Residential radon and lung cancer risk in a high-exposure area of Gansu Province, China

In the general population, evaluation of lung cancer risk from radon in houses is hampered by low levels of exposure and by dosimetric uncertainties due to residential mobility. To address these limitations, the authors conducted a case-control study in a predominantly rural area of China with low mobility and high radon levels. Included were all lung cancer cases diagnosed between January 1994 and April 1998, aged 30-75 years, and residing in two prefectures. Randomly selected, population-based controls were matched on age, sex, and prefecture. Radon detectors were placed in all houses occupied for 2 or more years during the 5-30 years prior to enrollment. Measurements covered 77% of the possible exposure time. Mean radon concentrations were 230.4 Bq/m(3) for cases (n = 768) and 222.2 Bq/m(3) for controls (n = 1,659). Lung cancer risk increased with increasing radon level (p < 0.001). When a linear model was used, the excess odds ratios at 100 Bq/m(3) were 0.19 (95% confidence interval: 0.05, 0.47) for all subjects and 0.31 (95% confidence interval: 0.10, 0.81) for subjects for whom coverage of the exposure interval was 100%. Adjusting for exposure uncertainties increased estimates by 50%. Results support increased lung cancer risks with indoor radon exposures that may equal or exceed extrapolations based on miner data.     

Occupation and lung cancer risk in Leningrad Province, Russia

To investigate the association between occupation and lung cancer risk in Leningrad Province, Russia, we identified 540 pathologically diagnosed lung cancer cases (474 males and 66 females) and 582 controls (453 males and 129 females) from the 1993-1998 autopsy records of the 88 state hospitals of the Province. Lifetime occupational histories were obtained from personal records coded according to the standard Russian occupational classification system. Lung cancer risk was increased in workers in the manufacturing industry, particularly in the food industry and wholesale/retail trade and in the miscellaneous manufacturing industry. An increased risk was also found in subjects employed in chemical and metal production for 10 years or more. When we considered the association between specific occupations and lung cancer, waste incineration operators and loaders exhibited an excess risk that increased with employment duration. The present study, which is the first to evaluate the risk of lung cancer by occupation in Russia, suggests the presence in Leningrad Province of exposure in the workplace to lung carcinogens that require further characterization to develop targeted and effective preventive measures.     

Menstrual and reproductive factors and risk of lung cancer among Chinese women,Eastern Gansu Province, 1994-1998

There are suggestions that women have higher relative risks of lung cancer than men given similar levels of tobacco exposure, implying that sex-related hormones may influence lung cancer risk. We evaluated the association between lung cancer risk and menstrual and reproductive factors on a subset of self-responding females in a population based case-control study in Eastern Gansu Province, China, 1994-1998. The analysis included 109 incident lung cancer cases and 435 controls selected from the census list and frequency matched to cases on age and prefecture. Odds ratios were lower for later ages at menarche (trend, P = 0.015) and later ages at menopause (trend, P = 0.074). Despite limitations, these findings suggest a possible role of hormones in the etiology of lung cancer in females.     

Lactation reduces breast cancer risk in Shandong Province, China

Results from studies of western populations investigating lactation and breast cancer risk have been inconsistent. To examine this issue, the authors conducted a hospital-based case-control study in Shandong Province, China, in 1997-1999. A total of 404 cases and an equal number of controls were included. Detailed information regarding lactation, menstruation, and reproduction was collected through in-person interview. The authors found a significant inverse association between duration of lactation and breast cancer risk. For women who breastfed for more than 24 months per child, the odds ratio was 0.46 (95% confidence interval (CI): 0.27, 0.78) when compared with those who breastfed for 1-6 months per child. A significantly reduced risk of breast cancer was also found for those whose lifetime duration of lactation totaled 73-108 months (odds ratio = 0.47, 95% CI: 0.23, 0.95) and for those who breastfed for > or =109 months (odds ratio = 0.24, 95% CI: 0.11, 0.53). The test for trend was statistically significant for both mean duration of lactation per child (p = 0.02) and lifetime duration of lactation (p = 0.00). Further stratification by menopausal status resulted in the same conclusion. These data suggest that prolonged lactation reduces breast cancer risk.     

