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Chemical pollution arising from heavy metals and metalloids is a growing global concern and a major cause of pollution-related diseases in the world today, especially in low- and middle-income countries. The present study investigated the urinary concentrations of metals and metalloids in primary school-aged children (N = 142), living in three different industrialised areas, namely the textile, tannery, and multiple industries dominated areas of Dhaka, Bangladesh and compared with a control area. The accurate measurement of urinary concentrations of twenty-two elements was accomplished using a simple and robust ICP-MS method; hydration variations were adjusted by osmolality. Results revealed that children living in these industrialised areas were exposed to a greater extent the environmental pollutants arsenic, chromium, iron, selenium, molybdenum, tin, caesium, thallium, and lead when compared to control children, after adjusting of confounding factors such as age, sex, and nutritional status. The higher concentrations of manganese in urine (3.81 µg/L, p < 0.0001) and in drinking water samples (131.0 µg/L, p < 0.05) of the textile area, suggest an elevated risk of adverse health effects for the exposed children noting that about 70% of the drinking water samples exceeded the national recommended limit. In addition, the concentration of copper was positively correlated between drinking water and urine samples which may potentially indicate the source of exposure. This study represents the prevailing situation of metals and metalloid pollution in industrialised areas where children may be at a higher risk of heavy metal-induced health problems.

The current study is an endeavour to measure the bioaccumulation potentials of heavy metals in different parts of chilli plants (Capsicum annuum L.) grown in artificially contaminated soil with various concentrations of Cr and Pb. The concentrations of heavy metals were estimated by Atomic Absorption Spectroscopy (AAS) technique. The mean concentration of Cr and Pb accumulated in different parts of plants in high, medium, and low levels of contamination was in the following order: roots > leaves > shoots > fruits. Cr concentration in fruits was lower than that of the WHO standard. However, fruits grown on medium contaminated soil contained 0.695 mg/kg Cr which did not follow the safe guideline by SEPA. A significant amount of Pb was traced in fruits grown in highly contaminated soil that exceeded the standard limit set by FAO/WHO. Accumulation of Pb was higher than Cr at different levels of contamination in every part of the chilli plants. The transfer factor for Cr and Pd was found in the following order, leaves > shoots > fruits> roots and leaves > shoots > roots > fruits, correspondingly at every level of contamination. The bioconcentration factors were higher in Pb than Cr. The daily intake of metals in combination with health and carcinogenic risk indexes indicated that the edible parts of chilli plants are safe to consume as recommended by SEPA/WHO/FAO. The present study can be considered a reference for assessment and monitoring of heavy metals associated with human health risks in chilli plants at different industrially contaminated sites.

In the present investigation, five novel Cr(VI) reducing bacteria were isolated from tannery effluents and solid wastes and identified as Kosakonia cowanii MKPF2, Klebsiella pneumonia MKPF5, Acinetobacter gerneri MKPF7, Klebsiella variicola MKPF8 and Serratia marcescens MKPF12 by 16S rDNA gene sequence analysis. The maximum tolerance concentration of Cr(VI) as K2Cr2O7 of the bacterial isolates was varying up to 2000 mg/L. Among the investigated bacterial isolates, A. gerneri MKPF7 was best in terms of reduction rate. The optimum temperatures for growth and Cr(VI) reduction by the bacterial isolates were 35 and 40 °C, respectively except A. gerneri MKPF7 which grew and reduced Cr(VI) optimally at 40 °C. The optimum pH for growth and Cr(VI) reduction by K. cowanii MKPF2, A. gerneri MKPF7 and S. marcescens MKPF12 was 7.0 whereas the optimum pH for growth and Cr(VI) reduction by K. pneumoniae MKPF5 and K. variicola MKPF8 were 7.0, 8.0 and 6.0, 7.0, respectively. All the bacterial isolates showed maximum tolerance against Ni2+ and Zn2+ whereas minimum tolerance was observed against Hg2+ and Cd2+. The bacteria isolated in the present study thus can be used as eco-friendly biological expedients for the remediation and detoxification of Cr(VI) from the contaminated environments.

Accumulation of heavy metals in environmental matrices is a potential risk to living system due to their uptake by plants and subsequent introduction into the food chain. A study was conducted to investigate the heavy metals concentration in soils and leafy vegetables samples along the Dhaka Aricha Road to assess their potential ecological risk. Heavy metals concentration was analyzed by Atomic Absorption Spectroscopy. Concentrations ofallthetestedheavy metals except Cd in soil samples were below the permissible level. The mean concentration of Cd was found 3.99 +/- 1.85 mg kg(-1). Concentrations of all the tested heavy metals except Cd and Cr in vegetables samples were lower than recommended level. Mean concentration of Cd and Cr were found 1.00 +/- 0.68 mg kg(-1) and 2.32 +/- 0.84 mg kg(-1), respectively. Based on the Potential Ecological Risk Index, Cd posed very high risk to the local ecosystem due to its higher Risk Factor, > 320 and based on Transfer Factor of Pb and Cd were found higher accumulator among the tested metals. The results of present study revealed that the bioconcentration of heavy metals along the Dhaka Aricha Road posed high risk to the ecosystem. Considering the Transfer Factor of Cd and Pb it can be suggested that plants and leafy vegetables grow in the soil near Dhaka Aricha Road should not be used as food or feed.

