Lung Cancer Mortality In China Research Articles

Opportunistic Screening With Low-Dose Computed Tomography and Lung Cancer Mortality in China

Despite the recommendations of lung cancer screening guidelines and the evidence supporting the effectiveness of population-based lung screening, a common barrier to effective lung cancer screening is that the participation rates of low-dose computed tomography (LDCT) screening among individuals with the highest risk are not large. There are limited data from clinical practice regarding whether opportunistic LDCT screening is associated with reduced lung-cancer mortality. To evaluate whether opportunistic LDCT screening is associated with improved prognosis among adults with lung cancer in mainland China. This cohort study included patients diagnosed with lung cancer at Weihai Municipal Hospital Healthcare Group, Weihai City, China, from 2016 to 2021. Data were analyzed from January 2022 to February 2023. Data collected included demographic indicators, tumor characteristics, comorbidities, blood indexes, and treatment information. Patients were classified into screened and nonscreened groups on the basis of whether or not their lung cancer diagnosis occurred through opportunistic screening. Follow-up outcome indicators included lung cancer-specific mortality and all-cause mortality. Propensity score matching (PSM) was adopted to account for potential imbalanced factors between groups. The associations between LDCT screening and outcomes were analyzed using Cox regression models based on the matched data. Propensity score regression adjustment and inverse probability treatment weighting were used for sensitivity analysis. A total of 5234 patients (mean [SD] baseline age, 61.8 [9.8] years; 2518 [48.1%] female) with complete opportunistic screening information were included in the analytical sample, with 2251 patients (42.91%) receiving their lung cancer diagnosis through opportunistic screening. After 1:1 PSM, 2788 patients (1394 in each group) were finally included. The baseline characteristics of the matched patients were balanced between groups. Opportunistic screening with LDCT was associated with a 49% lower risk of lung cancer death (HR, 0.51; 95% CI, 0.42-0.62) and 46% lower risk of all-cause death (HR, 0.54; 95% CI, 0.45-0.64). In this cohort study of patients with lung cancer, opportunistic lung cancer screening with LDCT was associated with lower lung cancer mortality and all-cause mortality. These findings suggest that opportunistic screening is an important supplement to population screening to improve prognosis of adults with lung cancer.

Age-period-cohort analysis of lung cancer mortality in China and Australia from 1990 to 2019

Lung cancer (LC) is the leading cause of cancer death in China and Australia, the countries with different socioenvironmental contexts in the Western Pacific Region. Comparing the age-period-cohort effect on LC mortality (LCM) between the two countries can help plan interventions and draw lessons for countries in the region. We collected LCM estimates between 1990 and 2019 from the GBD 2019. Age-period-cohort modelling was applied to compute the net drift, local drift, cross-sectional age curve, longitudinal age curve, and the rate ratios (RRs) of period and cohort. China had a higher LC age-standardized mortality rate than Australia in 2019 (men: 58.10 [95% uncertainty interval (UI): 46.53, 70.89] vs. 30.13 [95% UI: 27.88, 32.31]/100,000 population; women: 22.86 [95% UI: 18.52, 27.52] vs. 17.80 [95% UI: 15.93, 19.34]/100,000 population). Period and cohort effects on LCM improved more markedly among Australian men (RR for period effect, from 1.47 [95% confidence interval (CI) 1.41, 1.53] to 0.79 [95% CI 0.75, 0.84]; RR for cohort effect, from 2.56 [95% CI 2.44, 2.68] to 0.36 [95% CI 0.11, 1.18]) and Chinese women (RR for period effect, from 1.06 [95% CI 1.01, 1.11] to 0.85 [95% CI 0.82, 0.89]; RR for cohort effect, from 0.71 [95% CI 0.65, 0.78] to 0.51 [95% CI 0.26, 1.03]) during the study period and birth cohort. The LCM in Chinese population aged 65 to 79 and Australian women aged 75 to 79 increased. Smoking and particulate matter (PM) contributed most to LCM in China, while smoking and occupational carcinogens contributed most in Australia. Decreasing period and cohort risks for LCM attributable to smoking and PM were more remarkable in Australia than in China. The LCM attributable to occupational carcinogens was higher in Australia than in China, particularly for those aged 60 to 79. Vigorous tobacco and PM control, which brought a substantial decline in LCM in Australia, may help reduce LCM in China. Australia should highlight LC prevention among people with occupational exposure. Chinese aged ≥ 65 and Australian women aged ≥ 75 should be the priorities for LC interventions.