Smoking and other risk factors for lung cancer in Xuanwei, China

In Xuanwei County, Yunnan Province, lung cancer mortality rates are among the highest in China in both males and females. Previous studies have shown a strong association of lung cancer mortality with indoor air pollution from 'smoky' coal combustion. In the present case-control study, 110 newly-diagnosed lung cancer patients and 426 controls were matched with respect to age, sex, occupation (all subjects were farmers), and village of residence (which provided matching with respect to fuel use). This design allowed assessment of known and suspected lung cancer risk factors other than those mentioned above. Data from males and females were analysed by conditional logistic regression. In females who do not smoke, the presence of lung cancer was statistically significantly associated with chronic bronchitis (odds ratio [OR] = 7.37, 95% confidence interval [Cl]: 2.40-22.66) and family history of lung cancer (OR 4.18, 95% Cl: 1.61-10.85). Females' results also suggested an association of lung cancer with duration of cooking food (OR 1.00, 9.18 and 14.70), but not with passive smoking (OR 0.77, 95% Cl: 0.30-1.96). In males, lung cancer was significantly associated with chronic bronchitis (OR 7.32, 95% Cl: 2.66-20.18), family history of lung cancer (OR 3.79, 95% Cl: 1.70-8.42), and personal history of cooking food (OR 3.36, 95% Cl: 1.27-8.88). In males a dose-response relationship of lung cancer with smoking index (years of smoking*amount of smoking) was shown by risks of 1.00, 2.61, 2.17 and 4.70.     

Occupation and lung cancer risk among women in Northern China

Lifetime occupational histories were obtained in a case-control study of 965 female lung cancer patients and 959 controls selected from the general population in Shenyang and Harbin, People's Republic of China, where most women have worked outside the home. After adjusting for smoking, we found a significantly increased risk of lung cancer associated with employment involving the manufacture of transportation equipment (OR = 1.6, 95% CI = 1.0, 2.6), in particular the manufacturing of automobiles (OR = 3.0, 95% CI = 1.4, 6.4). Metal smelting and treatment workers were at an increased risk of lung cancer (OR = 1.5, 95% CI = 1.0, 2.1); the highest risks were observed among metal surfacers (OR = 3.1, 95% CI = 1.1, 9.0) and currently employed foundry workers (OR = 13.0, 95% CI = 1.7, 99.4). On the other hand, about a 50% decreased risk of lung cancer was observed among those employed in textile industries or as leaders of state and party organizations. Based on self-reports, exposures to coal dust and smoke from burning fuel at the workplace were also significant risk factors. The findings were similar when the analyses were confined to nonsmokers and were comparable across the major cell types of lung cancer. © 1993 Wiley-Liss, Inc.     

肺部弥漫性病变中肺癌和肺结核的CT影像鉴别

肺部弥漫性病变是指病变累及双肺全部或几乎全部,并在胸片或CT上形成各种影像表现的肺部疾病的统称,是一种非特异性术语.肺部弥漫性病变病种繁多,而且许多疾病的临床症状及体征较为相似,其胸片表现、CT征象也大同小异,给诊断和鉴别诊断带来极大困难,所以肺部弥漫性病变的诊断一直是临床值得深入研究的课题.随着CT特别是多层螺旋CT高分辨扫描(HRCT)的广泛应用,可以较清楚地显示肺小叶的细微结构,为肺部弥漫性病变的诊断和鉴别诊断提供了更为详尽的影像信息,是诊断肺部弥漫性病变的首选方法.     

甘肃省榆中县2003-2008年肺结核回顾性调查研究

目的通过甘肃省榆中县2003-2008年肺结核病分析,评估国家结核病控制项目效果,为制定农村结核病防治措施提供科学依据。方法选择榆中县2003-2008年国家结核病管理信息系统中所有报告新发确诊肺结核病例1259例,收集这些病例来源、年龄、性别、职业、诊断、治疗等信息进行回顾性调查分析。结果1.该县2003-2008年肺结核病年报告发病率稳定在45～59/10万,男性发病率高于女性（P〈0.001）,年龄越大发病率越高（P〈0.001）,农民发病率高于其他职业（P〈0.001）,山区发病率高于川区（P〈0.001）。2.在1259例新发肺结核病例中,男性62.1%,55岁以上者57.8%,35～54岁者33.8%,农民90.5%,川区54.6%。3.1259例新发报告肺结核病例,治愈1185例（94.1%）,失败43例（3.4%）,迁出或失访21例,全死因死亡10例。结论该结核病项目县肺结核发病率低而治愈率高,通过项目提高农村肺结核病例发现和疗效,实施现代结核病控制策略。     

Serum cholesterol, beta-carotene, and risk of lung cancer.

This paper hypothesizes that beta-carotene mediates the association between low serum cholesterol and increased risk of lung cancer, predicts that the association should be greater in population strata with low intake of beta-carotene than in those with high intake if the hypothesis is correct, and investigates this prediction with data from a 24-year cohort study of 1,960 middle-aged employed men. In the total cohort, serum cholesterol was not related to risk of lung cancer. The relative risk associated with a difference of -1.0 mmol per liter in serum cholesterol was 1.01 (95% confidence interval of 0.80-1.27) after adjustment for cigarette smoking, age, and intake of beta-carotene. In contrast, however, when the study group was restricted to men with intake of beta-carotene less than 5,000 (N = 929) or less than 3,000 IU per day (N = 272), comparable relative risks were 1.10 and 1.21, respectively. Although the 95% confidence intervals for these relative risks were broad and included unity, the result is consistent with expectation. We conclude that the hypothesis warrants further investigation.     

