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Abstract The vertical dispersion parameter of Pasquill–Gifford needs some modification in the close vicinity of urban roadways by considering the influence of traffic-induced turbulence. Wind tunnel simulation experiments have been carried out with controlled traffic parameters to evaluate traffic-induced effect on vertical dispersion parameter (σz) in the near field of roadways. The aerodynamic similarities in atmospheric flow, vehicles size and speeds have been considered with appropriate similarity criteria. The tracer gas experiments have been performed to evaluate σz in the near field of the roadways for variable traffic volumes and two approaching wind directions (i.e. 90○ and 60○). The results showed that the value of σz increased monotonically with increase in traffic volumes and becomes nearly constant at a particular downwind distance. It has also been found that the σz was considerably affected by approaching wind directions. Further, the comparison of experimental σz values for both approaching wind directions with those of Chock (1978) and Rao and Keenan (1980), showed an agreement within ±15%. [ABSTRACT FROM AUTHOR]

Setting: Field sites in 12 districts in different parts of India., Objective: To determine the nationwide population prevalence of and risk factors for asthma and chronic bronchitis (CB) in adults., Design: A standardised validated questionnaire based on the International Union Against Tuberculosis and Lung Disease's 1984 questionnaire was used to assess asthma and CB prevalence. Multivariate logistic regression analyses were performed to determine the risk factor associations. Estimates standardised to the 2011 population projection estimates for India were used to calculate the national disease burden., Results: A total of 85,105 men and 84,470 women from 12 urban and 11 rural sites were interviewed. One or more respiratory symptoms were present in 8.5% of individuals. The overall prevalence of asthma and CB was respectively 2.05% (adults aged ≥15 years) and 3.49% (adults aged ≥35 years). Advancing age, smoking, household environmental tobacco smoke exposure, asthma in a first-degree relative, and use of unclean cooking fuels were associated with increased odds of asthma and CB. The national burden of asthma and CB was estimated at respectively 17.23 and 14.84 million., Conclusion: Asthma and CB in adults pose an enormous health care burden in India. Most of the associated risk factors are preventable.

Background & Objectives: Exposure to ozone and asthma are both associated with increased oxidative stress. Exposure to ozone therefore, may potentiate the airway response to allergens. We undertook this study to investigate the effect of ozone exposure on airway response to ovalbumin in sensitized guinea pigs and its modulation by dietary supplementation with antioxidant vitamins C and E., Methods: After in vivo measurements of specific airways conductance (SGaw) and airway hyperresponsiveness (AHR) to inhaled histamine, guinea pigs were sensitized to ovalbumin and divided into three groups: (i) sensitized; (ii) sensitized and exposed daily to ozone; and (iii) sensitized, exposed daily to ozone and given dietary supplementation with vitamin C, 2 mg/kg body wt and E, 7 IU/kg body wt. A control group of nonsensitized animals was included. After 4 wk, AHR was measured again and animals were challenged with inhaled ovalbumin. Changes in SGaw were followed for early and late airway bronchoconstrictive responses. The following measurements were obtained: (i) parameters of oxidative stress--plasma malonaldehyde (MDA) as marker of lipid peroxidation and superoxide anion generation by leukocytes and bronchoalveolar lavage (BAL) cells; (ii) antioxidant status: red cell superoxide dismutase (SOD); and (iii) glutathione peroxidase (GPx). BAL cytology was studied., Results: Ozone exposure resulted in an increase in AHR and early and late bronchoconstrictive responses after ovalbumin challenge, greater superoxide anion generation in BAL cells, higher plasma MDA levels and decrease in red cell SOD activity. Dietary supplementation with vitamin C and E prevented or ameliorated these responses., Interpretation & Conclusions: Exposure to ozone at concentrations of 0.12 ppm for 2 h daily for 4 wk enhances the airway response to allergens in sensitized guinea pigs. Dietary supplementation with antioxidant vitamins E and C, affords variable degree of protection against this enhancement.

