Vijayalakshmi Thanasekaraan

Air pollution from household solid fuel combustion in India: an overview of exposure and health related information to inform health research priorities

Environmental and occupational risk factors contribute to nearly 40% of the national burden of disease in India, with air pollution in the indoor and outdoor environment ranking amongst leading risk factors. It is now recognized that the health burden from air pollution exposures that primarily occur in the rural indoors, from pollutants released during the incomplete combustion of solid fuels in households, may rival or even exceed the burden attributable to urban outdoor exposures. Few environmental epidemiological efforts have been devoted to this setting, however. We provide an overview of important available information on exposures and health effects related to household solid fuel use in India, with a view to inform health research priorities for household air pollution and facilitate being able to address air pollution within an integrated rural–urban framework in the future.

Prevalence of chronic obstructive pulmonary disease in rural women of Tamilnadu: implications for refining disease burden assessments attributable to household biomass combustion

Background Chronic obstructive1 1This paper was orally presented in the Annual conference International Society of Environmental Epidemiology held in Pasadena in 2008. pulmonary disease (COPD) is the 13th leading cause of burden of disease worldwide and is expected to become 5th by 2020. Biomass fuel combustion significantly contributes to COPD, although smoking is recognized as the most important risk factor. Rural women in developing countries bear the largest share of this burden resulting from chronic exposures to biomass fuel smoke. Although there is considerable strength of evidence for the association between COPD and biomass smoke exposure, limited information is available on the background prevalence of COPD in these populations. Objective This study was conducted to estimate the prevalence of COPD and its associated factors among non-smoking rural women in Tiruvallur district of Tamilnadu in Southern India. Design This cross-sectional study was conducted among 900 non-smoking women aged above 30 years, from 45 rural villages of Tiruvallur district of Tamilnadu in Southern India in the period between January and May 2007. COPD assessments were done using a combination of clinical examination and spirometry. Logistic regression analysis was performed to examine the association between COPD and use of biomass for cooking. R software was used for statistical analysis. Results The overall prevalence of COPD in this study was found to be 2.44% (95% CI: 1.43–3.45). COPD prevalence was higher in biomass fuel users than the clean fuel users 2.5 vs. 2%, (OR: 1.24; 95% CI: 0.36–6.64) and it was two times higher (3%) in women who spend >2 hours/day in the kitchen involved in cooking. Use of solid fuel was associated with higher risk for COPD, although no statistically significant results were obtained in this study. Conclusion The estimates generated in this study will contribute significantly to the growing database of available information on COPD prevalence in rural women. Moreover, with concomitant indoor air pollution measurements, it may be possible to increase the resolution of the association between biomass use and COPD prevalence and refine available attributable burden of disease estimates.

Evaluation of mucociliary clearance among women using biomass and clean fuel in a periurban area of Chennai: A preliminary study.

Background: Nasal mucociliary clearance (NMC) plays a crucial role in the defense of the airways against inhaled substances and is affected by various factors. The effect of particulate matter on NMC in women using biomass fuel has not been well studied. Aim: This cross-sectional study was conducted to assess the NMC time in biomass fuel users and compare it with that of clean fuel users. Materials and Methods: NMC time and Peak Expiratory Flow Rate (PEFR) were determined in women of age ranging from 18 to 45 years using biomass fuel (n=30) and clean fuel (n=30). The time taken to perceive the sweet taste, following placement of saccharin 1 cm behind the anterior end of inferior turbinate was recorded as NMC time. PEFR was measured using mini-Wright peak flow meter. Comparison between groups was analyzed using t-test and ANOVA in R statistical software. Results: NMC time was significantly prolonged in biomass fuel users (765.8 ± 378.16 s) in comparison to clean fuel users (545.4 ± 215.55 s). PEFR was significantly reduced (319.3 l/min) in biomass fuel users compared to clean fuel users (371.7 l/min). Women from lower socioeconomic status, lower literacy status, older undernourished women and women cooking for>15 years had prolonged Saccharin Transit Time (STT) and reduced PEFR. Conclusions: This study highlights the effects of indoor air pollution on respiratory defense mechanism. This simple noninvasive, inexpensive, screening test can be used as an early indicator of respiratory damage caused by exposure to air pollutants.

Exposures to fine particulate matter (PM 2.5 ) and birthweight in a rural-urban, mother-child cohort in Tamil Nadu, India

Background: Exposure to PM2.5 (fine particulate matter <less than 2.5 &mgr;m in aerodynamic diameter) related to ambient and household air pollution has been associated with low birthweight. Few of these studies, however, have been conducted in high exposure settings that are commonly encountered in low and middle income countries (LMICs). Objectives: We examined whether PM2.5 exposures during pregnancy were associated with birthweight in an integrated rural‐urban, mother‐child cohort in the state of Tamil Nadu, India. Methods: We recruited 1285 pregnant women in the first trimester of pregnancy from primary health care centers and urban health posts and followed them until birth to collect antenatal care data and birthweight. We estimated pregnancy period PM 2.5 exposures through direct serial measurements of 24‐h household PM2.5 concentrations, performed across each trimester. Mothers also completed detailed questionnaires to provide data on covariates related to household, socio‐economic, demographic and maternal health characteristics. The association between PM2.5 exposures and birth weight was assessed using linear and logistic regression models that controlled for potential confounders. Results: A 10‐&mgr;g/m3 increase in pregnancy period PM2.5 exposures was associated with a 4 g (95% CI: 1.08 g, 6.76 g) decrease in birthweight and 2% increase in prevalence of low birthweight [odds ratio(OR) = 1.02; 95%CI:1.005,1.041] after adjusting for gestational age, infant sex, maternal BMI, maternal age, history of a previous low birth weight child, birth order and season of conception. Conclusions: The study provides some of the first quantitative effects estimates for linking rural‐urban PM2.5 exposures and birthweight in India, adding important evidence for this association from high exposure settings in LMICs, that also experience dual health burdens from ambient and household air pollution. Study results also point to the need for considering maternal PM2.5 exposures alongside other risk factors for low birthweight in India HIGHLIGHTSProvides E‐R relationships between PM2.5 and birth‐weight in high exposure settings.Examines the association in a rural‐urban, mother‐child cohort in India.Estimates a 4g decrease in birth‐weight per 10‐&mgr;g/m3 increase in PM2.5 exposures.Estimates a 2% increase in low birth‐weight per 10‐&mgr;g/m3 increase in PM2.5 exposures.Maternal PM2.5 exposures may be an important risk factor for low birth‐weight in India.

Back to Basics – ‘Must Know’ Classical Signs in Thoracic Radiology

There are a few signs in radiology which are based on many common objects or patterns that we come across in our routine lives. The objective behind the association between such common objects and the corresponding pathologies is to make the reader understand and remember the disease process. These signs do not necessarily indicate a particular disease, but are usually suggestive of a group of similar pathologies which will facilitate in the narrowing down of the differential diagnosis. These signs can be seen in different imaging modalities like plain radiograph and computed tomography. In this essay, we describe 24 classical radiological signs used in chest imaging, which would be extremely helpful in routine clinical practice not only for radiologists but also for chest physicians and cardiothoracic surgeons.