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.     

Indoor air pollution by polynuclear hydrocarbons from tobacco smoke

Summary An orientation study on concentration levels of PAH in a closed space was carried out with concern about ventilation and quantity of cigarettes smoked. Emission factors of PAH and their methyl derivatives in the main and side-streams of light and heavy cigarettes were determined.

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Innenluftverunreinigung durch polyzyklische aromatische Kohlenwasserstoffe (PAH) im tabakrauch

Zusammenfassung Eine Orientierungsstudie über die PAH-Gehalte in einem geschlossenen Raum wurde in Hinblick auf Ventilation und Anzahl gerauchter Zigaretten durchgeführt. Emissionsfaktoren der PAH und derer Methylhomologen im Haupt- und Nebenrauch wurde bei leichten und starken Zigaretten bestimmt.

     

我国室内空气污染

20世纪中期 ,人们已认识到室内空气污染有时比室外更严重。近 2 0多年来 ,室内空气质量的卫生问题已经成为国内外学者极为关注的环境卫生问题之一。因为室内环境是人们接触最密切的外环境之一 ;室内污染物的来源和种类越来越多。随着经济、生活和生产水平的不断提高 ,室内使用的化学品和建筑材料等的种类和数量比以往明显增多 ;建筑物密闭程度增加 ,使室内污染物不易排出 ,室外新鲜空气也不能正常进入 ,增加了室内人群与污染物的接触机会。1　室内污染物的主要来源和种类1.1　燃料燃烧煤、煤气、液化石油气、天然气等燃烧时会排出颗粒物、一…     

Indoor air pollution in developing countries

Of the four principal categories of indoor pollution (combustion products, chemicals, radon and biologicals), research in developing countries has focused on combustion-generated pollutants, and principally those from solid-fuel-fired cooking and heating stoves. Such stoves are used in more than half the world's households and have been shown in many locations to produce high indoor concentrations of particulates, carbon monoxide and other combustion-related pollutants. Although the proportion of all such household stoves that are used in poorly ventilated situations is uncertain, the total population exposed to excessive concentrations is potentially high, probably several hundred million. A number of studies were carried out in the 1980s to discover the health effects of such stove exposures. The majority of such studies were done in South Asia in homes burning biomass fuels or in China with coal-burning homes, although a sprinkling of studies examining biomass-burning have been done in Oceania, Latin America and Africa. Of the health effects that might be expected from such exposures, little, if any, work seems to have been done on low birthweight and eye problems, although there are anecdotal accounts making the connection. Decreased lung function has been noted in Nepali women reporting more time spent near the stove as it has for Chinese women using coal stoves as compared to those using gas stoves. Respiratory distress symptoms have been associated with use of smoky fuels in West India, Ladakh and in several Chinese studies among different age groups, some with large population samples. Acute respiratory infection in children, one of the chief causes of infant and childhood mortality, has been associated with Nepali household-smoke exposures. Studies of chronic disease endpoints are difficult because of the need to construct exposure histories over long periods. Nevertheless, chronic obstructive lung disease has been associated with the daily time spent near the stove for Nepali women and found to be elevated among coal-stove users compared to gas-stove users in Shanghai. In contrast to early reports, there seems to be little or no risk of nasopharyngeal cancer from cookstove smoke. Several studies in China, however, have found smoke to be a strong risk factor for lung cancer among non-smoking women. In addition, severe fluorosis has been observed in several parts of China where coal fluoride levels are high.(ABSTRACT TRUNCATED AT 250 WORDS)     

Indoor air pollution from unprocessed solid fuels in developing countries

Approximately half of the world's population relies on biomass (primarily wood and agricultural residues) or coal fuels (collectively termed solid fuels) for heating, lighting, and cooking. The incomplete combustion of such materials releases byproducts with well-known adverse health effects, hence increasing the risk of many diseases and death. Among these conditions are acute respiratory infections, chronic obstructive pulmonary disease, heart disease, stroke, lung cancer, cataracts and blindness, tuberculosis, asthma, and adverse pregnancy outcomes. The International Agency for Research on Cancer has classified the indoor combustion of coal emissions as Group 1, a known carcinogen to humans. Indoor air pollution exposure is greatest in individuals who live in rural developing countries. Interventions have been limited and show only mixed results. To reduce the morbidity and mortality from indoor air pollution, countermeasures have to be developed that are practical, efficient, sustainable, and economical with involvement from the government, the commercial sector, and individuals. This review focuses on the contribution of solid fuels to indoor air pollution.     