Aim: This study was an attempt, to determine chronological age, dental age and skeletal age, and to establish interrelationship, amongst the dental, skeletal and chronological ages and their differences if any between rural and urban female children. The study included 80 girls aged 8 to 14 years from rural and urban areas., Material and Methods: The subjects were divided into 4 Groups: Group I, II, III, and IV. Group I and II comprising of rural female subjects, wherein Group I comprised of 8 to 11 years and Group II comprised of 11 to 14 years old females. Group III and IV comprising of urban females wherein Group III included 8 to 11 years and Group IV comprised of 11 to 14 years old females. Orthopantomograms and hand and wrist radiographs were taken. The calcification status of permanent teeth was evaluated from orthopantomograms, and dental age was calculated according to Demirjian's method. The stages of ossification of various carpal bones were evaluated from the hand-wrist radiograph using radiographic atlas of Greulich and Pyle and skeletal age was calculated. The chronological age was recorded from the actual date of birth., Results: Data collected was statistically analyzed., Conclusion: Highly significant correlation was observed between dental and skeletal age (r=0.752, p-value < 0.01) in total sample. Strong correlation of chronological age with dental and skeletal age was also observed (r=0.650, r = 0.620, respectively). Out of all three correlations, dental age and skeletal age had the maximum correlation in total sample. While comparing rural and urban sample as regard to ages or correlations no significant difference was found (p-value < 0.01).

Background: The effect of any legislation depends on its implementation. Limited studies indicate that tobacco companies may tend to use such provision for surrogate advertising. The point of sale advertisement provision has been placed in the Indian Tobacco Control legislation. The study was undertaken to assess the Indian scenario in this regard., Objective: To assess if there are any violations related to provision of point of tobacco sale advertisements under India's comprehensive tobacco Control legislation in different parts of India., Materials and Methods: Boards over various shops showing advertisements of tobacco products were observed in the cities of Delhi, Mumbai, Kolkata, Trivandrum and Jaipur, between September 2005 and March 2006., Results: The point of sale advertisements mushroomed after the implementation of 2004 tobacco control legislation. Tobacco advertisement boards fully satisfying the point of sale provision were practically non-existent. The most common violation of point of sale advertisements was the larger size of the board but with tobacco advertisement equal to the size indicated in the legislation and remaining area often showing a picture. Invariably two boards were placed together to provide the impression of a large single repetitive advertisement. More than two boards was not common. Tobacco advertisement boards were also observed on closed shops/ warehouses, shops not selling tobacco products and on several adjacent shops., Conclusion: The purpose of the point of sale advertisements seems to be surrogate advertisement of tobacco products, mainly cigarettes.

Background: There is limited information on field epidemiology of bronchial asthma in Indian adults., Objectives: To estimate prevalence of bronchial asthma in different regions of India and to define risk factors influencing disease prevalence., Methods: A field study was conducted at Chandigarh, Delhi, Kanpur and Bangalore through a two stage stratified (urban/ rural) sampling and uniform methodology using a previously validated questionnaire. Asthma was diagnosed if the respondent answered affirmatively both to (a) whistling sound from chest, or chest tightness, or breathlessness in morning, and (b) having suffered from asthma, or having an attack of asthma in the past 12 months, or using bronchodilators. Besides demographic data, information on smoking habits, domestic cooking fuel used, atopic symptoms, and family history suggestive of asthma was also collected. Univariate and multivariate logistic regression modelling was performed to calculate odds ratio of various potential risk factors., Results: Data from 73605 respondents (37682 men, 35923 women) were analysed. One or more respiratory symptoms were present in 4.3-10.5% subjects. Asthma was diagnosed in 2.28%, 1.69%, 2.05 and 3.47% respondents respectively at Chandigarh, Delhi, Kanpur and Bangalore, with overall prevalence of 2.38%. Female sex, advancing age, usual residence in urban area, lower socio-economic status, history suggestive of atopy, history of asthma in a first degree relative, and all forms of tobacco smoking were associated with significantly higher odds of having asthma., Conclusion: Prevalence estimates of asthma in adults in this study, although lower than several previously reported figures, point to a high overall national burden of disease.

