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 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.     

Indoor air pollution and health of children in biomass fuel-using households of Bangladesh: comparison between urban and rural areas

Objectives  

Indoor air pollutants from biomass combustion pose a risk for respiratory diseases in children. It is plausible that distinct differences in the indoor air quality (IAQ) exist between urban and rural areas in developing countries since the living environment between these two areas are quite different. We have investigated possible differences in IAQ in urban and rural Dhaka, Bangladesh and the association of such differences with the incidence of respiratory and some non-respiratory symptoms in children of families using biomass fuel.     

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.     

Acute effects of urban air pollution on respiratory health of children with and without chronic respiratory symptoms

OBJECTIVES: To investigate to what extent different components of air pollution are associated with acute respiratory health effects in children with and without chronic respiratory symptoms. METHODS: During three consecutive winters starting in 1992-3, peak expiratory flow (PEF) and respiratory symptoms were registered daily in panels of children of 7-11 years old with and without symptoms, living in urban areas with high traffic intensity in The Netherlands. Simultaneously, panels of children living in non-urban areas were studied. Daily measurements of particles with aerodynamic diameter < 10 microns (PM10), black smoke (BS), sulphate, SO2, and NO2 were performed in both areas. RESULTS: The contrast in particle concentrations (PM10, BS, and sulphate) between urban and non-urban areas was small, but there was more contrast in the concentrations of SO2 and NO2. In children with symptoms from both areas, significant associations were found between PM10, BS, and sulphate concentrations and the prevalence of symptoms of the lower respiratory tract (LRS) and decrements in PEF. Particle concentrations were also associated with use of bronchodilators in the urban areas, but not in the non-urban areas. After stratification by use of medication, stronger associations were found in children who used medication than in children who did not use medication. The magnitude of the estimated effects was in the order of a twofold increase in the use of bronchodilators, a 50% increase in LRS, and an 80% increase in decrements in PEF for a 100 micrograms/m3 increase in the 5 day mean PM10 concentration. In children without symptoms, significant associations were found between concentrations of PM10 and BS and decrements in PEF in both areas, but these associations were smaller than those for children with symptoms. No associations with respiratory symptoms were found. CONCLUSIONS: The results suggest that children with symptoms are more susceptible to the effects of particulate air pollution than children without symptoms, and that use of medication for asthma does not prevent the adverse effects of particulate air pollution in children with symptoms.

 

     

Indoor air pollution exposure and lower respiratory infections in young Gambian children

In a rural population-based cohort study of approximately 500 Gambian children under five years old followed for one year, incidence of acute lower respiratory infections (ALR) was related to various risk factors including parental smoking and regular carriage on the mother's back while cooking, a proxy measure for exposure to smoke from cooking fires. Two statistical analyses using a 'child-weeks at risk' approach were carried out, including and excluding multiple disease episodes in the same child. Weekly surveillance for ALRI found 75 episodes in 62 children. Stratified analyses using both approaches suggested father's smoking, and, for girls only, carriage on the mother's back while cooking and being part of a polygamous family were the main risk factors associated with infection: when multiple episodes occurring in the same child were excluded, not having a health card was an additional risk factor in children over a year old. Multiple logistic regression modelling of data from both approaches, including each of these risk factors and sex, age, village and season, suggested father's smoking, carriage on the mother's back while cooking and being part of a polygamous family increase risk of ALRI, the latter two for girls only. The analysis excluding multiple episodes in the same child also suggested that not having a health card is a risk factor for children aged 1-5 years. The difficulties in interpreting these findings are discussed.     

Ambient air pollution and respiratory health effects in mail carriers

Mail carriers represent an occupational group suffering from respiratory symptoms and lung function impairment. Although environmental conditions may play role, information on the effects of air pollution exposure in this population is lacking.The present study was conducted in Athens, Greece, in order to investigate the adverse effects of long-term air pollution exposure on respiratory outcomes in mail carriers.A total of 226 mail carriers and 73 office employees were enroled. Information on respiratory symptoms, medical, occupational, residential and smoking history was obtained through a questionnaire. Flow-volume curves were performed in the workplace using a portable spirometer. Individualised personal exposure assessment has been applied based on long-term residential and occupational subject history linked with geographical air pollution distribution. Furthermore, personal measurements were obtained for forty-one mail carriers using NO₂ and O₃ passive samplers, assuming that current air pollution exposure is sufficiently representative of long-term, previous exposure to make a plausible link with current health status.The analysis based on exposures estimated on the basis of residential and work addresses showed that the most exposed to PM₁₀ postal workers have rhinitis at a higher rate (OR=1.67, 95% CI: 1.01-2.75). In mail carriers there is indication that those exposed to higher concentrations of Ο₃ or PM₁₀ have a greater possibility to present rhinitis (OR=1.63, 95% CI: 0.93-2.88 and OR=1.70, 95% CI: 0.96-3.03, respectively). The effect of O₃ on rhinitis became even more apparent in the analysis based on exposures assessed by personal measurements (OR=6.74, 95% CI: 1.24-36.55). Exposure to NO₂ was significantly associated with decrements in lung function. For office employees the exposure to air pollutants was not associated to any adverse respiratory outcome.Our findings suggest that air pollution is a contributing factor for the occurrence of rhinitis and lung function impairment in mail carriers.     

