Environmental radon studies using solid state nuclear track detectors

The results of radon activity recorded in 70 dwellings of Nurpur area, Kangra district, Himachal Pradesh, India are reported. LR-115 Type 2 films in the bare mode were exposed for four seasons of three months each covering a period of one year for the measurement of indoor radon levels. The calibration constant of 0.020 tracks cm(-2) d(-1) per Bq m(-3) has been used to express radon activity in Bq m(-3). The annual average indoor radon concentrations in 17 different villages of the area are found to vary from 168+/-46 to 429+/-71. Most of the indoor radon values lie in the range of action levels (200-600 Bq m(-3)) recommended by International Commission on Radiological Protection.     

The Truth about Public Health Protection and Community Sewerage and Water Supply Sanitation in Developing Countries

Since the establishment, following World War II, of the World System, by which the affluent industrialized countries established various international assistance agencies (including the multilateral development banks, UN affiliates, and Bilaterals), these assistance agencies have invested very large sums in helping finance planning and construction of community sewerage and water supply facilities in the developing countries. However, much of this large investment has been ineffective and wasted, primarily because of the lack of understanding by the staff of the assistance agencies that the design criteria for the facilities must be modified to suit the socio-economic status of the developing country. The developing countries are relatively very poor in terms of available finances, hence cannot afford to emulate Western environmental standards and design practices, especially as related to operation and maintenance, hence much simpler approaches must be used. Experiences in several Asian countries are discussed, and a recommendation is made on how to go about resolving this problem.     

Effect of DDVP on the histology and AChE kinetics of heart muscles of Rattus norvegicus

The LD50 of DDVP (Dichloro, dimethyl vinyl phosphate) for Rattus norvegicus was 21.4 mg/kg. b.w. The two sub lethal doses 1 and 3 mg/kg showed many histopathological changes in the working heart muscles and also showed significant necrosis in this S-A node, A-V node and bunble of His of the cardiac conducting system. These sublethal doses of the OP pesticide caused a significant inhibition of AChE. The maximum inhibition was noticed at the highest dose. The enhanced inhibitory constant Km and ACh contents in the heart muscles with the increase of dose showed inhibition of enzyme. The constant Vmax showed competitive nature of inhibition. A significant inhibition of AChE (69%) indicated that DDVP is a strong inhibitor of enzyme in heart.     

Monitoring and modelling of indoor radon concentrations in a multi-storey building at Mumbai,India

Radon (Rn(222)) levels in an indoor atmosphere of a multi-storey building at Mumbai have been measured for one year covering all the four seasons. Monitoring was carried out using the time-integrated passive detector technique, using Kodak-115 type Solid State Nuclear Track Detector (SSNTD) films of 2.5x2.5 cm size. Measured indoor radon levels showed a decreasing trend with height with concentration ranging from 41 Bq m(-3) at ground floor level to 15 Bq m(-3) at 19th floor level. Using the dose conversion factors, the inhalation dose due to breathing of radon gas is estimated to be 1.03 mSv y(-1) at the ground floor to 0.38 mSv y(-1) at the 19th floor level. Measured indoor radon concentrations on each floor were compared with the computed values using a mathematical model. The agreement between measured values and calculated values of indoor concentrations at different floors was very good within the limitations of various field parameter values.     

Profenofos residues in wild fish from cotton-growing areas of New South Wales, Australia

The organophosphorus (OP) pesticide profenofos (O-4-bromo-2-chlorophenyl O-ethyl S-propyl phosphorothioate) is used heavily in cotton-growing areas of eastern Australia toward the end of the growing season. European carp (Cyprinus carpio), bony bream (Nematalosa erebi), and mosquitofish (Gambusia holbrooki) were collected from the cotton-growing areas around Wee Waa, New South Wales, to determine the relationship between profenofos residues and acetyl-cholinesterase (AChE) activity in wild fish. Profenofos concentrations in water, sediment, and fish tissue reflected its general level of use; levels in March 1994 were significantly higher than in 1993 and generally decreased in May, 6 wk after cessation of spraying. Residues in carp and bony bream generally correlated with concentrations in water and sediment, although residues in fish tend to persist longer at some sites. Acetylcholinesterase inhibition was a useful indicator of profenofos exposure within a season, particularly if linked with residue measurements. Bony bream and gravid female mosquitofish recovered AChE levels more slowly than carp or nongravid mosquitofish. Recovery in creeks was generally more rapid than in lagoons.     

