Factors influencing Aerosol Characteristics over Urban Environment

Atmospheric aerosols are an important contributing factor to turbidity in urban areas besides having impact on health. Aerosol characteristics show a high degree of variability in space and time as anthropogenic share of total aerosol loading is quite substantial and is essential to monitor the aerosol features over long time scales. In the present study extensive observations of columnar aerosol optical depth (AOD), total columnar ozone (TCO) and precipitable water content (PWC) have been carried over a tropical urban city of Hyderabad, India. Significant variations of AOD have been observed during course of the day with low values of AOD during morning and evening hours and high values during afternoon hours. Spectral variation of AOD exhibits high AOD at smaller wavelengths and vice versa except a slight enhancement in AOD at 500 nm. Anomalies in AOD, particulate matter and black carbon concentrations have been observed during May, 2003. Back trajectory analysis of air mass during these episodes suggested variation in air mass trajectories. Analysis of the results suggests that air trajectories from land region north of study area cause high loading of atmospheric aerosols. The results are discussed in the paper.     

Characterization of aerosols from biomass burning--a case study from Mizoram (Northeast), India

Physical and optical properties of biomass burning aerosols in Northeastern region, India analyzed based on measurements made during February 2002. Large spatial extent of Northeastern Region moist tropical to moist sub-tropical forests in India have high frequency of burning in annual dry seasons. Characterization of resultant trace gases and aerosols from biomass burning is important for the atmospheric radiative process. Aerosol optical depth (AOD) observed to be high during burning period compared to pre- and post-burning days. Peak period of biomass burning is highly correlated with measured AOD and total columnar water vapor. Size distribution of aerosols showed bimodal size distribution during burning day and unimodal size distribution during pre- and post-burning days. Size distribution retrievals from biomass burning aerosols show dominance of accumulation mode particles. Weighted mean radius is high (0.22 microm) during burning period. Columnar content of aerosols observed to be high during burning period in addition to the drastic reduction of visibility. During the burning day Anderson sampler measurements showed dominance of accumulation mode particles. The diurnal averaged values of surface shortwave aerosol radiative forcing af biomass burning aerosols varies from -59 to -87 Wm(-2) on different days. Measured and modeled solar irradiances are also discussed in the paper.     

Effect of industrial effluent on properties of groundwater

Field survey was conducted to assess the quality of underground water in four major industrial areas of Hyderabad, Andhra Pradesh, and viz., Patancheru, Katedhan, Nacharam and Jeedimetla. Ground water samples were collected from wells at different lateral distances from the effluent streams i.e., starting from a minimum distance of 20 meters to a maximum distance of 620 meters from the effluent streams and analysed for different characteristics. The survey revealed that indiscriminate disposal of the effluent of industrial complexes around Hyderabad has aggrevated the acidity, EC, TDS, COD, Cl-, SO4(2-), PO4(3-), NO3-, F and heavy metals in the ground waters. As the sampling distance from the polluting stream increased a gradual improvement in the quality of ground water was noticed.     

Characterization of aerosols and its radiative impacts over urban and rural environments--a case study from Hyderabad and Srisailam

In the troposphere anthropogenic aerosol emissions are increasing in recent decades, which can influence the earth's climate. The present study addresses the characterization of aerosols and their radiative impacts over urban (Hyderabad) and rural (Srisailam) environments by using aerosol optical depth (AOD) measurements from MICROTOPS-II sunphotometer. AOD measurements over the urban site showed high values compared to the rural site. Over the urban environment aerosol forcing at the surface is as high as -42 W m(-2) and at the top of the atmosphere (TOA) is +10 W m(-2) whereas at the rural environment aerosol forcing at the surface has been observed to be -11 W m(-2) and at TOA it is observed to be +5.7 W m(-2). The difference between TOA and the surface forcing over the urban environment is +32 W m(-2) and over the rural environment is +5.3 W m(-2), which shows the absorption capacity of the respective atmospheres.     

Bacopa phospholipid complex retrieves aluminum maltolate complex–induced oxidative stress and apoptotic alterations in the brain regions of albino rat

Environmental Science and Pollution Research - Highly bioavailable plant phospholipid complex that can reverse aluminum maltolate (AlM)–induced toxicity is not yet reported. Hence, the...     

