No abstract

The association of many environmentally sensitive chemicals and their transformation products with mineral and organic substrates is of considerable importance for environmental monitoring, prediction and management purposes in rivers and their basins . Our understanding of these relationships is poor . This paper reviews processes of particular concern, including the physical behaviour of fine-grained (< 63 µm) sediment in freshwater ; the role of flocculation as a transport vector ; the processes that control freshwater flocculation including microbiological factors ; the uncertainty in conventional sediment transport models for predicting pathways of sediment-associated chemistry ; the relationship between suspended sediment and toxicity in the water column ; and the partitioning of chemicals between the sediment, organic and water phase, including the significance of these in predicting chemical transport on suspended matter . 177

Occupational dermatoses are common in paddy field workers.

No abstract

The north eastern part of Anantapur district is in the state of Andhra Pradesh, India, is significant as it is covered by varied geological formations and has different land use and irrigation practices. Though ground water is the major drinking water source, deterioration in its quality is going unchecked. In such agro-economy based rural areas, the nitrate contamination is rampant and much attention has not been drawn towards this anthropogenic pollution. In the study area ground water samples from different hydrogeological set-up have been collected during the pre and post monsoon seasons and analysed for the major ions such as Ca, Mg, Na, K, CO(3), HCO(3), Cl, SO(4), NO(3) and F. The study revealed that 65% of the samples were found to be unsuitable for drinking purposes in the pre monsoon season and 45% in the post monsoon due to excess nitrate (>45 mg/l) content in the ground water. Among the different seasons and environs, nitrate was in highest concentration in the granitic terrain and canal command areas during pre monsoon season. The nitrate was found to decrease with depth in all the hydrogeological set-ups in both the seasons. Intense agriculture practices, improper sewerage and organic waste disposal methods were observed to contribute nitrate to the shallow and moderately deep aquifers.