The giant fresh water prawn, Macrobrachium rosenbergii (de Man), a leading export item of Bangladesh was studied in terms of pathogenic bacteria, pesticide residues and metal contents. In microbiological analysis, total viable bacteria, total coliform, total faecal coliform, total Salmonella and total Vibrio count were ranged from 6.8 × 10 4 to 1.6 × 10 6 , 1.5 × 10 2 to 1.8 × 10 5 , 0.0 to 5.0 × 10 2 , 0.0 to 1.8 × 10 2 and 0.0 to 3.6 × 10 2 cfu/gm, respectively. Pesticide residue was analyzed by HPLC. Out of six samples studied, one was found to be contaminated with Quinalphos and another with Cypermethrin, where the concentrations were 0.03 and 0.56 ppm, respectively, below the maximum residue limit set by joint FAO/WHO expert committee. Copper (Cu), cadmium (Cd) and lead (Pb) concentrations were measured by atomic absorption spectrophotometer. The range found for Cu and Cd was from 0.01 to 0.11 ppm and 0.01 to 0.06 ppm, respectively, which is below the maximum residue limit set by joint FAO/WHO expert committee (10 ppm for Cu and 0.2 ppm for Cd). Relatively high microbial load and presence of pathogens in all the tested samples, collected from local market revealed that the samples had exposure to an unhealthy environment. DOI: http://dx.doi.org/10.3329/jbas.v35i1.7974 Journal of Bangladesh Academy of Sciences, Vol.35, No.1, 91-97, 2011

The present study was undertaken to determine the content of six minerals, five trace elements, and ten pesticide residues in honeys originating from different regions of Malaysia. Calcium (Ca), magnesium (Mg), iron (Fe), and zinc (Zn) were analyzed by flame atomic absorption spectrometry (FAAS), while sodium (Na) and potassium (K) were analyzed by flame emission spectrometry (FAES). Trace elements such as arsenic (As), lead (Pb), cadmium (Cd), copper (Cu), and cobalt (Co) were analyzed by graphite furnace atomic absorption spectrometry (GFAAS) following the microwave digestion of honey. High mineral contents were observed in the investigated honeys with K, Na, Ca, and Fe being the most abundant elements (mean concentrations of 1349.34, 236.80, 183.67, and 162.31 mg/kg, resp.). The concentrations of the trace elements were within the recommended limits, indicating that the honeys were of good quality. Principal component analysis reveals good discrimination between the different honey samples. The pesticide analysis for the presence of organophosphorus and carbamates was performed by high performance liquid chromatography (HPLC). No pesticide residues were detected in any of the investigated honey samples, indicating that the honeys were pure. Our study reveals that Malaysian honeys are rich sources of minerals with trace elements present within permissible limits and that they are free from pesticide contamination.

Background: Cow milk is considered as one of the responsible food sources contaminated with heavy metals. The objectives of the study were to assess the content of selected metals in cow milk and its associated human health risks in the food chain of Bangladesh. A total of 90 cow milk samples of Branded, Dairy and Domestically produced milk were collected randomly from different sources of Savar Upazila in Dhaka area. Cadmium (Cd), chromium (Cr), lead (Pb), manganese (Mn), copper (Cu) and iron (Fe) contents in collected milk samples were determined using Flame Atomic Absorption Spectrometry (FAAS). To ensure quality control, one of the best quality control parameters i.e. recovery test; from eight various sample digestion methods were used. The Hazard Quotient (HQ) and Carcinogenic Risk (CR) values were also calculated. Results: From the results, it was found that, the orders of heavy metal content in brand, dairy and domestic cow milk were Cr > Fe > Cu>Mn > Cd > Pb, Cr > Fe > Mn > Cu > Cd > Pb and Fe > Cr > Mn > Cu > Cd > Pb, respectively. Among the six metals, only Cr showed to exceed the highest Estimated Daily Intake (EDI) rate (for brand cow milk: 0.413 mg/day, dairy farm cow milk: 0.243 mg/day, domestic cow milk: 0. 352 mg/day),and the comparison percentages of calculated values per permeable values were as follows; 206.5 % for brand cow milk,121.5 % for dairy farm cow milk and 176.0 % for domestic cow milk. Hazard Quotients (HQ) values and Carcinogenic Risk (CR) values were found within the acceptable level. Conclusion: Although, the metal content in sampled cow milks were within the safe limit, the potential human health risks cannot be neglected for the regular/long time consumption of heavy metal contained cow milk.