An investigation of potential regional and local source regions affecting fine particulate matter concentrations in Delhi, India.

In this study, potential regional and local sources influencing PM2.5 (particulate matter with an aerodynamic diameter >2.5 µm) concentrations in Delhi, India, are identified and their possible impact evaluated through diverse approaches based on study of variability of synoptic and local airflow patterns that transport aerosol concentrations from these emission sources to an urban receptor site in Delhi, India. Trajectory clustering of 72-hr and 48-hr back trajectories simulated at arrival heights of 500 m and 100 m, respectively, every hour for representative years 2008-2010 are used to assess the relative influence of long-distance, regional, and subregional sources on this site. Nonparametric statistical procedures are employed on trajectory clusters to better delineate various distinct regional pollutant source regions. Trajectory clustering and concentration-weighted trajectory (CWT) analyses indicate that regional and subregional PM2.5 emission sources in neighboring country of Pakistan and adjacent states of Punjab, Haryana, and Uttar Pradesh contribute significantly to the total surplus of aerosol concentrations in the Delhi region. Conditional probability function and Bayesian approach used to identify local source regions have established substantial influence from highly urbanized satellite towns located southwest (above 25%) and southeast (above 45%) of receptor location. There is significant seasonal variability in synoptic and local air circulation patterns, which is discerned in variability in seasonal concentrations. Mean of daily averaged PM2.5 concentrations at the Income Tax Office (ITO) receptor site over Delhi at 95% confidence level is highest in winter, ranging between 209 and 185 µg m⁻³ for the entire study period. The annual variability in air transport pathways is more in winter than in other seasons. Year-to-year variability is present in aerosol concentrations, especially during winter, with standard deviations varying from a minimum of 60 µg m⁻³ in winter 2009 to a maximum of 109 µg m⁻³ in winter 2010.

Dietary risk factors for hypopharyngeal cancer in India.

OBJECTIVE: The Indian subcontinent has among the highest rates of hypopharyngeal cancer worldwide. The purpose of this study was to examine the associations between the Indian diet and hypopharyngeal cancer. METHODS: We used data from a hospital-based case-control study of 513 incident hypopharyngeal cancers and 718 controls from four centers in India. Dietary information was assessed using a 67-item semi-quantitative food frequency questionnaire. Intakes of related foods were combined across food groups and were categorized by quartile. We used unconditional logistic regression modeling, stratified by ever tobacco use, to analyze the association between food intakes and hypopharyngeal cancer. RESULTS: Among persons who had ever smoked or chewed tobacco, protective associations were seen at the highest quartiles of total fruit intake (OR = 0.37, 0.20-0.69), curds (OR = 0.35, 0.17-0.69), and leafy green (OR = 0.25, 95% CI 0.13-0.51), root (OR = 0.22, 95% CI 0.11-0.43), and cruciferous vegetable intakes (OR = 0.41, 0.20-0.84). Results were similar, although not as robust, among persons who had never smoked or chewed tobacco. An increased risk of disease was seen among tobacco users who drank milk daily (OR = 1.84, 1.14-2.98). CONCLUSIONS: Dietary factors might contribute to the high risk of hypopharyngeal cancer observed in India.

Assessment of awareness level on tobacco and smoking habits as risk factors for cancer among lung and laryngeal cancer patients in Kolkata--a case control study.

The burden of tobacco related cancers is increasing alarmingly throughout the world; therefore tobacco control merits the highest priority in the fight against cancer worldwide. The present report concerns a case control study of males with cancers of lung and larynx, to assess tobacco use, level of exposure and the awareness of risk of tobacco as a main cause of cancer. A total of 217 new patients with cancer of lung and larynx registered at Chittaranjan National Cancer Institute were recruited for the study, along with 200 healthy male (age, religion and residential status matched ) visiting controls. Information on socio-demographic parameters, details of the disease, tobacco use, and awareness about effects of tobacco were obtained through a standardized questionnaire. Smokers were at a higher risk of disease than nonsmokers, with a direct correlation between duration and number of smoking, monthly income, family size and education level. Adjusted ORs observed for smokers for duration more than 40 years of smoking and smoking more than 40 beedi/cigarettes per day were 4.3 and 3.9, respectively. Awareness level towards tobacco chewing, active and passive smoking revealed poor response among the subjects. Thus improved health education for antismoking and awareness generation of tobacco hazards should be strongly recommended as a preventive measure.

Tobacco control practices in 25 schools of West Bengal.

Information about tobacco use prevalence, knowledge and attitude was assessed among school personnel in schools of West Bengal. Statistical analysis was done using SUDAAN and the C-sample procedure in Epi-Info. The school response rate was 100%. Current any smoking and smokeless tobacco use was reported by 30.9% and 13.1% school personnel, respectively. Current daily smoking, and smokeless tobacco use reported by 20.4%, and 5.8% school personnel respectively. Men reported significantly more for all kinds of daily tobacco use as compared to women. School tobacco control policy on three scales was reported poor (17.7-30%). However most of the school personnel felt need for such policies (82.7-93.6%). Teaching and training on tobacco was reported low (29.9%-50.4%). However most of the school personnel (79.1-93.6%) were supportive on different measures of tobacco control. Training of school personnel may provide students with essential tools to help them adopt and maintain a smoke free lifestyle.