Indoor air quality and acute lower respiratory infection in Indian urban slums.

The present prospective study was conducted at two urban slums of Delhi, Kusumpur Pahari and Kathputly Colony, in the peak winter season from November 1994 through February 1995. We studied 642 infants to determine the incidence of acute lower respiratory infection (ALRI) and its relationship to indoor air pollution due to fuel used for cooking (wood or kerosene). In Kusumpur Pahari, there were 317 children (142 wood and 175 kerosene), including 64 controls and 78 cases of ALRI in the wood fuel group and 81 controls and 94 ALRI cases in the kerosene group (p > 0.05). Out of 316 children in Kathputly Colony (174 wood and 142 kerosene), there were 33 and 45 ALRI cases in the wood and kerosene groups, respectively (p < 0.05). Controls were children without ALRI and were used as controls in different groups. The demographic data and risk factors, namely, nutritional and immunization status, were comparable in ALRI cases and controls in both study areas. Pneumonia was the most common ailment in all the groups. Bronchiolitis was reported in 22.5% of the wood group and 27.1% of the kerosene group in Kathputly Colony versus 13.7% in the wood group and 12.1% in the kerosene group in Kusumpur Colony. Only one case of croup was reported from Kusumpur Pahari among wood users. The duration of illness was longer in the Kusumpur Pahari due to poor compliance, feeding, and child rearing habits. In conclusion, a higher incidence of ALRI was reported in kerosene users in Kathputly Colony, a high pollution area; however, the reasons for the differences observed need further elucidation.     

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)     

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…     

Effect of stove intervention on household air pollution and the respiratory health of women and children in rural Nigeria

Domestic cooking with biomass fuels exposes women and children to pollutants that impair health. The objective of the study was to investigate the extent of household air pollution from biomass fuels and the effectiveness of stove intervention to improve indoor air quality, exposure-related health problems, and lung function. We conducted a community-based pilot study in three rural communities in southwest Nigeria. Indoor levels of particulate matter (PM_2.5) and carbon monoxide (CO) were measured, and exposure-related health complaints were assessed in 59 households that used firewood exclusively for cooking. Fifty-nine mother–child pairs from these households were evaluated pre-intervention and 1 year after distribution and monitored use of low-emission stoves. Mean age (± SD; years) of mothers and children were 43.0?±?11.7 and 13.0?±?2.5, respectively. Median indoor PM_2.5 level was 1414.4 μg/m³ [interquartile range (IQR) 831.2–3437.0] pre-intervention and was significantly reduced to 130.3 μg/m³ (IQR 49.6–277.1; p?<?0.0001) post-intervention. Similarly, the median CO level was reduced from 170.3 ppm (IQR 116.3–236.2) to 14.0 ppm (IQR 7.0–21.0; p?<?0.0001). There were also significant reductions in frequency of respiratory symptoms (dry cough, chest tightness, difficult breathing, and runny nose) in mothers and children. Over 25 % of mothers and children had moderate airway obstruction on spirometry pre-intervention that did not improve 1 year after intervention period. Cooking with firewood causes household air pollution and compromised lung health. Introduction of low-emission stoves was effective at improving indoor air quality and reducing exposure-related symptoms.     

Effect of air pollution and racism on ethnic differences in respiratory health among adolescents living in an urban environment

Recent studies suggest that stress can amplify the harm of air pollution. We examined whether experience of racism and exposure to particulate matter with an aerodynamic diameter of less than 2.5 µm and 10 µm (PM_2.5 and PM₁₀) had a synergistic influence on ethnic differences in asthma and lung function across adolescence. Analyses using multilevel models showed lower forced expiratory volume (FEV₁), forced vital capacity (FVC) and lower rates of asthma among some ethnic minorities compared to Whites, but higher exposure to PM_2.5, PM₁₀ and racism. Racism appeared to amplify the relationship between asthma and air pollution for all ethnic groups, but did not explain ethnic differences in respiratory health.     

