy examination. The confidence interval of the standardized rate ratio were adopted to evaluate the statistical significance of differences in different regions., Results: 52,833 villagers were surveyed and screened with X-ray. 604 of them were suspicious lung cancer with an initial chest radiograph, 541 underwent CT scan (362 were diagnosed by CT and 109 were diagnosed by histology). The adjusted positive rates for lung cancer screening with CT is 763.08 per 100,000, the age-standardized rate (ASR) with the world standard population is 426.28 per 100,000 (95% confidence interval=381.51/10 per 100,000 to 471.05 per 100,000), 482.78 per 100,000 for man, 387.98 per 100,000 for woman, male-to-female (M:F) rate ratios is 1.24. The intensity of lung cancer had significant difference between different study units. The ASR for lung cancer screening from A, B, C to D areas decreased in turn, and the area A was the highest of all, which was 6.97 times higher than the lowest area D, and the ratio between male and female was increased gradually. The positive rate for lung cancer was related to the distribution of coal and in direct proportion to the amount of smoky coal burning, but not associated with smokeless coal combustion. There are above 80% residents who burned "smoky" coal in indoor firepits which generated very high levels of air pollution. Lung cancer mortality of family members has the same distribution to positive rates of lung cancer screening, and they are in proportion to each other. 85% men smoke 16.12 cigarettes per day, averagely. About 50% of them did the job like coking, mining coal and so forth. Smoking rate of woman is 1.37%, they always did housework such as cooking, raising pigs and so on. Though the smoking and occupational hazard factors were not the major reasons for women to get lung cancer, they were possible reasons for men., Conclusions: In coal-producing area in eastern Yunnan, China, [corrected] lung cancer was associated with exposure to smoky coal emissions and family susceptibility. Smoking, coking and mining were not the major risk factors lead to lung cancer for women.