Introduction: Population prevalence of chronic obstructive pulmonary disease (COPD) and its relationship with tobacco smoking, environmental tobacco smoke (ETS) exposure and other variables were studied in adult subjects of 35 years and above at four different centres in India. Question-items for the diagnosis of COPD were included in the questionnaire used for the field study on asthma epidemiology., Methods: Field surveys were conducted in both the urban and the rural populations at Bangalore, Chandigarh, Delhi and Kanpur with the help of a structured and validated questionnaire for diagnosis of asthma and COPD. Separate sets of questions were used for the diagnoses of the two diseases. A two-stage stratified sample design was employed where a village or an urban locality formed the first stage unit and a household formed the second stage unit. A uniform methodology was used at all the four centres and the analyses were done at the central coordinating centre--Chandigarh. Chronic obstructive pulmonary disease, defined by chronic bronchitis (CB) criteria, was diagnosed from the presence of cough and expectoration on most of the days for at least three months in a year for two consecutive years or more., Results: Chronic obstructive pulmonary disease was diagnosed in 4.1% of 35295 subjects, with a male to female ratio of 1.56:1 and a smoker to nonsmoker ratio of 2.65: 1. Prevalence among bidi and cigarette smokers was 8.2% and 5.9%, respectively. Odds ratio (OR) for COPD was higher for men, elderly individuals, lower socio-economic status and urban (or mixed) residence. Environmental tobacco smoke exposure among nonsmokers had an OR of 1.4(95% CI 1.21-1.61). Combined exposure to both ETS and solid fuel combustion had higher OR than for ETS exposure alone., Conclusions: Population prevalence of COPD is very high in India with some centre to centre differences. Smoking of both bidis and cigarettes, and ETS exposure among nonsmokers, were two important risk factors at all centres. It is important to employ uniform methodology for assessment of national burden and disease-surveillance programme.

Background: Population prevalence of tobacco smoking especially with reference to detailed habits such as the amount smoked, the smoking forms, quit-rates and relationship with demographic variables were studied at four different centres in India along with the study on epidemiology of asthma and chronic obstructive pulmonary disease., Methods: The study population included adults of over 15 years of age selected with two-stage stratified random sample design. A specifically designed questionnaire was used for the study., Results: There were 11496 (15.6%) ever smokers in the study sample of 73605 subjects. Among 37682 males, 10756 (28.5%) were ever smokers and among 35923 females, 740 (2.1%) were ever smokers. Bidi was the commonest form of smoking, more so in the rural areas. The mean number of cigarettes/bidis smoked per day was 14 (+/- 11.5) and the mean age of starting smoking was 20.5 (+/- 20.0) years. Increasing age, low socio-economic status and rural residence were important factors associated with smoking. Vigorous anti-tobacco measures under the tobacco control programmes yielded only a quit-rate of 10 percent. Nearly 14% of ever smokers had some respiratory symptoms., Conclusions: A substantial proportion of population in India has current or past smoking habit with higher prevalence among males than females. The quit-rates have been low in spite of the various anti-tobacco measures. There is a significant respiratory morbidity associated with smoking.

Background: Exposure to environmental tobacco smoke (ETS) is a risk factor for childhood asthma. Its association with asthma in adults is less clear., Methods: In a multicentric population study on asthma prevalence in adults, specific enquiries were made into childhood and adulthood exposure to household ETS, and its relationship with asthma diagnosis were analysed., Results: From a total of 73605 respondents, 62109 were studied after excluding current or past smokers. Overall observed prevalence of asthma was 2.0% (men 1.5%,women 2.5%, p < 0.001). Of all asthma patients, history of ETS exposure was available in 48.6 percent. Prevalence of asthma in the ETS exposed subjects was higher compared to non-exposed individuals (2.2% vs 1.9%, p < 0.05). Multiple logistic regression analysis showed a higher risk of having asthma in persons who were exposed to ETS compared to those not exposed (odds ratio [OR] 1.22, 95% CI 1.08-1.38) after adjusting for age, gender, usual residence, exposure to biomass fuels and atopy. Stratification of ETS exposure revealed that exposure during childhood and both during childhood and adulthood were significantly associated with asthma prevalence. Exposure only in adulthood was not a significant risk factor (OR 1.13, 95% CI 0.95-1.33). Persons reporting combined environmental tobacco smoke exposure from parents during childhood and spouse during adulthood had highest risk of having asthma (OR 1.69, 95% CI 1.38-2.07). Environmental tobacco smoke exposure was also significantly associated with prevalence of respiratory symptoms such as wheezing, cough and breathlessness., Conclusions: Environmental tobacco smoke exposure during childhood is an important risk factor for asthma and respiratory symptoms in non-smoking adults.

