Lung cancer and indoor air pollution in rural china

PURPOSE: Indoor air pollution has been linked with lung cancer in China. In contrast to previous studies conducted in urban areas with high levels of industrial pollution, we undertook a lung cancer case-control study in a rural area of China, where residents live in underground dwellings. We evaluated the effects of radon, wood and coal combustion, cooking oil fumes, and environmental tobacco smoke on lung cancer risk.METHODS: We enrolled 886 lung cancer cases (656 males, 230 females) diagnosed between 1994-98, aged 30-75 years and 1765 frequency matched population-based controls from two prefectures in Gansu Province in Northwestern China. We conducted interviews with subjects or next of kin on smoking, housing characteristics, fuel use and cooking practices. Year-long radon detectors were placed in current and former homes of subjects.RESULTS: Subjects primarily used coal (22%), wood (56%) or a combination of both (22%) for heating. Odds Ratios (OR) for lung cancer rose with increasing percent of time that coal was used to heat homes over the past 30 years (ORs = 1.00, 1.17, 1.35, 1.23 compared to wood only, adjusted to smoking, P for trend = 0.025). Among non-smoking females and males, the OR for ever exposed to environmental tobacco smoke was 1.19, 95% CI = 0.7-2.0 with a significant trend for increasing years of exposure. Fumes from cooking with rapeseed oil increased the risk of lung cancer (OR = 1.56, 95% CI = 1.0-2.5) among non-smoking women. Among these women, occasional and frequent eye and throat irritation during cooking appeared to be associated with increased risk of lung cancer (ORs = 1.00, 1.42, 2.28, p trend < 0.01), whereas, increasing level of smokiness during cooking did not appear to affect risk.CONCLUSIONS: There is a suggestion that coal used for heating, environmental tobacco smoke, and cooking oil fumes contribute to the risk of lung cancer in this rural area of China.     

Nutrient intake among Chinese women living in Shanghai, China

It has been increasingly recognized that dietary factors play a major role in the development of chronic diseases, including cancers and CVD. The identification of patterns of nutrient intake in populations with different disease incidence will be helpful in understanding the diet and disease association. The present report describes nutrient intake in 74,810 Chinese women, aged between 40 and 70 years, who participated in a population-based cohort study in Shanghai from 1997 to 2000. A food frequency questionnaire was used to derive estimates of nutrient intakes. The average daily energy intake was 7027.8 kJ in the study population, with protein, fat and carbohydrates contributing 15.9%, 15.6% and 68.5%, respectively. Factors, including younger age, higher income, attainment of education at the college level or above, being married or holding a professional job, were related to higher intake levels of most nutrients. The present results highlight the need for continuing to promote public health strategies aimed at improving the diets of women from both older and lower socio-demographic backgrounds, and in the meantime, continuing to help address the current dearth of data on nutrient intakes for middle-aged and elderly urban Chinese women.     

Preexisting lung disease and lung cancer among nonsmoking women.

Preexisting lung disease was examined as a risk factor for lung cancer in a population-based, case-control study of nonsmoking women in Missouri conducted between June 1, 1986, and April 1, 1991. A history of lung disease was reported by approximately 41% of 618 cases and 35% of 1,402 controls (odds ratio (OR) = 1.2; 95% confidence interval (Cl) 1.0-1.5. The risk was more pronounced when next-of-kin interviews were excluded (OR = 1.5). Previous lung disease was significantly related both to adenocarcinoma (OR = 1.4), which accounted for 62% of the cancers, and to all other cell types of lung cancer combined (OR = 1.8). Despite having discontinued smoking for more than 15 years, long-term ex-smokers were at a 2.2-fold risk of lung cancer compared with lifetime nonsmokers. Among lifetime nonsmokers, significant risks were noted for asthma (OR = 2.7) and pneumonia (OR = 1.5). Emphysema (OR = 2.6) and tuberculosis (OR = 2.0) were also significantly related to lung cancer, but only among former smokers. Chronic bronchitis was linked to elevated risks of nonadenocarcinomas only (OR = 2.3). Pleurisy was not reported more frequently by cases than by controls. Approximately 16% of all lung cancers among nonsmoking women could be attributed to previous lung diseases, most notably asthma, pneumonia, emphysema, and tuberculosis.     

