Cooking fuel type, household ventilation, and the risk of acute lower respiratory illness in urban Bangladeshi children: a longitudinal study

Acute lower respiratory illnesses (ALRI) are the leading cause of death among children <5 years. Studies have found that biomass cooking fuels are an important risk factor for ALRI. However, few studies have evaluated the influence of natural household ventilation indicators on ALRI. The purpose of this study was to assess the association between cooking fuel, natural household ventilation, and ALRI. During October 17, 2004-September 30, 2005, children <5 years living in a low-income neighborhood of Dhaka, Bangladesh, were assessed weekly for ALRI and surveyed quarterly about biomass fuel use, electric fan ownership, and natural household ventilation (windows, ventilation grates, and presence of a gap between the wall and ceiling). Bivariate and multivariate analyses were performed using generalized estimating equations. Six thousand and seventy-nine children <5 years enrolled during the study period (99% participation) experienced 1291 ALRI. In the multivariate model, ≥2 windows [OR = 0.75, 95% CI = (0.58, 0.96)], ventilation grates [OR = 0.80, 95% CI = (0.65, 0.98)], and not owning an electric fan [OR = 1.50, 95% CI = (1.21, 1.88)] were associated with ALRI; gap presence and using biomass fuels were not associated with ALRI. Structural factors that might improve household air circulation and exchange were associated with decreased ALRI risk. Improved natural ventilation might reduce ALRI among children in low-income families. PRACTICAL IMPLICATIONS: The World Health Organization has stated that controlling pneumonia is a priority for achieving the fourth Millennium Development Goal, which calls for a two-third reduction in mortality of children <5 years old compared to the 1990 baseline. Our study represents an important finding of a modifiable risk factor that might decrease the burden of respiratory illness among children living in Bangladesh and other low-income settings similar to our study site. We found that the existence of at least two windows in the child's sleeping room was associated with a 25% decreased ALRI risk. Increasing available natural ventilation within the household in similar settings has the potential to reduce childhood mortality because of acute lower respiratory illnesses.     

Onset of mucosal, dermal, and general symptoms in relation to biomarkers and exposures in the dwelling: a cohort study from 1992 to 2002

We examined the associations between biomarkers of allergy and inflammation, indoor environment in dwellings, and incidence and remission of symptoms included in the sick building syndrome (SBS) and changes in the home environment of 452 adults who were followed from 1992 to 2002 within the Uppsala part of the European Community Respiratory Health Survey (ECRHS). The 10-year incidence (onset) of general, mucosal, and dermal symptoms was 8.5%, 12.7%, and 6.8%, respectively. Dampness or indoor molds at baseline was a predictor of incidence of general (relative risk [RR] = 1.98), mucosal (RR = 2.28), and dermal symptoms (RR = 1.91). Women had higher incidence of general (RR = 1.74) and mucosal symptoms (RR = 1.71). Indoor painting increased the incidence of general symptoms (RR = 1.62). Bronchial responsiveness (BR), eosinophil counts in blood, total IgE and eosinophilic cationic protein (ECP) in serum at baseline were predictors of incidence of SBS. At follow-up, BR, total IgE, and C-reactive protein (CRP ) were associated with increased incidence of SBS. Moreover, subjects with doctor-diagnosed asthma at baseline had a higher incidence of general (RR = 1.65) and mucosal symptoms (RR = 1.97). In conclusion, female gender, dampness or indoor molds, indoor painting, and biomarkers of allergy and inflammation were associated with a higher incidence of SBS symptoms, in particular mucosal symptoms. PRACTICAL IMPLICATIONS: The focus in Sweden on indoor environment issues over the last few decades has resulted in improvements in dwellings, and reduced tobacco smoking, which could be beneficial for public health. Reducing dampness and molds in the dwelling place is another important way of reducing occurrence of SBS symptoms in the general adult population. The association between the incidence of SBS symptoms and clinical biomarkers of allergy and inflammation suggests a common etiology between inflammatory diseases, including asthma, rhinitis, and SBS. Lastly, good agreement between self-reported and clinically diagnosed atopy indicates that questionnaire data on atopy can be used in epidemiological studies.     

