Pratap Kumar Padhy

Domestic fuels, indoor air pollution, and children's health.

Reliance on solid biomass fuel for cooking and heating exposes many children of developing countries to high levels of indoor air pollution. This study investigates the association between household use of biomass fuels for cooking and prevalence of respiratory symptoms and diseases among children in rural India. The air‐quality parameters (CO, CO2, NO, NO2, SO2, O3, suspended particulate matter (SPM), including temperature and relative humidity) were investigated using a YES–Plus multigas air‐quality monitor for gaseous and Kimoto handy samplers (HS‐7) for TSPM. Seven hundred fifty households and 1505 children were selected for this study. A questionnaire developed on the pattern of the the International Study of Asthma and Allergies in Childhood (ISAAC) and the International Union Against Tuberculosis and Lung Disease (IUATLD) with some modifications were used for evaluation of respiratory health. The lung function parameters, namely, PEF, FVC, FEV1, FEF, and SVC were examined on an electronic Spiro Meter (Maestro Medline Ltd.). Logistic regression was used to estimate the odds of suffering from respiratory infections among children from households using biomass fuels relative to children from households using liquified petroleum gas (LPG), after controlling for potentially confounding factors. The study suggests that exposure to cooking smoke from biomass combustion is significantly associated with decline in lung function and prevalence of doctor‐diagnosed asthma (OR = 2.20; 95% CI: 1.16, 4.19) and other respiratory diseases.

Total non-methane volatile organic compounds (TNMVOC) in the atmosphere of Delhi

Volatile organic compounds (VOC), more specifically, non-methane volatile organic compounds (NMVOC) play a critical role in the atmospheric chemistry. NMVOC, through complex photochemical reactions, contribute to the formation of toxic oxidants, such as tropospheric ozone and PAN, which are injurious to health and highly phytotoxic. Certain NMVOC have been shown to be highly toxic, mutagenic and carcinogenic. NMVOC are receiving increasing attention in the west on account of their implication for human health and air quality. On the other hand, information on NMVOC in India and other developing countries is not available. As a result, appreciation of potential threat from NMVOC in relation to air quality and public health is sadly lacking among planners and policy makers. The paper deals with the estimation of total NMVOC at 13 sites in the urban environment of Delhi during November 1994 to June 1995. An inexpensive, labour intensive manual sample collection device was used and the air samples were analysed using GC-FID. The results show that the amount of NMVOC in the ambient environment of Delhi varied between 1.3 and 32.5 ppmv exhibiting wide temporal and seasonal variation. NMVOC levels mostly peaked at 0900 h, which coincide with the peak traffic hour. The implications of NMVOC build-up in the urban atmosphere are obvious for air quality. The results of this preliminary study make out a strong case for developing a regular monitoring programme for NMVOC in the urban environment of Delhi as well as in other major cities in the region.

Effects of biomass combustion smoke on hematological and antioxidant profile among children (8-13 years) in India.

The use of solid biomass fuel in traditional stoves has been associated with respiratory symptoms of chronic airway inflammation and higher rates of respiratory infections. The mechanisms of such associations remain unclear. In this study we examine the association between exposures to indoor pollution and the hematological and antioxidant profile in children. We found increases in the respiratory symptoms “cough without cold” [odds ratio (OR) 4.27; 95% confidence interval (CI) 3.00–4.95], “cough in the morning” (OR 3.80; CI 2.40–5.15), and “wheeze” (OR 3.60; CI 2.75–5.0) in children living in homes used solid biomass for cooking after adjustment for potential confounder variables. Children who lived in the households that cook with traditional biomass fuels had low hemoglobin and red blood cell (RBC) values, but raised white blood cell (WBC), neutrophil, and eosinophil counts. Furthermore, we examined the ascorbic acid, superoxide dismutase (SOD), and glutathione/oxidized glutathione (GSH/GSSG) ratio levels in the blood of the subjects and observed low levels of ascorbic acid (AA), SOD, and GSH/GSSG ratio in children lived in biomass used households. These findings suggest that the biomass smoke has the potential to produce oxidative stress and adverse health effects in children. There is much more work needed to confirm our conclusions. Investigating the mechanisms underlying air pollution-induced health problems would allow a more targeted approach to remove the most toxic components of air pollution, and could possibly provide a means to decrease individual sensitivity to air pollution.

Total Volatile Organic Compounds in the Urban Environment of Delhi

Total volatile organic compounds (TVOCs) in the urban ambient environment of Delhi were monitored from November 1994 to June 1995 at 13 sites using an inexpensive and a manual-labor-intensive sample collection procedure in want of sophisticated equipment. The results of the study show appreciable levels of TVOCs in the ambient environment of Delhi. The amount of TVOCs in the ambient environment was found to vary between 3 and 42 ppmv and exhibited wide temporal and seasonal variations. On a diurnal cycle, TVOC levels mostly peaked at 9:00 a.m., which coincided with the peak traffic hour. TVOC buildup in the urban atmosphere has serious implications for air quality through the formation of highly toxic oxidants. The results of this preliminary study make out a strong case for a regular monitoring of TVOCs in the urban environment of Delhi.