Lung cancer mortality in China: a comparison analysis based on the Global Burden of Disease Study 2017

Background: China has a large population and is experiencing a transition period. Comparing lung cancer (LC) deaths and population attributable fractions (PAFs) of risk factors between China and other countries/regions are essential to inform effective control. Global Burden of Disease (GBD) study provides a unique opportunity for the comparison.Methods: We extracted the number of LC deaths, age-standardized death rates (ASDRs), and the PAFs of risk factors between 1990 and 2017 from the GBD 2017. The annual percentage change (APC) was used to quantify the trends of ASDRs in China and other regions. The relationships of the APC with Socio-demographic Index and baseline of ASDRs were assessed among China and other countries.Results: In 2017, LC ASDRs were 35.38 (95% uncertainty interval (UI): 34.39 to 36.35) and 13.94 (95% UI: 13.53 to 14.36) per 100,000 person-years in men and women worldwide, respectively. It decreased significantly in men (APC: -0.66%, 95% confidence interval (CI): -0.69 to -0.62) but increased significantly in women (APC: 0.31%, 95% CI: 0.26 to 0.36) from 1990 to 2017. LC ASDRs in China increased significantly among both men (APC: 1.12%, 95% CI: 1.03 to 1.2) and women (APC: 0.80%, 95% CI: 0.70 to 0.89). The increased LC deaths among men (312,798) and women (139,115) in China accounted for 59.39% and 43.01% of global increases. The risk factors with the highest PAFs in China were smoking and ambient particulate matter (PM) pollution. The PAF of ambient PM pollution in China ranked 2nd globally. Conclusions: The trends of LC ASDRs and the PAFs of risk factors varied markedly by region, which calls for tailored measures to reduce disease burden and improve health equality. China’s LC death rates were among the highest worldwide and remained on the rise. PM and tobacco control should be China’s intervention priorities.

Lung cancer mortality associated with PM2.5 in China: a national study based on county level

Background: The relative risk (RR) of PM2.5 in lung cancer mortality (LCM) may vary spatially in China. However, previous studies applying global regression model have been unable to capture such variation. The research aimed to employ a geographically weighted Poisson regression (GWPR) model to estimate the county-specific RRs of LCM among the elderly (≥65 years) related to PM2.5 and predict LCM in China.Methods: We obtained LCM data between 2013 and 2015 from the Chinese National Death Surveillance. We linked annual mean concentrations of PM2.5 between 2000 and 2004 with LCM using GWPR model at the county level, after adjusting for smoking and socioeconomic covariates. County-specific coefficients from GWPR were used to predict LCM under different scenarios of PM2.5 concentration according to the WHO Air Quality Guidelines. Results: The magnitude of the association between PM2.5 and LCM varied with county. The medians of county-specific RRs of LCM among elderly men and women were 1.52 (range: 0.90, 2.40) and 1.49 (range: 0.88, 2.56) for each 10μg/m3 increment in PM2.5, respectively. Higher RRs of PM2.5 among elderly men were located at Southwest and South China, and higher RRs among elderly women were located at Northwest, Southwest, and South China. Our research estimated that around 411,201 (men: 269,389; women: 141,812) LCM among the elderly would be avoided in 2034, if PM2.5 concentration met the WHO guideline (10μg/m3). Conclusions: The relative importance of PM2.5 in LCM differed by county. The results could help the government design tailored and efficient interventions. Stringent PM2.5 control is urgently needed to reduce LCM in China.