Winter air pollution and infant bronchiolitis in Paris

Respiratory syncytial virus (RSV) is one of the most common respiratory pathogens in infants and young children. It is not known why some previously healthy infants, when in contact with RSV, develop bronchiolitis whereas others have only mild symptoms. Our study aimed to evaluate the possible association between emergency hospital visits for bronchiolitis and air pollution in the Paris region during four winter seasons. We included children under the age of 3 years who attended emergency room services for bronchiolitis (following standardized definition) during the period 1997-2001. Two series of data from 34 hospitals, the daily number of emergency hospital consultations (n=50857) and the daily number of hospitalizations (n=16588) for bronchiolitis, were analyzed using alternative statistical methods; these were the generalized additive model (GAM) and case-crossover models. After adjustments for public holidays, holidays and meteorological variables the case-crossover model showed that PM10, BS, SO2 and NO2 were positively associated with both consultations and hospitalizations. GAM models, adjusting for long-term trend, seasonality, holiday, public holiday, weekday and meteorological variables, gave similar results for SO2 and PM10. This study shows that air pollution may act as a trigger for the occurrence of acute severe bronchiolitis cases.     

Indoor climate, air pollution, and human comfort.

The term sick building syndrome (SBS) is frequently used to describe a set of symptoms often reported by occupants of certain buildings. The symptoms are supposed to be direct or indirect consequences of an inadequate indoor climate. Typically, a majority of the occupants in these buildings complain, and the most frequent complaint is irritation of eyes, nose, and throat. Many different factors are known to be potential agents for the symptoms and no definitive causality has been identified yet. In consequence authors of publications on indoor air quality have been using the SBS term in different ways. A review of literature indicates that in supposed "sick buildings" only the prevalence of irritation of mucosal membranes and headaches seems to differ significantly from the prevalence in buildings considered to have a normal indoor climate. Volatile organic compounds (VOC) are known to have a potency to cause symptoms like those included in SBS. A dose-response relation for sensory reactions and mucosal irritation caused by volatile organic air pollutants is discussed, and a tentative guideline at 3 mg/m3 (about 0.9 PPM toluene equivalent) for the total volatile organic compounds (TVOC) is suggested for the nonindustrial indoor climates.     

Indoor air pollution and pulmonary function growth in preadolescent children

Results are reported from a study of the association between exposure to sidestream cigarette smoke or gas stove emissions and pulmonary function level and growth rate of 7,834 children seen at 2-5 annual visits between the ages of 6-10 years. Children whose mothers smoked one pack of cigarettes per day had levels of forced expiratory volume in one second (FEV1) at age eight that were 0.81% lower than children of nonsmoking mothers (p less than 0.0001), and FEV1 growth rates approximately 0.17% per year lower (p = 0.05). For a child of age eight with an FEV1 of 1.62 liters, this corresponds to a deficit in rate of change of FEV1 of approximately 3 ml/annum and a deficit of 13 ml at age eight. Children whose mothers smoked one pack per day had levels of forced vital capacity (FVC) at age eight that were 0.33% higher than children of nonsmokers (p = 0.12); however, their growth rates of FVC were 0.17% per year lower (p = 0.04). Because few mothers changed their smoking habits during the course of the study, it was not possible to determine whether the difference in rate of growth was due to current exposure or to an effect of prenatal and early childhood exposure on the course of development. The magnitude of the effect on FEV1 is consistent with deficits in FEV1 of up to 3% in early adult life due to childhood exposure to sidestream cigarette smoke. The importance of this relatively small effect will be evaluated further through follow-up of these children as they are exposed to other risk factors such as personal active smoking. The data provide some evidence for an association between gas stove exposure and pulmonary function level, especially at younger ages, but no evidence for an effect of gas stove exposure on growth rate.     

Indoor air pollution and respiratory health in urban and rural China

During the summer of 1999, information about respiratory health outcomes and relevant covariates was collected from 3,709 Chinese adults in Beijing, Anqing City, and rural communities in Anqing Prefecture. Indoor PM10 and SO2 were measured in a random sample of selected households. Using logistic regression and controlling for important covariates (excluding PM10 and SO2) and familial intraclass correlation, highly significant differences were found between study areas in the prevalences of chronic cough, chronic phlegm, wheeze, and shortness of breath, but not physician-diagnosed asthma. Generally, the lowest prevalence of respiratory symptoms was observed in Anqing City, a higher prevalence in rural Anqing, and the highest prevalence in Beijing. Median indoor concentrations of PM10 were similar in Anqing City (239 microg/m3) and rural Anqing (248 microg/m3), but much higher in Beijing (557 microg/m3). Median indoor concentrations of SO2 were similar in all three areas (Beijing: 14 microg/m3, Anqing City: 25 microg/m3, rural Anqing: 20 microg/m3).     