A population-based case-control study of lung cancer and green tea consumption among women living in Shanghai, China.

Epidemiologic evidence regarding the association between the consumption of green tea and lung cancer is limited and inconclusive, although experimental studies have shown consistently that tea preparations and tea polyphenols may inhibit the induction of a variety of cancers, including lung cancer. In this population-based case-control study, we examined the association between past consumption of green tea and the risk of lung cancer. We identified 649 incident cases of primary lung cancer among women diagnosed from February 1992 through January 1994 using the population-based Shanghai Cancer Registry. We randomly selected a control group of 675 women from the Shanghai Residential Registry, frequency-matched to the expected age distribution of the cases. Green tea consumption was ascertained through face-to-face interviews. We estimated adjusted odds ratios (ORs) and 95% confidence intervals (95% CIs) using unconditional logistic regression. Among nonsmoking women, consumption of green tea was associated with a reduced risk of lung cancer (OR = 0.65; 95% CI = 0.45-0.93), and the risks decreased with increasing consumption. We found little association, however, among women who smoked (OR = 0.94; 95% CI = 0.40-2.22). The inconsistency in the association between drinking tea and the risk of lung cancer reported in previous studies may in part be due to inadequate control of confounding of active smoking.     

Indoor air pollution and blood pressure in adult women living in rural China

Background: Almost half of the world’s population uses coal and biomass fuels for domestic energy. Limited evidence suggests that exposure to air pollutants from indoor biomass combustion may be associated with elevated blood pressure (BP).Objective: Our aim was to assess the relationship between air pollution exposure from indoor biomass combustion and BP in women in rural China.Methods: We measured 24-hr personal integrated gravimetric exposure to fine particles < 2.5 µm in aerodynamic diameter (PM_2.5) and systolic BP (SBP) and diastolic BP (DBP) in the winter and summer among 280 women ≥ 25 years of age living in rural households using biomass fuels in Yunnan, China. We investigated the association between PM_2.5 exposure and SBP and DBP using mixed-effects models with random intercepts to account for correlation among repeated measures.Results: Personal average 24-hr exposure to PM_2.5 ranged from 22 to 634 µg/m³ in winter and from 9 to 492 µg/m³ in summer. A 1-log-µg/m³ increase in PM_2.5 exposure was associated with 2.2 mm Hg higher SBP [95% confidence interval (CI), 0.8 to 3.7; p = 0.003] and 0.5 mm Hg higher DBP (95% CI, –0.4 to 1.3; p = 0.31) among all women; estimated effects varied by age group. Among women > 50 years of age, a 1-log-µg/m³ increase in PM_2.5 exposure was associated with 4.1 mm Hg higher SBP (95% CI, 1.5 to 6.6; p = 0.002) and 1.8 mm Hg higher DBP (95% CI, 0.4 to 3.2; p = 0.01). PM_2.5 exposure was positively associated with SBP among younger women, but the association was not statistically significant.Conclusion: PM_2.5 exposure from biomass combustion may be a risk factor for elevated BP and hence for cardiovascular events. Our findings should be corroborated in longitudinal studies.     

Impact of improved cookstoves on indoor air pollution and adverse health effects among Honduran women

Elevated indoor air pollution levels due to the burning of biomass in developing countries are well established. Few studies have quantitatively assessed air pollution levels of improved cookstoves and examined these measures in relation to health effects. We conducted a cross-sectional survey among 79 Honduran women cooking with traditional or improved cookstoves. Carbon monoxide and fine particulate matter (PM_2.5) levels were assessed via indoor and personal monitoring. Pulmonary function and respiratory symptoms were ascertained. Finger-stick blood spot samples were collected to measure C-reactive protein (CRP) concentrations. The use of improved stoves was associated with 63% lower levels of personal PM_2.5, 73% lower levels of indoor PM_2.5, and 87% lower levels of indoor carbon monoxide as compared to traditional stoves. Women using traditional stoves reported symptoms more frequently than those using improved stoves. There was no evidence of associations between cookstove type or air quality measures with lung function or CRP.     