Transit-oriented development in a high-density city: Identifying its association with transit ridership in Seoul, Korea

This study determines whether transit-oriented development (TOD) planning factors identified from western case studies can be applied to the city of Seoul, Korea, which is characteristic of dense development. The authors illustrate the distributional patterns and characteristics of planning factors such as transit supply service, land use, street network and urban design at each rail station area. To identify effects of TOD planning factors upon the transit ridership at the targeted 214 rail station areas in Seoul, the study develops multiple regression models for transit ridership, which are differentiated at the levels of time of day, day of the week, and transit mode at the respective rail station areas. The analysis results suggest that TOD planning factors can have a significant positive impact in forming a transit-oriented city. They also indicate that some TOD planning factors, compared to low-density cities in Western countries, need to be carefully applied towards Seoul in order to achieve the objective of regenerating a transit-oriented city. In summary, rather than focusing mainly on increasing development density, it is necessary to concentrate more on such strategies as strengthening the transit service network, increasing the land-use mix index, and restructuring the street networks and urban design to be more pedestrian friendly around rail stations.     

Dampness in dorm rooms and its associations with allergy and airways infections among college students in China: a cross‐sectional study

Abstract Abstract A cross‐sectional study was carried out at Tianjin University campus, China, from February 21 to June 10, 2006, to survey the association between dampness in dorms, and allergy and airways infections among college students. The health and dampness conditions were self‐reported by 3436 students living in 1511 dorm rooms located in 13 buildings on the campus. The buildings were selected according to their positions, construction periods and occupant densities. The symptoms involved wheezing, dry cough during night, rhinitis, eczema, cold/flu, ear inflammation, pneumonia and tuberculosis. The indoor moisture signs were mould/damp spots on walls, ceilings and floors; suspected or ever happened water damage; condensation on windowpane in winter and odours perceived by subjects themselves. There was a significant positive association between condensation and dry cough. Eczema was often reported in rooms with moisture problem. Dampness was a significant risk factor for common cold.     

Bioaugmentation with the nicotine-degrading bacterium Pseudomonas sp. HF-1 in a sequencing batch reactor treating tobacco wastewater: Degradation study and analysis of its mechanisms

The highly effective nicotine-degrading bacterium Pseudomonas sp. HF-1 was augmented in an SBR system that is used to treat tobacco wastewater. Compared to the non-bioaugmented (non-BA) system, the bioaugmented (BA) system exhibited considerably stronger pollution disposal abilities, with 100% nicotine degradation and more than 84% chemical oxygen demand (COD) removal within 12 h. Nicotine degradation had a significant effect on COD removal in SBRs (r = 0.928, p < 0.01). The mechanisms of bioaugmentation were systematically investigated using a combination of polymerase chain reaction and denaturing gradient gel electrophoresis (PCR-DGGE) and a toxicity assay (protein carbonyl (PC) and DNA-protein crosslinking (DPC)). DGGE fingerprint profiles showed that the number of bands and the Shannon-Wiener index decreased at a nicotine load of 250 mg/L compared to a 40-130 mg/L nicotine load in the non-BA system. However, a stepwise increase in the Shannon-Wiener index was found during all periods in the BA system. A comparison of sequences excised from DGGE gels demonstrated significant differences in the dominant microbial species between the two SBRs. This result suggested that bioaugmentation of strain HF-1 could select cooperators for treating complicated tobacco wastewater. The PC content and the DPC coefficient increased significantly at levels higher than 80 mg/L in the non-BA system; nevertheless, no increase was observed in the BA system during the stepwise nicotine load. This indicated that bioaugmentation of strain HF-1 resulted in the maintenance of high treatment activity by minimizing the nicotine toxicity for other microbes in the BA system. In conclusion, the rapid nicotine degradation of strain HF-1 performed a vital function in SBR by influencing the microbial community structure, dynamics and activity of the activated sludge system.