The role of earthworm Lampito mauritii (Kinberg) in amending lead and zinc treated soil

A laboratory experiment was carried out to determine the effect of earthworm (Lampito mauritii) activity on mobility of Pb2+ and Zn2+ in the soil (DTPA-extractable) and its composting potential in presence of these metals. Well clitellate earthworms collected from an uncontaminated site were exposed to different concentrations (75, 150, 300mgkg(-1)) of Pb2+ and Zn2+ separately for 30 days. It was observed that the metal burden in the earthworm tissue increased with the increase in metal treatment. L. mauritii elevated the soil pH of all the metal treated beds and lowered the soil C/N ratio in the cast by reducing the organic carbon and fixing additional nitrogen. Earthworm activity significantly increased the availability of phosphorous, potassium and decreased the amount of DTPA-extractable Pb2+ and Zn2+ in the cast, which implies the immobilization of metals in soils. These findings suggest the use of L. mauritii in amelioration of metal contaminated soil.

Effect of air and noise pollution on species diversity and population density of forest birds at Lalpahari, West Bengal, India

The Rajmahal-type quality stones for building purposes are found abundantly in Birbhum district, West Bengal, India, where stone mining and crushing have become the main industrial activity. Although crusher dust is injurious to health, demand for crushed stone is ever-increasing as a result of rapid infrastructural growth in the country. Most of the crusher units at Rampurhat are situated along the roadways adjacent to forest under Tumboni Beat of Rampurhat Range of Birbhum Forest Division. Excessive load of air pollution in this area has led to degradation of this forest. The status of the ambient air and noise level was evaluated. The effect of air and noise pollution on abundance and variability of birds in this forest have been compared to an almost non-polluted forest of the same bio-geographic zone. Both species diversity and population density of birds were found to decrease in the polluted forest, especially in the areas adjacent to crushers. For comparing the pollution status of two different forest sites and for establishing whether the density of birds have any correlation between the sites, the Students t-test and the chi-square test were applied respectively. Most of the results proved to be significant.

Assessment of Intra-urban Variability in Outdoor Air Quality and its Health Risks

Ambient air quality along with micrometeorological data was measured in a suburban area of India, from March 2006 to February 2007 in order to assess the intra-urban variability of air pollutants in different parts of the city. The prevalences of asthma and respiratory disorders were determined using a questionnaire survey of 750 adults. The association between intra-urban variability of air pollution and respiratory diseases were evaluated with logistic regression analyses. Compared with subjects staying 5.0 km away from a main road to those subjects living within 0.5 km and 1.0 km had odds ratios of 1.00 (95% CI, 0.85 to 1.50), 3.57 (95% CI, 3.00 to 3.95), and 3.00 (95% CI, 2.85 to 3.50), respectively for doctor-diagnosed asthma. A reduction of measured pollutant concentration with increase in distance from the main road was observed. The study demonstrated that residential exposure to highly trafficked roads is associated with respiratory diseases. Considering the continuing rise in motorized vehicle use and the paramount role of inhalation toxicology, these findings have high public health relevance and should be corroborated in prospective studies.

Effects of stone crushing industry on Shorea robusta and Madhuca indica foliage in Lalpahari forest

One of the various causes of forest decline is certainly the industrial expansion and the resultant air pollution of anthropogenic origin. Gradual and extensive encroachment of the forest area by the quarrying (mining) and crushing activities of the naturally occurring stones since early 1960s is found in the district of Birbhum, West Bengal, India. The aim of this study was to evaluate the effect of stone crushing industry on different foliar parameters of Shorea robusta and Madhuca indica which are two dominant broad–leaved tree species of the forest concerned. Measurement of suspended particulate matter (SPM), dustfall and gaseous pollutants in ambient air were done. Heavy deposition of dust particles on leaf surfaces was noted. Various types of foliar anomalies, both microscopic and macroscopic, were detected externally. Decrease in amount of chlorophyll and total carbohydrate in foliar tissues indicated reduction of photosynthesis. Reduction of protein content in foliar tissues was also noted. Site–wise and season–wise variations of almost all data were found to be statistically significant. Comparison of air pollution status and foliar biochemical parameters with those recorded in a control forest was done along with study of spatial significance between polluted sites at Lalpahari with increasing distance from the source of pollution. A significant correlation was established in many cases between foliar parameters and air pollutants present in ambient air in the highly polluted site of the forest close to the source of pollution.

Isolation and Characterization of Arsenic-Resistant Bacteria from Contaminated Water-Bodies in West Bengal, India

Bengal Basin is known for severe arsenic contamination. In the present study, we have isolated six bacteria from the arsenic contaminated surface water of Bengal Basin. 16S rDNA sequence analysis identified them as Microbacterium oleivorans, Acinetobacter soli, Acinetobacter venetianus, Acinetobacter junii, Acinetobacter baumannii, Acinetobacter calcoaceticus. All the isolates possess arsenic accumulation potential and high molecular weight plasmid (>10 kb). PCR amplification indicated the presence of arsenic-resistance genes (arsB and aoxB) either in the genome or plasmid or in both in the isolated bacteria (except in Acinetobacter venetianus). Exposure to arsenic affected bacterial growth and induced alteration in cytoplasmic membrane integrity.

Diatoms for assessing the ecological condition of inland freshwater bodies.

The ecological responses of diatoms to pollution and nutrient enrichment, caused by domestic and municipal sewage, in the five fresh water ponds have been examined. It was observed that diatoms were completely absent in P3 and some species were also absent in P1 and P2. Similarly, diatom diversity was lower in P1 and P2 than in P4 and P5. However, diatom abundance was higher in P4. The Biological Index for Diatoms indicates a better water quality in P4 and P5 than in P1, P2 and P3. It was suggested that diatoms are useful for biological monitoring of water quality.