Shortwave radiative forcing efficiency of urban aerosols--a case study using ground based measurements

Aerosols reduce the surface reaching solar flux by scattering the incoming solar radiation out to space. Various model studies on climate change suggest that surface cooling induced by aerosol scattering is the largest source of uncertainty in predicting the future climate. In the present study measurements of aerosol optical depth (AOD) and its direct radiative forcing efficiency has been presented over a typical tropical urban environment namely Hyderabad during December, 2003. Measurements of AOD have been carried out using MICROTOPS-II sunphotometer, black carbon aerosol mass concentration using Aethalometer, total aerosol mass concentration using channel Quartz Crystal Microbalance (QCM) Impactor Particle analyser and direct normal solar irradiance using Multifilter Rotating Shadow Band Radiometer (MFRSR). Diurnal variation of AOD showed high values during afternoon hours. The fraction of BC estimated to be approximately 9% in the total aerosol mass concentration over the study area. Results of the study suggest -62.5 Wm(-2) reduction in the ground reaching shortwave flux for every 0.1 increase in aerosol optical depth. The results have been discussed in the paper.     

Modulating effect of Phyllanthus fruit extract against lead genotoxicity in germ cells of mice

The objective of the present study was to evaluate the protective effect of Phyllanthus emblica against clastogenicity induced by lead nitrate on the incidence of sperm head abnormalities in the germ cells of mice. At higher concentration of lead, a significant increase in the percentage of sperm head abnormalities was noted but when animals primed with Phyllanthus fruit extract (PFE), a reduction in the frequency of sperm head abnormalities was observed. It can be suggested from the above study that Phyllanthus emblica plays a key role in inhibition of heavy metal mutagenesis in mammals.     

Comparative account of certain enzymes in the serum of homo-iothermal vertebrates subjected to production of myocardial infarction by isoproterenol hydrochloride

Myocardial infarction was produced by subcutaneous administration of isoproterenol hydrochloride (85 mg/kg b.w. for two consecutive days). The myocardial damage was proved by observing increase in the activity of SGOT and SGPT in serum whereas AChE activity was inhibited by increasing Km, without affecting Vmax. The inhibition of AChE and inhibitory kinetic may be useful in the diagnosis and management of salvage of myocardium.     

Effects of paint particles inhalation on superoxide dismutase and glutathione peroxidase activities in industrial painters

The aim of this study was to examine effects of lead (Pb)-based paints on malondialdehyde (MDA) levels as an indicator for lipid peroxidation; and on activities of serum antioxidant enzymes activities such as superoxide dismutase (SOD) and glutathione peroxidase (GPx) in industrial painters. A total of 67 male painters and 50 age-matched and gender-matched controls were included in this cross-sectional study. There were 19 smokers and 48 non-smokers in the paint-exposed group and 20 smokers and 30 non-smokers in the control group. Hemoglobin concentrations were lower in painters’ blood compared to controls. The blood Pb concentrations were higher in painters compared to controls. SOD and GPx activities were significantly lower in painters compared to controls. MDA concentration was found to be significantly elevated. Smoking was found to be a major confounder. Data suggest that Pb-based paints affect oxidant parameters in occupationally exposed workers.     

Urban soil quality of Raipur,Chhattisgarh, India

Soil quality in urban areas in India is degraded due to multiple anthropogenic activities. The objectives of this work are to determine the concentration variations, toxicity, and sources of carbons, metals, and ions in the surface soil of Raipur, the industrialized capital city of Chhattisgarh state, India. High concentrations of Al, K, Ca, Ti, Fe, and elemental carbon (EC) were registered. Relatively lower concentrations of V, Cr, Mn, Ni, Cu, Zn, Sr, Ba, Pb, organic carbon (OC), and carbonate carbon (CC), as well as ions (viz. F^–, Cl^–, NO₃^–, SO₄^2–, Na⁺, K⁺, Mg²⁺, and Ca²⁺), were also recorded. EC was found to be one of the major pollutants, although enrichment factors pointed to high contamination with SO₄^2–, K⁺, Mg²⁺_, Cr, Mn, and Pb; and extreme contamination with NO₃^– and Ca²⁺. The spatial and temporal variations, enrichment factors, toxicity, and sources of the chemical species detected in the soil are discussed.