室内空气污染与儿童哮喘关系的研究现状

哮喘是当今世界最常见的呼吸道慢性炎症性疾病，也是全球范围内严重威胁儿童健康的一种主要慢性疾病。据估计，全球已有3亿哮喘患者，约有1．5亿哮喘儿童患者，其发病率和死亡率仍在不断上升，并以每10年20％-50％的比率上升。世界卫生组织研究报告中指出，全世界每年有10万人因为室内空气污染而死于哮喘病，而其中35％为儿童。     

Indoor air pollution from biomass fuels: a major health hazard in developing countries

Background

Nearly 3 billion people live without electricity today. This energy poverty means that they have to resort to biomass fuels for their household energy needs. When burned, these fuels release a mixture of toxic chemicals in their smoke, which is often over twenty times greater than World Health Organization (WHO) and Environmental Protection Agency recommended guideline limits.

Aim

This review details factors that contribute to indoor air pollution, its effects on health, and discusses corrective measures to consider when planning intervention strategies to stem the high morbidity and mortality trend.

Methods

The term developing countries is defined using the 2008 United Nations Conferences on Trade and Development Handbook. PubMed, Google Scholar and Science Direct databases from 1990 to 2011 were searched using the key terms: indoor air pollution, biomass fuel, particulate matter, health risks, and developing countries. Bibliographies of all relevant articles were also screened to find further eligible articles. Inclusion criteria were peer-reviewed articles and technical reports from global health organizations such as the WHO and United Nations Development Program. Exclusion criteria were articles focused on modern energy, developed countries, and non-English publications.

Results

The review discusses the extent of indoor air pollution related to use of biomass for cooking and assesses its impact on various health and social problems, including lung diseases, adverse pregnancy outcomes and human development, especially in vulnerable populations. It also offers strategies to mitigate problems related to indoor air pollution.

Conclusions

Biomass fuel is a major cause of indoor air pollution and is a significant health hazard in developing countries. A thorough understanding of the connection between choice of fuel for household needs and health impact of long-term exposure to pollutants from smoke generated during use of biomass for cooking is required so that appropriate intervention strategies and policies can be established to protect vulnerable populations.     

Indoor air pollution by smoke constituents—A survey

A review of the literature on the present state of knowledge about the topic "indoor air pollution by smoke constituents" has been made. While consideration is given to standard bibliographic works and more recent reviews, an evaluation of the results of field studies and experimental investigations carried out under realistic conditions is also made. The selection of the tobacco smoke constituents discussed here was based on environmental and toxicological aspects. The following substances are considered in detail: carbon monoxide, nitrogen oxides, formaldehyde, acrolein, ammonia, phenol, hydrogen cyanide, sulfur dioxide, cadmium, nickel, nicotine, some volatile nitrosamines, polycyclic aromatic hydrocarbons, and respirable particulates. The smoke constituent concentrations in the literature are presented in tables. The results are evaluated and discussed with respect to the maximum allowable concentrations presently valid in the Federal Republic of Germany.     

Indoor air pollution from biomass fuels and respiratory health of the exposed population in Nepalese households

A cross-sectional assessment of indoor air quality in Nepal and its health effects revealed that solid biomass fuels (animal dung, crop residue, and wood) were the main sources of indoor air pollution affecting health. The average smoke level (PM10) in kitchens using biomass fuels was about three times higher than that in those using cleaner fuels (kerosene, LPG, and biogas). Respondents in 98 randomly selected households included 168 who cooked daily meals, of whom 94% were disadvantaged women. Biomass smoke caused significantly more respiratory disorders than did cleaner fuels. Categorized data analysis demonstrated significant associations between biomass smoke pollution and respiratory symptoms such as cough; phlegm; breathlessness; wheezing; and chronic respiratory diseases such as COPD and asthma. The prevalences of respiratory illnesses and symptoms were considerably higher in those living in mud and brick houses compared with concrete houses. Prevalences were also higher in those living on hills and in rural areas compared with flatland and urban areas.