Monitoring of Cd pollution in soils and plants irrigated with untreated sewage water in some industrialized cities of Punjab, India

Abstract

The disposal of industrial and sewage water is a problem of increasing importance throughout the world. In India, and most of the developing countries untreated sewage and industrial wastes are discharged on land or into the running water streams which is used for irrigating crops. These wastes often contain high amount of trace elements which may accumulate in soils in excessive quantities on long term use and enter the food chain through absorption by the plants. Among the trace metals, Cd has received the greater attention because of its easy absorption and accumulation in plants and animals to levels toxic for their health. The objective of this study conducted in three industrially different cities viz., Ludhiana, Jalandhar and Malerkotla was to monitor the extent of Cd accumulation in soils and plants receiving untreated sewage water. Plant and soil samples were collected from sewage and tubewell irrigated areas. Soil samples were analysed for texture, pH, EC, organic carbon (OC), CaCO(3), bioavailable DTPA-Cd and plant samples were analysed for total Cd. In sewage irrigated soils, the mean values of pH were lower but organic carbon and electrical conductivity were generally higher both in surface and sub-surface layers of all the three cities as compared to tubewell irrigated soils. The mean DTPA- extractable Cd in sewage irrigated soil was 6.3- and 4.36-fold in Ludhiana, 3.38- and 1.71-fold in Jalandhar and 3.35- and 6.67-fold in Malerkotla in 0-15 and 15-30 cm soil depth, respectively, compared with the values in tubewell irrigated soils. The accumulation of DTPA-Cd in sewage irrigated soils was restricted to 30 cm depth after which the values were generally close to values in tubewell irrigated soils. Soil pH, OC, CaCO(3), clay and silt collectively accounted for 37.1%, 65.1% and 53.9% DTPA-extractable bioavailable Cd in soils of Ludhiana, Jalandhar and Malerkotla, respectively. Lower R(2) values in Ludhiana suggest that factors other than the ones mentioned may be affecting Cd availability. At all sites plants receiving sewage irrigation had elevated levels of Cd as compared to the plants receiving tubewell irrigation. The mean Cd content of sewage irrigated plants irrespective of the city was 5.96 microg g(-1) dry matter as compared to 0.98 microg g(-1) dry matter in tubewell irrigated plants. The results suggest that the intake of Cd obtained from consumption of crops grown on sewage irrigated soils would be much higher than the tolerable limits set by WHO and may, therefore, prove potentially toxic leading to various health ailments to humans and animals.

Cadmium Accumulation Characteristics in Turnip Landraces from China and Assessment of Their Phytoremediation Potential for Contaminated Soils

“…Cadmium (Cd) contamination has become the most prominent soil HM pollution issue as a result of its high toxicity, strong migration, and large pollution area globally (Moreno-Caselles et al, 2000; Wei et al, 2006). Soil Cd has three main sources including atmospheric deposition, irrigation with sewage and use of pesticides and chemical fertilizers (Sikka et al, 2009). Enrichment of Cd in soil can change soil physical and chemical properties, reduce the richness, diversity, and activity of soil microorganisms, and inhibit soil respiration, subsequently affecting soil fertility (Zheng and Shang, 2006).…”

Punjab’s Food and Water Woes:Perils of Heavy Metal Contamination

“…Some areas in Punjab are naturally endowed with heavy metals. A paper published by scientists from Punjab Agricultural University in 2009 shows that discharge from factories and industries could also add to the problem of heavy metal contamination 3 . Researchers sampled soil and crops from three cities differing in terms of industrial activity -Ludhiana, Jalandhar and Malerkotla.…”

Appraisal of pollution of potentially toxic elements in different soils collected around the industrial area

“…The town is famous for electroplating, machine tools, bicycle, woollen and dying work. The above said industries generate vast amount of sludge and industrial waste which directly discharged into Buddha Nullah tributary of Satluj river (Sikka et al, 2009). The waste reaching soil keeps on accumulating as HMs cannot be degraded or destroyed.…”