Lung cancer and air pollution in southcentral Los Angeles County.

An increased rate of lung cancer has been consistently observed from 1968-1972 among males in southcentral Los Angeles. This excess risk occurs across several social classes and occupational categories. No differential excess of oral cavity, pancreatic, laryngeal and bladder cancer was observed in the same area, lessening the possibility that regional variations in smoking habits accounted for the excess lung cancer. Air sampling has indicated an excess of certain polynuclear aromatic hydrocarbons (PAH) in southcentral Los Angeles. There was a correlation between the geographic distribution of lung cancer cases and the general location of industries which have emitted these PAH. A case-controlled study of smoking, occupational and residential history in the southcentral area is underway.     

Respiratory and cardiovascular functions among smoking and nonsmoking girls from two regions with different air pollution degree

AIM: The aim of the present study was to analyze the respiratory and cardiovascular functions among smoking and nonsmoking girls attending two schools situated in regions with different levels of air pollution. The characteristic of air pollution is based on the data gathered by stations 1 and 2 belonging to the Uniform National System for Monitoring the Air Pollution in Bulgaria. The participants (n=108, 16.07+/-0.80 years) were separated in two groups: smokers (S1 - from school 1, S2 - from school 2) and nonsmokers (NS1 - from school 1, NS2 - from school 2). All of them performed pulmonary function testing and .cardiopulmonary exercise testing on a treadmill using our modification of the Balke protocol (Marinov et al., 2000). Reference values for European children, previously validated for the Bulgarian population, were used. RESULTS: There are no significant differences in mean levels of VC, IC, FEV1, MEF50 and MEF25 (as a percentage from the predicted value as well). The average level of the Tiffneau index is noticeably higher among nonsmokers from the two regions and is the lowest among smokers from the more polluted area, but a significant difference exists between S2 (88.7+/-5.9) and NS2 (92.6+/-4.7), p=0.047; T(L,CO)%pred: S1 (85.4+/-7.2) vs. S2 (86.7+/-8.2), p=0.048 and NS1 (88.3+/-8.2) vs. NS2 (92.8+/-14.5), p=0.037; V(E)%pred: S1 (127.5+/-9.6) vs. S2 (123.7+/-6.1), p=0.035; higher levels of total lung capacity (TLC%pred), S1 (107.3+/-9.2) vs. NS2 (104.3+/-9.1), p=0.009 and alveolar ventilation (VA), S1 (5.0+/-0.6) vs. NS2 (4.6+/-0.5), p=0.008. CONCLUSIONS: 1. The negative effects of the combined influence of tobacco smoking and air pollution on some respiratory and cardiovascular functions of adolescent girls are more pronounced than each influence alone. 2. The cardiopulmonary exercise test gives adequate information about the combined effect of air pollution and smoking and using it for preventive purposes is an advisable method.     

Lung cancer incidence and long-term exposure to air pollution from traffic

Background

Previous studies have shown associations between air pollution and risk for lung cancer.

Objective

We investigated whether traffic and the concentration of nitrogen oxides (NO_x) at the residence are associated with risk for lung cancer.

Methods

We identified 592 lung cancer cases in the Danish Cancer Registry among 52,970 members of the Diet, Cancer and Health cohort and traced residential addresses from 1 January 1971 in the Central Population Registry. We calculated the NO_x concentration at each address by dispersion models and calculated the time-weighted average concentration for all addresses for each person. We used Cox models to estimate incidence rate ratios (IRRs) after adjustment for smoking (status, duration, and intensity), environmental tobacco smoke, length of school attendance, occupation, and dietary intake of fruit.

Results

For the highest compared with the lowest quartile of NO_x concentration at the residence, we found an IRR for lung cancer of 1.30 [95% confidence interval (CI), 1.05–1.61], and the IRR for lung cancer in association with living within 50 m of a major road (> 10,000 vehicles/day) was 1.21 (95% CI, 0.95–1.55). The results showed tendencies of stronger associations among nonsmokers, among those with a relatively low fruit intake, and among those with a longer school attendance; only length of school attendance modified the effect significantly.