Relative risk and acceleration in lung cancer

For a substance that increases the relative risk of disease, it does not necessarily follow that the proportion of cases due to exposure to the substance is the same as the attributable fraction in the exposed. An alternative explanation is that the substance has accelerated the occurrence of disease and, therefore, played a role in all cases. When the incidence of disease with time follows the Weibull distribution, it is well known that the proportional hazards model and the accelerated failure time model are equivalent. The purpose of this paper is to provide a numerical illustration of the relationship between the relative risk and the acceleration time of occurrence of cases. A Weibull distribution is a good approximation for lung cancer death rates up to the age of 80 years. The numerical relationship between the relative risk and the time by which cases are accelerated is given for lung cancer deaths occurring at ages of 40-75 years with relative risks of 1.01-3. As an example, for a death due to lung cancer at age 60 years in a smoker, relative risks of 2 and 1.1 due to occupational exposure to a substance correspond to accelerations of 5.2 years and 8 months, respectively.     

甘肃省河西走廊地区蚊媒调查

目的 了解河西走廊地区蚊媒传染病传播媒介分布情况,进一步确认河西走廊地区为无流行性乙型脑炎（乙脑）及其他蚊媒传染病地区.方法 采用灯诱法和人工小时法.灯诱法：用功夫小帅牌吸入式诱蚊灯悬挂于每个调查点离地面0.8～1.5 m处,每次开灯诱捕12h;人工小时法：采集者手持电动吸蚊器或口吸吸蚊管在人房、居民区楼道、猪圈、牛棚捕获蚊虫,捕蚊时间一般为30～40 min.结果 共采集蚊虫23 584只,通过初步鉴定,发现该地区蚊虫4属18种.在所捕获蚊虫中,数量最多的生境为畜舍,占捕获总数的76.39％,农户次之,占14.23％,居民区最少,占4.49％.淡色库蚊、刺扰伊蚊为优势蚊种,分别占捕获总数的55.87％和23.04％,几乎分布整个河西5市.未捕获到乙脑主要传播媒介三带喙库蚊,病毒检测未检出乙脑病毒,但在该地区首次发现蚊传黄病毒和辽宁病毒,且病毒阳性检出率较高.结论 河西走廊地区蚊虫种群分布较为广泛,部分水系分布较为丰富的区域种群密度较高;今后应加强该地区蚊虫孳生地清理工作;河西地区蚊虫携带病毒的研究不可懈怠.     

Relation of arsenic exposure to lung cancer among tin miners in Yunnan Province, China.

The relation of mining and smelting exposure to arsenic and lung cancer was studied among tin miners in Yunnan Province in the People's Republic of China. Interviews were conducted in 1985 with 107 living tin miners who had lung cancer and an equal number of age matched controls from among tin miners without lung cancer to obtain information on risk factors for lung cancer including detailed history of employment and tobacco use. Occupational history was combined with industrial hygiene data to estimate cumulative arsenic exposure. Similar methods were also used to estimate radon exposure for simultaneous evaluation in this analysis. The results indicate that subjects in the highest quarter of cumulative arsenic exposure have a relative risk of 22.6 compared with subjects without exposure after adjusting for tobacco and radon exposure, and a positive dose response relation was observed. Simultaneous evaluation of arsenic and tobacco exposure indicates a greater risk for arsenic, whereas simultaneous assessment of arsenic and radon exposure suggests radon to be the greater risk. There is no evidence of synergism between arsenic and tobacco exposure. Among arsenic exposed individuals, cases of lung cancer have longer duration but lower average intensity of arsenic exposure than controls, indicating that duration of exposure to arsenic may be more important than intensity in the aetiology of lung cancer. Finally, risk of lung cancer among workers exposed to arsenic only in mining is only slightly less than for miners whose exposure to arsenic was limited to smelting, although risks are highest when workers were exposed to both mining and smelting.     