Entrainment mortality of Ichthyoplankton: Detectability and precision of estimates

The ability to detect and to develop a precise and accurate estimate of the entrainment mortality fraction is an important step in projecting power plant impacts on future fish population levels. Recent work indicates that these mortailities may be considerably less than 100% for some fish species in the early life stages. Point estimates of the entrainment mortality fraction have been developed based on probabilistic arguments, but the precision of these estimates has not been studied beyond the simple statistical test of the null hypothesis that no entrainment mortaility exists.The ability to detect entrainment mortality is explored as a function of the sample sizes (numbers of organisms collected) at the intake and discharge sampling stations of a power plant and of the proportion of organisms found alive in the intake samples (intake survival). Minimum detectable entrainment mortality, confidence interval width, and type II error (probability of accepting the null hypothesis of no entrainment mortality when there is mortality) are considered. Increasing sample size and/or decreasing sampling mortality will decrease the minimum detectable entrainment mortality, confidence interval width, and type II error for a given level of type I error.The results of this study are considered in the context of designing useful monitoring programs for determining the entrainment mortality fraction. Preliminary estimates of intake survival and the entrainment mortality fraction can be used to obtain estimates of the sample size needed for a specified level of confidence interval width or type II error. Final estimates of the intake survival and the entrainment mortality fraction can be used to determine the minimum detectable entrainment mortality and the type II error.     

Air quality assessment along Dhanbad - Jharia road

Road ambient air pollution status along Dhanbad – Jharia road isstudied and presented in this article. The selection of this areais made considering the importance of the road in Dhanbad district and the nature of activities taking place along the road, which reflect that the portion of road upto Dhansar can be considered as having commercial areas on both sides and that from Dhansar to Jharia as having industrial areas on both sides.For the assessment of the ambient air quality along the road monitoring is done at the following five locations: Indian Schoolof Mines (ISM), main gate; Bankmore; Dhansar police check post; Dhansar opencast project agent office and a residential house beside the Rajapur opencast project. The location of ISM, maingate is specially chosen as this represents a commercial shoppingcomplexes and the situation can be compared with that at Bankmore. Monitoring of ambient air quality is done following thestandard procedure prescribed in IS: 5182. In addition the concentration of lead, zinc, copper, iron, manganese, cadmium metals in SPM is also monitored. The ambient air quality is monitored in the months of September and November 1999, respectively, to represent monsoon and winter seasons. The SPM concentration observed at all the five locations in the winterseason is more than the permissible limits for commercial andindustrial areas. However, in the monsoon season, the SPM concentration is higher than the permissible limit at the twocommercial locations, i.e., ISM gate and Bankmore, while it isless than the prescribed limit for industrial areas at the remaining three locations. At the ISM gate and Bankmore the SPM generation is mainly by vehicular traffic while at other three locations it was in addition due to mining and other activities.     

Chromium removal from water by activated carbon developed from waste rubber tires

Because of the continuous production of large amount of waste tires, the disposal of waste tires represents a major environmental issue throughout the world. This paper reports the utilization of waste tires (hard-to-dispose waste) as a precursor in the production of activated carbons (pollution-cleaning adsorbent). In the preparation of activated carbon (AC), waste rubber tire (WRT) was thermally treated and activated. The tire-derived activated carbon was characterized by means of scanning electron microscope, energy-dispersive X-ray spectroscopy, FTIR spectrophotometer, and X-ray diffraction. In the IR spectrum, a number of bands centred at about 3409, 2350, 1710, 1650, and 1300–1000 cm^?1 prove the present of hydroxyl and carboxyl groups on the surface of AC in addition to C═C double bonds. The developed AC was tested and evaluated as potential adsorbent removal of chromium (III). Experimental parameters, such as contact time, initial concentration, adsorbent dosage and pH were optimized. A rapid uptake of chromium ions was observed and the equilibrium is achieved in 1 h. It was also found that the adsorption process is pH dependent. This work adds to the global discussion of the cost-effective utilization of waste rubber tires for waste water treatment.     

A comparative study on characterization of textile wastewaters (untreated and treated) toxicity by chemical and biological tests

Toxicity of textile wastewaters (untreated and treated) and their ingredient chemicals was quantified in terms of their chemical characteristics, fish (Gambusia affinis) mortality and end point growth responses of duckweed (Lemna aequinoctialis) in short-term bioassays. Other parameters of fish bioassay were erythrocyte morphology and its counts. Despite of a definite correlation between data of biological tests (LC/EC(50) values) with that of chemical tests, biological tests were found to be relatively more sensitive to both wastewaters and ingredient chemicals. Amongst all the examined parameters of test organisms, fish RBCs (morphology and counts) sensitivity to pollutants in the wastewaters was usually maximum and therefore, their study should be included in the routine fish bioassay. Other advantage of biological test such as on Lemna is even detection of eutrophic potential of wastewaters, as noted at their higher dilutions. The ingredient chemicals (major) contributing maximum toxicity to textile dye wastewater were, acids (HCl and H(2)SO(4)), alkali (Na(2)O SiO(2)), salt (NaNO(2)) and heavy metal (Cu), whereas dyes (4) were relatively less toxic.