Background: There is paucity of information on health-related expenditure attributed to smoking in India. This community study estimated the expenditure on healthcare and morbidity borne by families of smokers and compared these with those of families without smokers. It was hypothesized that families with smokers were likely to have a higher health expenditure than non-smoker families attributable to the increased probability of health problems associated with smoking., Methods: The study population comprised 1000 urban and rural families divided into two groups. Group I consisted of 500 families with one or more smoker(s) while group II comprised 500 families without a smoker. Both groups had an equal representation from the urban and rural populations (250 each). The study team used a structured, generally close-ended questionnaire, pre-tested for its validity and reliability, to interview the families. Different components of health-related expenditure and other morbidity indices were studied. Each family was studied in two phases: (i) initially, for the retrospective assessment of expenditure and other losses during the preceding one year, and (ii) prospectively, for the following 10 months on repeated visits and estimations made every two months. The data collected retrospectively were mostly incomplete and could not be used for analyses., Results: The number of family members reporting sick was significantly higher in group I than in group II among both urban and rural families (p < 0.001). There was an excess expenditure of Rs 730 and Rs 141, in addition to Rs 4209 and Rs 894 on smoking products in group I families in urban and rural areas, respectively. Univariate analysis showed that the odds ratio for having any health-related expenditure for a group I family was 3.346 (95% confidence interval 2.533-4.420), which was highly significant (p < 0.0001). The differences in loss of work on account of illness and loss of man-days among members of groups I and II were not significant. However, the number of lost school days among children of group I families, loss of efficiency of its members and change of jobs due to loss of efficiency were highly significant., Conclusion: The direct healthcare costs as well as the indirect fiscal losses are higher in families with one or more smoker(s).

Ventricular tachycardia occurs infrequently in patients without structural heart disease. These tachycardias commonly originate from the right ventricular outflow tract. However, the presence of more than one arrhythmogenic substrate in a patient without structural heart disease is rare. We report such a 48-year old patient with no structural heart disease who presented with three morphology wide QRS tachycardia. A brief review of the pathophysiology and management is discussed.

Dipyridamole nuclear myocardial perfusion test is a safe and effective alternative to exercise nuclear perfusion testing for detecting myocardial ischemia. It is the procedure of choice in selected patients who are unable to exercise adequately. Intravenous dipyridamole causes coronary vasodilation with resultant maldistribution and heterogeneity of coronary flow in the presence of significant coronary artery disease. True ischemia, causing symptoms or ST-segment depression, is uncommon, in part because there is no increase in myocardial oxygen demand. A patient in whom myocardial ischemia developed, manifested by ST-segment elevation, during dipyridamole stress testing is described. Scintigraphic images illustrated a myocardial perfusion defect, which was consistent with coronary angiographic findings. This case report addresses the importance of dipyridamole-induced ST-segment elevation, its correlation with angiographic findings, and the need for continued hemodynamic and electrocardiographic monitoring in patients following dipyridamole infusion.

Background: Pan masala-containing tobacco (PM-T) was introduced in the Indian market during the 1970s. It is a mixture of areca nut, tobacco, lime, catechu and spices. Despite mounting evidence of health hazards of tobacco, tobacco manufacturers as well as policy-makers often seek evidence regarding the carcinogenicity of newer tobacco mixtures such as PM-T., Methods: All the studies on pan masala (with or without tobacco) listed on MEDLARS, and the studies known to the expert committee on the subject constituted by the Directorate General of Health Services, were reviewed. The studies on individual components and PM-T like substances were also reviewed. The interpretation of carcinogenicity of PM-T has been made, based on studies on (i) PM-T; (ii) PM-T like mixtures; and (iii) the effect of individual ingredients of PM-T and the likely effect of their combination., Results: Studies on Chinese hamster ovary cells and Ames test indicate that PM-T is mutagenic. There is limited evidence that it may be carcinogenic to animals. The proportion of areca nut and tobacco in PM-T is in between the proportion of these substances in two known tobacco-areca nut mixtures of India (Mainpuri tobacco and mawa). Studies on Mainpuri tobacco indicate that it is carcinogenic, while literature suggests an association between mawa use and oral submucous fibrosis., Conclusion: Human studies on PM-T like mixtures and the limited studies on PM-T suggest that PM-T is likely to be carcinogenic.