Human papillomavirus genotype distribution in cervical cancer in India: results from a multi-center study.

The prevalence of HPV genotypes in cervical cancer differs in various regions, though types 16 and 18 generally account for the majority. Knowledge of HPV genotypes in cervical cancer covering the diverse Indian population is important in consideration of the potential future impact of HPV prophylactic vaccination and HPV-based screening strategies. To determine HPV genotype distribution in cervical cancers representing different regions a total of 278 cervical cancer cases were enrolled from cancer centers in North, East, Central and South India. Cervical scrape specimens were tested for HPV DNA using the MY09/11 L1 consensus PCR method followed by sequencing for genotyping, as well as for HPV mRNA utilizing the PreTectTM HPV-Proofer assay. In instances of negative or discrepant results between the two tests, biopsy specimens were tested. HPV DNA and/or mRNA were detected in 91.7% of the cases. Genotype 16 was the most common type, detected alone in 59.4% and in association with type 18 in 3.6% of cases. Genotype 18 was detected as a monotype in 13.3% cases. In total, types 16 and 18 alone or in co-infection with each other were detected in 76.3% cases. Genotype 33 was the third most common type. Overall, genotypes 16, 18, 31, 33, and 45 were the five most common types, detected in 87.1% of the total cases. There were no significant regional differences. In conclusion, the currently available HPV prophylactic vaccines targeting types 16 and 18 have the potential to reduce the burden of cervical cancer in India by over 75%.

Indoor air pollution from solid fuels and risk of hypopharyngeal/laryngeal and lung cancers: a multicentric case-control study from India.

BACKGROUND: A recent monograph by the International Agency for Research on Cancer (IARC) has identified indoor air pollution from coal usage as a known human carcinogen, while that from biomass as a probable human carcinogen. Although as much as 74% of the Indian population relies on solid fuels for cooking, very little information is available on cancer risk associated with these fuels in India. METHODS: Using data from a multicentric case-control study of 799 lung and 1062 hypopharyngeal/laryngeal cancer cases, and 718 controls, we investigated indoor air pollution from various solid fuels as risk factors for these cancers in India. RESULTS: Compared with never users, individuals who always used coal had an increased risk of lung cancer [odds ratio (OR) 3.76, 95% confidence interval (CI) 1.64-8.63]. Long duration of coal usage (>50 years) was a risk factor for hypopharyngeal (OR 3.47, CI 0.95-12.69) and laryngeal (OR 3.65, CI 1.11-11.93) cancers. An increased risk of hypopharyngeal cancer was observed among lifelong users of wood (OR 1.62, CI 1.14-2.32), however this was less apparent among never-smokers. Increasing level of smokiness inside the home was associated with an increasing risk of hypopharyngeal and lung cancer (P(trend) < 0.05). CONCLUSION: This study showed differential risks associated with indoor air pollution from wood and coal burning, and provides novel evidence on cancer risks associated with solid fuel usage in India. Our findings suggest that reducing indoor air pollution from solid fuels may contribute to prevention of these cancers in India, in addition to tobacco and alcohol control programs.

Smokeless tobacco and increased risk of hypopharyngeal and laryngeal cancers: a multicentric case-control study from India.

Hypopharyngeal and laryngeal cancers are among the most common cancers in India. In addition to smoking, tobacco chewing may be a major risk factor for some of these cancers in India. Using data from a multicentric case-control study conducted in India that included 513 hypopharyngeal cancer cases, 511 laryngeal cancer cases and 718 controls, we investigated smoking and chewing tobacco products as risk factors for these cancers. Bidi smoking was a stronger risk factor compared to cigarette smoking for cancer of the hypopharynx (OR(bidi) 6.80 vs. OR(cig) 3.82) and supraglottis (OR(bidi) 7.53 vs. OR(cig) 2.14), while the effect of the 2 products was similar for cancer of the glottis (OR(bidi) 5.32 vs. OR(cig) 5.74). Among never-smokers, tobacco chewing was a risk factor for hypopharyngeal cancer, but not for laryngeal cancer. In particular, the risk of hypopharyngeal cancer increased with the use of Khaini (OR 2.02, CI 0.81-5.05), Mawa (OR 3.17, CI 1.06-9.53), Pan (OR 3.34, CI 1.68-6.61), Zarda (OR 3.58, CI 1.20-10.68) and Gutkha (OR 4.59, CI 1.21-17.49). A strong dose-response relationship was observed between chewing frequency and the risk of hypopharyngeal cancer (p(trend) < 0.001). An effect of alcohol on cancer of the hypopharynx and supraglottis was observed only among daily drinkers (OR 2.22, CI 1.11-4.45 and OR 3.76, CI 1.25-11.30, respectively). In summary, this study shows that chewing tobacco products commercially available in India are risk factors for hypopharyngeal cancer, and that the potency of Bidi smoking may be higher than that of cigarette smoking for hypopharyngeal and laryngeal cancers.