County-level variation in the long-term association between PM2.5 and lung cancer mortality in China

IntroductionThe relative risk (RR) of long-term exposure to PM2.5 in lung cancer mortality (LCM) may vary spatially in China. However, previous studies applying global regression have been unable to capture such variation. We aimed to employ a geographically weighted Poisson regression (GWPR) to estimate the RRs of LCM among the elderly (≥65 years) related to long-term exposure to PM2.5 and the LCM attributable to PM2.5 at the county level in China. MethodsWe obtained annual LCM in the elderly between 2013 and 2015 from the National Death Surveillance. We linked annual mean concentrations of PM2.5 between 2000 and 2004 with LCM using GWPR model at 148 counties across mainland China, adjusting for smoking and socioeconomic covariates. We used county-specific GWPR models to estimate annual average LCM in the elderly between 2013 and 2015 attributable to PM2.5 exposure between 2000 and 2004. ResultsThe magnitude of the association between long-term exposure to PM2.5 and LCM varied with county. The median of county-specific RRs of LCM among elderly men and women was 1.52 (range: 0.90, 2.40) and 1.49 (range: 0.88, 2.56) for each 10 μg/m3 increment in PM2.5, respectively. The RRs were positively significant (P < 0.05) at 95% (140/148) of counties among both elderly men and women. Higher RRs of PM2.5 among elderly men were located at Southwest and South China, and higher RRs among elderly women were located at Northwest, Southwest, and South China. There were 99,967 and 54,457 lung cancer deaths among elderly men and women that could be attributed to PM2.5, with the attributable fractions of 31.4% and 33.8%, respectively. ConclusionsThe relative importance of long-term exposure to PM2.5 in LCM differed by county. The results could help the government design tailored and efficient interventions. More stringent PM2.5 control is urgently needed to reduce LCM in China.

Lung Cancer Mortality in China: Spatial and Temporal Trends Among Subpopulations

Background: Little is known regarding spatial and temporal trends of lung cancer mortality (LCM) among subpopulations in China. The study identified the changing spatial and temporal patterns of LCM across China as a whole and in different subpopulations (ie., region, age, and sex). Methods: The data on LCM for the period of 2006 to 2015 by region, age, and sex were extracted from the Chinese National Death Surveillance. Joinpoint regression and seasonal decomposition were used to assess the temporal trends of LCM. Geographic information system and spatial kriging interpolation were used to examine the spatial distributions of LCM. Findings: LCM was highest in men aged 70+ (annual average mortality rate 397·2 (95%CI (394·6-399·8)) per 100,000 person-years). LCM rate in men aged 30 to 49 significantly declined from 2009 to 2015 (annual percentage change: -2·7%, P<0·05). However, LCM continued to rise in men aged 70+ and women aged 50+ in the east, men and women aged 50 to 69 in the south, and most groups in the southwest. Among provincial capital cities, Shenyang, Changsha, and Hohhot had the highest ten-year average LCM rates for men aged 30 to 49, 50 to 69, and 70+, respectively, while among all ages of women, Harbin had the highest ten-year average LCM rates. When dividing the period by 5 years, the odds of the increases in LCM in men and women aged 30 to 49 and 50 to 69 decreased by 3% to 7% with the longitudes increasing by 1° (OR ranged from 0·93 (95%CI 0·90-0·95) to 0·97 (95%CI 0·95-0·99)), and decreased by 5% to 6% with the latitudes increasing by 1° (OR ranged from 0·94 (95%CI 0·91-0·97) to 0·95 (95%CI 0·92-0·98)). Interpretation: Disparities in the spatial and temporal patterns of LCM among different subpopulations support the need for long-term LC surveillance covering larger geographical areas in China and the need for exploration of possible socio-environmental drivers in a spatiotemporal context. Further investigation into the potential risk factors for rising LCM are urgently required in the east, south, and southwest of China. Funding Statement: For continuous support and assistance, we thank Peng Yin, Jiangmei Liu, and Yunning Liu (National Center for Chronic and Noncommunicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention). We thank all research staff from local Center for Disease Control and Prevention for collection of data. N Wang was supported by the Queensland University of Technology Postgraduate Research Award and Queensland University of Technology Higher Degree Research International Tuition Fee Sponsorship. K Mengersen is supported by the ARC Center of Excellence in Mathematics and Statistical Frontiers. M Kimlin is supported through a Cancer Council Queensland Professorial Chair. W Hu is supported by ARC future fellowship (FT140101216). Declaration of Interests: We declare no competing interests. Ethics Approval Statement: The study has been approved by the Human Research Ethics Committee of Queensland University of Technology (Reference No. 1700001107).