Conclusions

This study supports that risk for lung cancer is associated with different markers of air pollution from traffic near the residence.     

Asthmatic symptoms among pupils in relation to winter indoor and outdoor air pollution in schools in Taiyuan, China

BACKGROUND: There are few studies on associations between children's respiratory heath and air pollution in schools in China. The industrial development and increased traffic may affect the indoor exposure to air pollutants in school environment. Moreover, there is a need to study respiratory effects of environmental tobacco smoke (ETS) and emissions from new building materials in homes in China. OBJECTIVES: We studied the associations between pupils' asthmatic symptoms and indoor and outdoor air pollution in schools, as well as selected home exposures, in a coal-burning city in north China. METHODS: A questionnaire survey was administered to pupils (11-15 years of age) in 10 schools in urban Taiyuan, collecting data on respiratory health and selected home environmental factors. Indoor and outdoor school air pollutants and climate factors were measured in winter. RESULTS: A total of 1,993 pupils (90.2%) participated; 1.8% had cumulative asthma, 8.4% wheezing, 29.8% had daytime attacks of breathlessness. The indoor average concentrations of sulfur dioxide, nitrogen dioxide, ozone, and formaldehyde by class were 264.8, 39.4, 10.1, and 2.3 microg/m3, respectively. Outdoor levels were two to three times higher. Controlling for possible confounders, either wheeze or daytime or nocturnal attacks of breathlessness were positively associated with SO2, NO2, or formaldehyde. In addition, ETS and new furniture at home were risk factors for wheeze, daytime breathlessness, and respiratory infections. CONCLUSIONS: Indoor chemical air pollutants of mainly outdoor origin could be risk factors for pupils' respiratory symptoms at school, and home exposure to ETS and chemical emissions from new furniture could affect pupils' respiratory health.     

Indoor air pollution in rural China: cooking fuels, stoves, and health status

Solid fuels are a major source of indoor air pollution, but in less developed countries the short-term health effects of indoor air pollution are poorly understood. The authors conducted a large cross-sectional study of rural Chinese households to determine associations between individual health status and domestic cooking as a source of indoor air pollution. The study included measures of health status as well as measures of indoor air-pollution sources, such as solid cooking fuels and cooking stoves. Compared with other fuel types, coal was associated with a lower health status, including negative impacts on exhaled carbon monoxide level, forced vital capacity, lifetime prevalence of chronic obstructive pulmonary disease and asthma, and health care utilization. Decreasing household coal use, increasing use of improved stove technology, and increasing kitchen ventilation may decrease the short-term health effects of indoor air pollution.     

Passive smoking and lung cancer in nonsmoking women.

OBJECTIVES. The causes of lung cancer among nonsmokers are not clearly understood. To further evaluate the relation between passive smoke exposure and lung cancer in nonsmoking women, we conducted a population-based, case-control study. METHODS. Case patients (n = 618), identified through the Missouri Cancer Registry for the period 1986 through 1991, included 432 lifetime nonsmokers and 186 ex-smokers who had stopped at least 15 years before diagnosis or who had smoked for less than 1 pack-year. Control subjects (n = 1402) were selected from driver's license and Medicare files. RESULTS. No increased risk of lung cancer was associated with childhood passive smoke exposure. Adulthood analyses showed an increased lung cancer risk for lifetime nonsmokers with exposure of more than 40 pack-years from all household members (odds ratio [OR] = 1.3; 95% confidence interval [CI] = 1.0, 1.8) or from spouses only (OR = 1.3; 95% CI = 1.0, 1.7). When the time-weighted product of pack-years and average hours exposed per day was considered, a 30% excess risk was shown at the highest quartile of exposure among lifetime nonsmokers. CONCLUSIONS. Ours and other recent studies suggest a small but consistent increased risk of lung cancer from passive smoking. Comprehensive actions to limit smoking in public places and worksites are well-advised.     

Self-rated health among Mayan women participating in a randomised intervention trial reducing indoor air pollution in Guatemala

Background  

Indoor air pollution (IAP) from solid fuels is a serious health problem in low-income countries that can be alleviated using improved stoves. Although women are the principal users, few studies have investigated the self-assessed impact of the stoves on their health and lives.