Attributed risk to smoking for lung cancer,laryngeal cancer and esophageal cancer

OBJECTIVE: Lung, laryngeal and esophageal cancers have smoking as one of their main risk factors. The objective of this study was to evaluate the population attributed risk (PAR) of smoking for these forms of cancer. METHODS: The study was based in three case-control studies conducted in medium size cities in Brazil. Incident cases of lung cancer, laryngeal cancer and esophageal cancer seen at a hospital setting and diagnosed through biopsy were analyzed; controls were hospitalized patients with another diagnoses. Smoking was the exposure factor measured at three levels: non-smokers, former smokers and smokers, which were defined using a questionnaire applied by trained interviewers. For effect measure, odds ratio was used and the populational attributed risk for smoking was then calculated for a 95% CI. RESULTS: A total of 122 lung cancer cases and 244 controls, 50 cases of laryngeal cancer and 48 cases of esophageal cancer, and 96 controls for both of them were studied. The prevalence of smoking exposure was 34%, which is the overall prevalence of smoking in this city's adult population. Odds ratios (OR) for the PAR analysis were the adjusted OR for confounding variables from each study. Lung cancer PAR was 63% (95% IC, 0.58-0.68) for former smokers and 71% (95%IC, 0.65-0.77) for smokers. Larynx cancer PAR was 74% (95% IC, 0.70-0.78) and 86% (95%IC, 0.81-0.85) for former smokers and smokers, respectively. Esophageal cancer PAR was 54% (95%IC, 0.46-0.62) for smokers. CONCLUSION: Smoking is an avoidable risk factor and smoking cessation could be responsible for significant reductions in the incidence of these three forms of cancer.     

“5·12”地震前后陇南市虫媒传染病流行病学分析

目的调查甘肃省陇南市虫媒传染病在“5·12”地震前后的发病情况,分析地震后虫媒消杀对虫媒传染病的影响。方法收集陇南市2005—2008年流行性乙型脑炎（乙脑）和疟疾发病例数,2005--2009年黑热病的发病例数,计算发病率,分析地震前后虫媒传染病流行病学特点。结果2005--2008年陇南市共报告乙脑164例,年平均发病率为1．20／10万,2008年乙脑发病率与2005--2007年比较差异无统计学意义（P≥0．05）;2005--2009年报告黑热病501例,年发病率为3．68／10万;其发病率男性高于女性（P〈O．001）;2008年黑热病发病率与2007和2009年比较差异无统计学意义（P≥0．05）。2005--2008年报告疟疾7例,年发病率为0．06／10万。武都区和文县是陇南地区虫媒传染病的主要流行区。结论乙脑和黑热病是陇南市常见虫媒传染病;地震后虫媒传染病发病率未上升,可能与地震后的虫媒消杀工作有密切关系。     

早产儿肺及早产儿肺疾病的影像学评估价值

呼吸系统疾病已成为导致我国早产儿死亡的主要原因之一。由于产前糖皮质激素促胎肺成熟治疗、肺表面活性物质(PS)及各种类型呼吸支持技术等的应用,临床诊治该类疾病的策略日趋成熟,对于早产儿呼吸系统常见疾病的诊治,大多具备各自的指南和临床路径。目前临床对于该领域的研究热点,多集中于早产儿肺及其疾病的基因研究、早期干预方式的选择和精准化诊治等方面。笔者拟就早产儿肺及早产儿肺疾病的病理生理基础、影像学表现及其转归的最新研究进展进行阐述,以探讨影像学检查在早产儿肺及其肺疾病中的临床应用价值,辅助临床实现对早产儿肺疾病的精准化诊治。     

Relation of radon exposure and tobacco use to lung cancer among tin miners in Yunnan Province, China

We studied the relation of radon exposure and tobacco use to lung cancer among tin miners in Yunnan Province in the People's Republic of China. Interviews were conducted in 1985 with 107 living tin miners with lung cancer and an equal number of age-matched controls from among tin miners without lung cancer to obtain information on lung cancer risk factors including a detailed history of employment and tobacco use. Occupational history was combined with extensive industrial hygiene data to estimate cumulative working level months (WLM) of radon daughter exposure. Similar data were also used to estimate arsenic exposure for control in the analysis. Results indicate an increased risk of lung cancer for water pipe smoking, a traditional form of tobacco use practiced in 91% of cases and 85% of controls. Ever use of water pipes was associated with a twofold elevation in risk when compared with tobacco abstainers, and a dose-response relation was observed with increasing categories of pipe-year (dose times duration) usage. Estimated WLM of radon exposure varied from 0 to 1,761 among subjects but averaged 515 in cases versus only 244 in controls. Analyses indicated that the persons in the highest quarter of the radon exposure distribution had an odds ratio (OR) = 9.5 (95% confidence interval = 2.7-33.1) compared to persons without radon exposure after controlling for arsenic exposure and other potential confounders. Examination of duration and rate of radon exposure indicated higher risk associated with long duration as opposed to high rate of exposure. Cross-categorizations of radon exposure and tobacco use suggest greater risk associated with radon exposure than tobacco in these workers.