Pot experiments with soils from three contaminated sites and an additional field experiment were conducted. The aim of the experiments was to test different organic and inorganic soil amendments to heavy metal uptake and to alleviate toxicity in different agricultural crops. Elements in the extracts were measured by

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The present work describes results of pot experiments and field studies including three contaminated sites in Bangladesh. The aim was to investigate possible differences between cereal varieties ith regard to heavy metal uptake and accumulation. A total of 10 rice (Oriza sativa L.) and 3 wheat (Triticum estivum) varieties were studied. Soil samples were digested with HCl:HNO 3 (3:1), and plant

An investigation was made at Hazaribagh Tannery area, comprising about 145 industries in Dhaka Metropolitan area. The analyses of soil and plant samples showed that heavy metals contribute significantly towards environmental contamssination resulting from industrial activities. Concentration of heavy metals (Cr, Zn, Pb, Cd, Mn, Fe and Ni) in soil and plant samples cross the MAC (Maximum allowable concentration) in both wet and dry season. In case of soil sample the highest concentration of Cr (172792 ppm) was found at main disposal point. Chromium, Zn, Pb, Cd, Mn, Fe and Ni concentrations at Hazaribagh plant samples respectively ranged from 171-1348, 247-777, 45-96, 1.66-2.17, 72-231, 354-787, and 18-38 ppm respectively in dry season and 75-1142, 209-691, 29- 84, 1.02-2.00, 66-124, 331-664, 11-37 ppm respectively in wet season. Concentration went down gradually with increasing distance from the main disposal point (spot 1). But again high concentration (150708 ppm of Cr) was noted in spot 6. Similar results were found for plant samples. High concentrations of heavy metals were found in plant samples which consequently affect food chain, which may be a major environmental concern. Asiat. Soc. Bangladesh, Sci. 43(2): 207-222, December 2017

Two pot experiments were conducted at the Dept. of Soil, Water and Environment, University of Dhaka to examine the effects of Zn on red amaranth (Amaranthus sp.) and rice (Oryza sativa). The soil collected from Bhaluka, Mymensingh (Chandra series), had the following general characteristics; pH 6.0, E.C 134 μS cm-1, organic matter 2.20%, organic carbon 1.27%, total N, P, K 0.024, O.07 and 0.05 % respectively. The total Zn content was 20 ppm and the texture was silty loam. Four Zn levels were maintained by treating the experimental soils with 0, 200, 300 and 400 mg Zn/kg soil. Roots & shoots of red amaranth and rice were collected after 45 and 90 days of sowing respectively. A significant impact of zinc was observed on growth and yield of red amaranth and rice. The concentration of zinc increased with increasing zinc treatment in red amaranth and rice roots, shoots and grain. The length of roots and shoots, the fresh and dry matter production  decreased with increasing zinc levels for red amaranth. In case of Rice the length of roots, shoots and spikelets increased with increasing zinc levels and the highest was observed at 200 ppm Zn. The fresh and dry matter production at first decreased at 200 ppm Zn but increased at 300 and 400 ppm Zn for Rice. The results showed that zinc influenced the growth and yield of red amaranth and rice. Keywords: Zinc; Toxicity; Treatments; Yield; Uptake; Heavy metal.DOI: 10.3329/jbayr.v1i1.6836Journal of Bangladesh Association of Young Researchers Vol.1(1) 2011 pp.79-91

Heavy metal pollution is associated with public health concerns. The study was conducted at the vicinity of the Tejgaon industrial area (8 km 2 ) adjacent to Dhaka City Corporation. To investigate the seasonal extent of soil-water ecosystems pollution with chromium discharged from the industries, municipality, and slums, and its transfer co-efficiency into plants or crops.Composite soil, plant and water were randomly collected from industrial sites by GPS guided sampling procedure during wet and dry seasons, processed, and analyzed. Soils were analyzed for particle size distribution (sand, silt and clay), pH, electrical conductivity (EC), total organic carbon,

Aerosol particulate matter and trace gases were sampled at five locations in the city areas of Bangladesh. The sampling sites were selected in the city areas near motor vehicles run with heavy traffic. The average concentrations of total suspended particulate matter in city ambient air were 413.02, 292.63, 671.65, 184.09 and 301.13 µg m-³ in Dhaka, Noakhali, Chittagong, Faridpur and Kustia, respectively, which were higher than the daily average value, given by WHO and US EPA standard. The highest SPM concentration is in Chittagong (671.65 µg m-³) and the lowest in Faridpur (184.09 µg m-³). The city areas studied fall in the 'Unhealthy" to "Extremely Unhealthy' class according to the Air Quality Index, 2003. Trace metal concentrations of total suspended particulate matter in city ambient air were analyzed. The reported previous Pb concentration in farmgate, Dhaka was 1238 ng m -3 by Biswas et al., (2003) and now shows a decreasing tendency, presumably due to the ban on the use of leaded fuel. The average results of trace metals have been compared to national and international standards. The Cu and Zn concentration of current study is found very high in comparison with other previously reported results. The air of Chittagong city is highly polluted. Motor vehicles, especially two stroke engine vehicles are increasingly major sources of air pollution in Chittagong.

The main focus of the study is Tejgaon industrial area which is located within the Dhaka City Corporation and about 5 km north of the city centre. The industries around the study area like battery, chemical manufacturing, electrical and electronic, metal finishing, mining, paint and dye, textiles, pharmaceuticals, pesticides, etc, discharge heavy metals like Ni with their effluents and wastes. At Tejgaon soil the minimum pH value was 5.3 and the maximum 7.6 (at 26 O C). High buffering capacity resulting from high soil organic matter content (4.87-11.55%) probably influenced soil pH. Electrical conductivity (EC) (25-551 µS/cm) and organic matter (OM) (4.87-11.55%) contents were also influenced by the industrial wastes and effluents of the factories. In the wet season, the average Ni concentration in different soil fractions was 1.69, 4.16, 13.21 and 93.12 mg kg -1 in water-soluble, NH 4 OAC extractable, DTPA extractable and total fractions respectively. Comparing wet season and dry season sampling data, total Ni concentrations in different locations were higher in the dry season and the mean concentration of total Ni was 223.89 mg kg -1 , which was more than 4 times higher than the tolerable limit.Concentrations of total Ni in different locations during wet season were found above the natural background level with few exceptions. Ni concentration in the group of tolerable level was 21% (>022-<50 mg kg -1 ) and 75% (>50 mg kg -1 ) soil samples were found in the group of in excess of tolerable level during wet season. During dry season, 11% of Ni (<50 mg kg -1 ) samples were in the normal range and 89% (>50 mg kg -1 ) soil samples were found in the group of in excess of tolerable level. Ni concentration during dry season samples in different extraction i.e in NH 4 OAC extractable, DTPA extractable and in total fraction was found to decrease with distance away from the disposal point source due to dilution of the effluent and water. The decreasing tendency with distance indicates the accumulation of metals by the industrial operations.