Lung Cancer Mortality in China: Spatial and Temporal Trends Among Subpopulations

This study aimed to identify changing spatial and temporal trends of lung cancer mortality rates (LCMRs) among subpopulations in China (according to region, age, and sex). Data on LCMRs from 2006 to 2015 were extracted from the Chinese National Death Surveillance. Joinpoint regression and seasonal decomposition were used to assess the temporal trends. A geographic information system and spatial kriging interpolation were used to examine the spatial trends. LCMRs in men aged 30 to 49 years significantly declined nationally from 2009 to 2015 (annual percentage change, -2.7%; P< .05), but they continued to rise in men aged≥ 70 years and women aged≥ 50 years in the east, people aged 50 to 69 years in the south, and most groups in the southwest. Among provincial capital cities, Shenyang, Changsha, and Hohhot had the highest 10-year average LCMR for men aged 30 to 49 years, 50 to 69 years, and≥ 70 years, respectively; among all ages of women, Harbin had the highest average LCMR. Over the 10 years, the odds of the increases in LCMRs in men and women aged 30 to 69 years decreased by 3%to 7%with the longitudes or latitudes increasing by 1° (ORs ranged from 0.93 [95%CI, 0.90-0.95) to 0.97 [95%CI, 0.95-0.99]). Disparities in the spatial and temporal trends of LCMRs among subpopulations highlight the need for investigation into potential drivers, especially for the east, south, and southwest of China. These findings may help health authorities target interventions to those most in need to reduce the lung cancer burden in China.

Blockage of TGF-α Induced by Spherical Silica Nanoparticles Inhibits Epithelial-Mesenchymal Transition and Proliferation of Human Lung Epithelial Cells.

Background. Xuanwei City in Yunnan province has been one of the towns with highest lung cancer mortality in China. The high content of amorphous silica in the bituminous coal from Xuanwei of Yunnan is mainly present as irregular and spherical silica nanoparticles (SiNPs). It has been reported that silica nanoparticles in bituminous coal correlated with the high incidence of lung cancer in Xuanwei. To explore the role and mechanism of SiNPs in the tumorigenesis of lung cancer in Xuanwei, human mononuclear cells (THP-1) and human bronchial epithelial cells (BEAS-2B) were cocultured in a transwell chamber. Combined with Benzo[a]pyrene-7, 8-dihydrodiol-9, and 10-epoxide (BPDE), SiNPs could significantly promote the proliferation and Epithelial-Mesenchymal Transition (EMT) and inhibit apoptosis of BEAS-2B cells and induce the release of TGF-α from THP-1 cells. After neutralizing TGF-α with antibody, the proliferation and EMT were decreased and enhanced apoptosis of BEAS-2B cells. Furthermore, the results showed that TGF-α in the sera of patients with lung adenocarcinoma in Xuanwei were significantly higher than in patients with benign pulmonary lesions in Xuanwei and those with lung adenocarcinoma in outside of Xuanwei of Yunnan. Taken together, our study found that SiNPs promoted the proliferation and EMT of BEAS-2B cells by inducing the release of TGF-α from THP-1 cells.

Estimating the spatial distribution of environmental suitability for female lung cancer mortality in China based on a novel statistical method.

