Ahsan,N (1999): Solid waste management plan for Indian Mega-cities. Indian Journal of Environmental Protection, 19(2): 90-95.

Solid waste is now one of the major environmental problems of mega-cities. Thousands of tonnes of waste is generated every day, requiring a large land area for its disposal. An integrated solid waste management plan has been discussed including various components, for example waste minimization, material recovery, waste processing and transformation, and its disposal on land. Leachate control and gas collection at landfills have also been discussed.

Bernadette,Q; Daniel,C; Bernard,R; Thanh,TP; Gagnon,P; Benoir,F (1999): Sources and fluxes of Mercury in the St. Lawrence River. Environmental Science & Technology, 33(6): 840-849.

A mass balance approach, based essentially on the reconstruction of daily fluxes and circumscribed by strict error calculations, was designed to quantify the main mercury sources for the St. Lawrence and its tributaries, which constitute a large river system. High-frequency samplings were performed over an 18-month period (1995-1996) at the main water inputs and the mouth of the river. Minor tributaries and the Montreal effluent were also sampled This strategy allowed models to be obtained that relates mercury concentrations in solution and in particles to the hydrological regime. The calculated budget was balanced relative to the calculated errors of the estimates. Gross mercury export from the river was found to be 5.9 kmol/yr (73% as particulate). Tributaries and internal erosion of the river contributed equally for a total of 15% of this gross load, whereas the Upper St Lawrence River, which is almost exclusively composed of Lake Ontario waters, accounted for less than 10%, and inventoried anthropogenic point sources accounted for about 5%. Dissolved mercury was mainly from north shore tributaries, and particulate mercury was largely from erosion of the river bed and banks. On the basis of the present results as well as estimates of atmospheric deposition from the literature it can be inferred fat at least 88% of deposited mercury was retained in the watersheds.

Bhattacharyya,KG; Deka,DK; Sarma,C (1999): Distribution of heavy metals in surface water and bed sediments of a few drinking water sources in Guwahati. Indian Journal of Environmental Protection, 19(2): 110-118.

The study reports the distribution pattern of a few heavy metals, namely Fe, Mn, Cu, Zn, Cd, Pb, Cr, and Co in surface water and bed sediments of a few traditional drinking water sources ( 4 Ponds, 3 ring - wells and one natural reservoir ) in Guwahati City, India. The sampling and analysis were carried out on seasonal basis over a three year period. The metal contents have been found quite appreciable for both water and sediment.

Chand,D (1999): Fluoride and human health - Cause for concern. Indian Journal of Environmental Protection, 19(2): 81-89.

Intake of excess fluoride causes dental, skeletal and non-skeletal fluorosis through continued use of fluoride contaminated water, air and agricultural produce. High fluoride intake over a period of time can cripple one for life. Apart from fluorosis, it may also cause gastrointestinal complaints, namely loss of appetite, nausea, vomiting, pain in the stomach, constipation and intermittent diarrhoea and flatulence in expectant and lactating mothers, hardworking young adults, foetus and children. The adolescent age group is most vulnerable. Fluorosis has been considered as one of the incurable diseases and prevention is the only solution. At this juncture, it becomes essential to identify all possible sources of fluoride and their possible impact on health of human beings. In this paper an attempt has been made to concise the information on sources of fluoride available elsewhere in the literature.

Chatterjee,A; Mukherjee, A (1999): Hydrogeological investigation of ground water arsenic contamination in south Calcutta. Science of Total Environment, 225: 249-262.

Typical clinical symptoms of acute arsenic poisoning have been detected in 1000 residents near a factory in P.N. Mitra Lane, Behala, South Calcutta, located in a thickly populated area manufacturing copper acetoarsenite (Paris-Green) an arsenical pesticide for the past 25 years. Soil around the effluent dumping point of the factory was exceptionally contaminated, with arsenic, copper and chromium concentrations of 20100-35 500 mg/ kg, 33 900-51 100 mg/ kg and 5300-5510 mg/ kg. Arsenic and copper concentrations in bore-hole soils collected up to a depth of 24.4 m at the effluent dumping point, decreased with depth. Arsenous acid, arsenic acid, methylarsonic acid (MA) and dimethylarsinic acid (DMA) were detected in bore-hole soils up to a depth of 1.37 m, after which only inorganic arsenical compounds were present. A positive correlation was established between arsenic and copper authenticated the Paris-Green waste disposal site as the source of contamination. Mechanism of ground water contamination from this disposal site had been probed by a systematic hydrogeological survey and the arsenic content of the tube-well waters in the surrounding areas. Hydraulic conductivity was maximum in the central part. The site for disposal of the effluent was a ditch located in the zone of discharge. Sparingly soluble Paris-Green cumulatively deposited in the waste disposal site is decomposed by micro-organisms to water-soluble forms and finally percolated to underground aquifers along with rain water through the discharge zone. The contaminant is currently moving towards WNW with ground water flow and the residents in the direction of encroaching contamination are insecure due to penetration of the contaminant.