Indoor air quality in urban and rural kindergartens: short-term studies in Silesia,Poland

More than 80% of people living in urban areas who monitor air pollution are exposed to air quality levels that exceed limits defined by the World Health Organization (WHO). Although all regions of the world are affected, populations in low-income cities are the most impacted. According to average annual levels of fine particulate matter (PM2.5, ambient particles with aerodynamic diameter of 2.5 μm or less) presented in the urban air quality database issued by WHO in 2016, as many as 33 Polish cities are among the 50 most polluted cities in the European Union (EU), with Silesian cities topping the list. The aim of this study was to characterize the indoor air quality in Silesian kindergartens based on the concentrations of gaseous compounds (SO₂, NO₂), PM2.5, and the sum of 15 PM2.5-bound polycyclic aromatic hydrocarbons (PAHs), including PM2.5-bound benzo(a)pyrene (BaP), as well as the mutagenic activity of PM2.5 organic extracts in Salmonella assay (strains: TA98, YG1024). The assessment of the indoor air quality was performed taking into consideration the pollution of the atmospheric air (outdoor). I/O ratios (indoor/outdoor concentration) for each investigated parameter were also calculated. Twenty-four-hour samples of PM2.5, SO₂, and NO₂ were collected during spring in two sites in southern Poland (Silesia), representing urban and rural areas. Indoor samples were taken in naturally ventilated kindergartens. At the same time, in the vicinity of the kindergarten buildings, the collection of outdoor samples of PM2.5, SO₂, and NO₂ was carried out. The content of BaP and the sum of 15 studied PAHs was determined in each 24-h sample of PM2.5 (indoor and outdoor). In the urban site, statistically lower concentrations of SO₂ and NO₂ were detected indoors compared to outdoors, whereas in the rural site, such a relationship was observed only for NO₂. No statistically significant differences in the concentrations of PM2.5, PM2.5-bound BaP, and Σ15 PAHs in kindergartens (indoor) versus atmospheric (outdoor) air in the two studied areas were identified. Mutagenic effect of indoor PM2.5 samples was twice as low as in outdoor samples. The I/O ratios indicated that all studied air pollutants in the urban kindergarten originated from the ambient air. In the rural site concentrations of SO₂, PM2.5 and BaP in the kindergarten were influenced by internal sources (gas and coal stoves).     

Indoor air pollution and acute lower respiratory infections in the first two years of life

The relationship between outdoor air pollution and acute respiratory infections (ARI) was previously documented. There are recent indications for connection between indoor air pollution and ARI in infants and young children. The aim of this study was to identify the relationship of indoor air pollutants to acute lower respiratory infection (ALRI) in children (< 2 years). The indoor air pollutants concentrations were measured in the homes of the sample. The sample consisted of 115 children (< 2 years) representing the control group (24), ALRI but no pneumonia (24), pneumonia (30), severe pneumonia or very severe disease (37). Air sampling was performed to measure the concentration of total suspended particulates (TSP), SO2 and CO. These pollutants were found in higher concentrations in cases' homes (52.46 +/- 19.68 microg/m3, 298.15 +/- 669.37 microg/m3, and 1.92 +/- 3.60 ppm) than in controls' homes (31.92 +/- 8.76 microg/m3, not detected, and 0.33 +/- 1.63 ppm respectively). Whereas SO2 was detected only in houses using kerosene, TSP and CO were detected with the different types of cooking fuels. Their mean concentrations were highest for biomass (88.86 +/- 13.30 microg/m3 and 9.29 +/- 2.50 ppm) and lowest for gas (40.78 +/- 15.25 microg/m3 and 0.76 +/- 2.19 ppm). Measures to improve indoor air quality are highly required.     

Indoor air pollution in developing countries: a major environmental and public health challenge

Around 50% of people, almost all in developing countries, rely on coal and biomass in the form of wood, dung and crop residues for domestic energy. These materials are typically burnt in simple stoves with very incomplete combustion. Consequently, women and young children are exposed to high levels of indoor air pollution every day. There is consistent evidence that indoor air pollution increases the risk of chronic obstructive pulmonary disease and of acute respiratory infections in childhood, the most important cause of death among children under 5 years of age in developing countries. Evidence also exists of associations with low birth weight, increased infant and perinatal mortality, pulmonary tuberculosis, nasopharyngeal and laryngeal cancer, cataract, and, specifically in respect of the use of coal, with lung cancer. Conflicting evidence exists with regard to asthma. All studies are observational and very few have measured exposure directly, while a substantial proportion have not dealt with confounding. As a result, risk estimates are poorly quantified and may be biased. Exposure to indoor air pollution may be responsible for nearly 2 million excess deaths in developing countries and for some 4% of the global burden of disease. Indoor air pollution is a major global public health threat requiring greatly increased efforts in the areas of research and policy-making. Research on its health effects should be strengthened, particularly in relation to tuberculosis and acute lower respiratory infections. A more systematic approach to the development and evaluation of interventions is desirable, with clearer recognition of the interrelationships between poverty and dependence on polluting fuels.     

Assessment of air pollution health effects on respiratory organs]

During the past three decades, industrial expansion in Japan has been remarkable, resulting in a numerous number of chemical substances got synthesized. Unfortunately, our living environment has concomitantly been polluted with such substances released through industrial activities and our daily lives, and health injuries have occasionally occurred in the human population. Although the critical conditions in the 1960s were overcome by the countermeasures we took, the potential for environmental pollution still remains. In the present social and economical situation, the management of environmental pollutants should be decided depending upon more quantitative and predictive evaluation of their health effects. In this paper the author tries to evaluate the relation of air pollution to chronic bronchitis, bronchial asthma and pulmonary cancer from a quantitative point of view.