Lung cancer as one of the major causes of cancer mortality has been demonstrated to be closely related to the ambient atmospheric environment, but little has been done in the synthetic evaluation of the linkage between cancer mortality and combined impact of ambient air pollution and meteorological conditions. The present study determined the environmental suitability for female lung cancer mortality associated with air contaminants and meteorological variables. A novel fuzzy matter-element method was applied to identify the spatial distribution and regions for the environmental suitability for the female lung cancer mortality across China in 2013. The membership functions between the cancer mortality and 6 environmental factors, including PM2.5, NO2, SO2, PM10, the annual mean wind speed, and mean temperature, were generated and the weights of each of the environmental factors were established by the maximum entropy (MaxEnt) model. We categorized the environmental suitability combined with GIS spatial analysis into three zones, including low-suitable, medium-suitable, and high-suitable region where the cancer mortality ranging from low to high rate was identified. These three zones were quantified by the MaxEnt model taking different air pollutants and meteorological variables into consideration. We identified that NO2 was a most significant factor among the 6 environmental factors with the weight of 24.88%, followed by the annual mean wind speed, SO2, and PM2.5. The high-suitable area, mainly in the North China Plain which is a most heavily contaminated region by air pollution in China, covers 1.6195 million square kilometers, accounting for 17.85% of the total area investigated in this study. Identification of the impact of various environmental factors on cancer mortality in the different suitable area provides a scientific basis for the environmental management, risk assessment, and lung cancer control.

Risk Factors of Lung Cancer in Xuanwei, Yunnan Province, China

背景与目的自1970年代至今，云南省宣威市始终是我国肺癌高发地区之一，且其女性高发、地区聚集性高发的特征未发生过改变。本研究目的在于进一步关注宣威市普通居民肺癌高发危险因素暴露的变化情况，以预测未来肺癌分布特征。方法根据2010年-2012年肺癌死亡率将宣威市26个乡镇划分为高、中、低发区后，根据地形和方位选取6个乡镇（高中低发区各2个），并从每个乡镇中随机抽取4个行政村作为调查点。对调查点中居民样本人群进行肺癌危险因素面对面调查。计算高、中、低发区人群危险因素暴露率，以及性别、年龄别亚组人群暴露率，其中生活环境方面危险因素计算现在和十年前。采用标化率和标化率比较的统计学检验或卡方检验，比较区域间或两时间点暴露水平的高低。结果研究地区65%-80%的男性有吸烟史，60%-90%的从未吸烟者有二手烟暴露史。烟草使用和二手烟暴露均是在肺癌高、中发区明显严重于低发区。中发区50%的男性有煤矿工作经历，是高、低发区的2倍；而高发区15%-25%的人有其他职业烟尘暴露史，是中、低发区的3倍-5倍。从十年前到现在，中发区都有近80%的家庭每年使用2吨或更多烟煤，有超90%的家庭使用燃煤取暖，有60%多的家庭做饭时厨房油烟多，有60%的家庭日常最常使用有烟囱地炉。高发区目前倒只有20%的家庭大量使用烟煤。整个研究地区50%-75%的家庭每年使用700度或更多电，比十年前用电量大增。低发区80%的人经常吃高油脂或腌制熏制食品，高、中发区为50%-60%。结论从本次调查数据来看，目前烟煤使用情况的分布与肺癌高中低发区的分布已不一致。烟草流行包括二手烟暴露，烟煤使用，职业暴露可能是当前宣威肺癌仍旧高发的原因。炉灶类型、饮食习惯等危险因素与宣威肺癌间的相关性值得进一步研究。

Spatiotemporal Variations in Lung Cancer Mortality in China between 2006 and 2012: A Multilevel Analysis.

We investigated temporal trends and geographical variations in lung cancer mortality in China from 2006 to 2012. Lung cancer mortality counts for people aged over 40 years were extracted from the China Mortality Surveillance System for 161 disease surveillance points. Negative binomial regression was used to investigate potential spatiotemporal variation and correlations with age, gender, urbanization, and region. Lung cancer mortality increased in China over the study period from 78.77 to 85.63 (1/100,000), with higher mortality rates evident in men compared to women. Median rate ratios (MRRs) indicated important geographical variation in lung cancer mortality between provinces (MRR = 1.622) and counties/districts (MRR = 1.447). On average, lung cancer mortality increased over time and was positively associated with county-level urbanization (relative risk (RR) = 1.15). Lung cancer mortality seemed to decrease in urban and increase in rural areas. Compared to the northwest, mortality was higher in the north (RR = 1.98), east (RR = 1.87), central (RR = 1.87), and northeast (RR = 2.44). Regional differences and county-level urbanization accounted for 49.4% and 8.7% of provincial and county variation, respectively. Reductions in lung cancer mortality in urban areas may reflect improvements in access to preventive healthcare and treatment services. Rising mortality in rural areas may reflect a clustering of risk factors associated with rapid urbanization.

Lung Cancer Mortality Trends in China from 1988 to 2013: New Challenges and Opportunities for the Government.

Background: As lung cancer has shown a continuously increasing trend in many countries, it is essential to stay abreast of lung cancer mortality information and take informed actions with a theoretical basis derived from appropriate and practical statistical methods. Methods: Age-specific rates were collected by gender and region (urban/rural) and analysed with descriptive methods and age-period-cohort models to estimate the trends in lung cancer mortality in China from 1988 to 2013. Results: Descriptive analysis revealed that the age-specific mortality rates of lung cancer in rural residents increased markedly over the last three decades, and there was no obvious increase in urban residents. APC analysis showed that the lung cancer mortality rates significantly increased with age (20–84), rose slightly with the time period, and decreased with the cohort, except for the rural cohorts born during the early years (1909–1928). The trends in the patterns of the period and cohort effects showed marked disparities between the urban and rural residents. Conclusions: Lung cancer mortality remains serious and is likely to continue to rise in China. Some known measures are suggested to be decisive factors in mitigating lung cancer, such as environmental conservation, medical security, and tobacco control, which should be implemented more vigorously over the long term in China, especially in rural areas.

Characteristics and Prediction of Lung Cancer Mortality in China from 1991 to 2013.

To describe and analyze the epidemiological characteristics of lung cancer mortality in China from 1991 to 2013, forecast the future five-year trend and provide scientific evidence for prevention and management of lung cancer. Mortality data for lung cancer in China from 1991 to 2013 were used to describe epidemiological characteristics. Trend surface analysis was applied to analyze the geographical distribution of lung cancer. Four models, curve estimation, time series modeling, gray modeling (GM) and joinpoint regression, were performed to forecast the trend for the future. Since 1991 the mortality rate of lung cancer increased yearly. The rate for males was higher than that for females and rates in urban areas were higher than in rural areas. In addition, our results showed that the trend will continue to increase in the ensuing 5 years. The mortality rate increased from age 45-50 and peaked in the group of 85 years old. Geographical analysis indicated that people living in northeast China provinces and the coastal provinces in eastern China had a higher mortality rate for lung cancer than those living in the centre or western Chinese provinces. The standardized mortality rate of lung cancer has constantly increased from 1991 to 2013, and been predicted to continue in the ensuing 5 years. Further efforts should be concentrated on education of the general public to increase prevention and early detection. Much better prevention and management is needed in high mortality areas (northeastern and eastern parts of China) and high risk populations (45-50-year-olds).

Ambient air pollution and lung disease in China: health effects, study design approaches and future research.

Ambient air pollution in China has worsened following dramatic increases in industrialization, automobile use and energy consumption. Particularly bothersome is the increase in the PM2.5 fraction of pollutants. This fraction has been associated with increasing rates of cardio-respiratory disease in China and elsewhere. Ambient pollutant levels have been described in many of China's cities and are comparable to previous levels in southern California. Lung cancer mortality in China has increased since the 1970s and has been higher in men and in urban areas, the exact explanation for which has not been determined. The estimation of individual risk for Chinese citizens living in areas of air pollution will require further research. Occupational cohort and case-control designs each have unique attributes that could make them helpful to use in this setting. Other important future research considerations include detailed exposure assessment and the possible use of biomarkers as a means to better understand and manage the threat posed by air pollution in China.

Origin of minerals and elements in the Late Permian coals, tonsteins, and host rocks of the Xinde Mine, Xuanwei, eastern Yunnan, China

This paper reports the mineralogical and geochemical compositions of the Late Permian C2 and C3 coals (both medium volatile bituminous coal) from the Xinde Mine, near Xuanwei in eastern Yunnan, which is located close to the area with the highest female lung cancer mortality in China. The two coals are characterized by high ash yields and low sulfur contents. Three factors, including sediment-source region, multi-stage volcanic ash generation, and multi-stage hydrothermal fluid injections, were responsible for variations in the geochemical and mineralogical compositions of the Xinde coals.Trace elements, including V, Sc, Co, Ni, Cu, Zn, Se, Zr, Nb, Hf, and Ta, are enriched in the coals and were mainly derived from the sediment-source Kangdian Upland region. Major minerals in the samples of coal, roof, floor and non-coal sediment partings include quartz, kaolinite, and chamosite, as well as interstratified illite/smectite and anatase. Chamosite in the coal was derived from reactions between kaolinite and Fe–Mg-rich hydrothermal fluids. However, chamosite in the roof strata was directly precipitated from Fe–Mg-rich hydrothermal fluids or was derived from the alteration of precursor minerals (e.g., biotite) by hydrothermal fluids. Quartz in some samples is very high, especially in the roof strata of the C2 and C3 coal. Such high quartz, along with minor minerals including pyrite, chalcopyrite, sphalerite, calcite, celestite, vanadinite, barite, clausthalite and silicorhabdophane, were derived from multi-stage hydrothermal fluids.The floors of both the C2 and C3 coal seams are fully-argillized fine-grained tuffaceous claystone and the immediate roof of the C2 coal is argillized coarse-grained tuff. The original materials of the floors and roofs of these coal seams were high-Ti alkali basaltic volcanic ashes, as indicated by high TiO2, Nb, and siderophile elements, and the distribution patterns of rare earth elements.Two intra-seam tonstein layers in the C3 coal were identified based on their lateral persistence, mineralogical mode of occurrence and composition, as well as their elemental composition. The tonsteins are dominated by kaolinite, with minor quartz and possibly mixed-layer illite/smectite. Both tonsteins were derived from dacitic magma. The ratios of Nb/Ta, Zr/Hf, and U/Th are much lower in tonsteins than in the adjacent coal benches, which is attributed to the hydrothermal leaching.

Association between long-term exposure to outdoor air pollution and mortality in China: A cohort study

No prior cohort studies exist in China examining the association of outdoor air pollution with mortality. We studied 70,947 middle-aged men and women in the China National Hypertension Survey and its follow-up study. Baseline data were obtained in 1991 using a standard protocol. The follow-up evaluation was conducted in 1999 and 2000. Annual average air pollution exposure between 1991 and 2000, including total suspended particle (TSP), sulfur dioxide (SO2) and nitrogen oxides (NOx), were estimated by linking fixed-site monitoring data with resident zip code. We examined the association of air pollution with mortality using proportional hazards regression model. We found significant associations between air pollution levels and mortality from cardiopulmonary diseases and from lung cancer. Each 10μg/m3 elevation of TSP, SO2 and NOx was associated with a 0.9% (95%CI: 0.3%, 1.5%), 3.2% (95%CI: 2.3%, 4.0%), and 2.3% (95%CI: 0.6%, 4.1%) increased risk of cardiovascular mortality, respectively. We found significant effects of SO2 on mortality after adjustment for TSP. Conclusively, ambient air pollution was associated with increased cardiopulmonary and lung cancer mortality in China. These data contribute to the scientific literature on long-term effects of air pollution for high exposure settings typical in developing countries.