Ecosystem aspects of arsenic poisoning: Human exposure to arsenic from food chain

Although the main source of arsenic to human body is ground water, the use of arsenic contaminated ground water for irrigation gives rise to the question whether arsenic uptake in crop plants could also be another potential pathway of human exposure to arsenic. Arsenic content in straw, grain and husk of rice is especially important as rice is the staple food for man and straw and husk have been used as cattle feed. It was estimated that the daily intake of arsenic in human body from rice (containing 0.40 mg As/kg, the highest concentration of arsenic found in the present experiment in treatment containing 40 mg As/kg soil) is 0.20 to 0.32 mg/day (as the average consumption of rice by the people above five years old is between 400 and 650 gm/day) whereas it is 0.20 mg/day from drinking water (as the recommended safe level arsenic in drinking water is 0.05 mg As/l for Bangladesh and the average intake of water by an adult is about four litres). This finding suggests that arsenic intake in human body through rice could be a potential pathway in addition to drinking water. Therefore, a hypothesis have been put forward that the human beings have not been suffering from arsenicosis only from drinking water but also from "Plant-Animal-Man" and some other food chain pathway

Straighthead disease of rice (Oryza sativa L.) induced by arsenic toxicity

Straighthead disease is a physiological disorder of rice (Oryza sativa L.) characterized by sterility of the florates/spikelets leading to reduced grain yield. Though the exact cause of straighthead is unknown, a glass house experiment was conducted to investigate the effect of inorganic arsenic on straighthead disease in rice (Oryza sativa L.). BRRI dhan 29, a popular Bangladeshi rice strain, was grown in soils spiked with arsenic (prepared from sodium arsenate, Na2HAsO4·7H2O) at the rate of 10, 20, 30, 40, 50, 60, 70, 80 and 90 mg of As kg-1 and one control treatment was also run to compare the results. Although there may be some other soil physico-chemical factors involved, arsenic concentration was found to be closely associated with straighthead of rice. With the increase of soil arsenic concentration, the severity of straighthead increased significantly. Up to the 50 mg of As kg-1 soil treatments, the severity of straighthead incidences were not prevalent. Straighthead resulted in sterile florets with distorted lemma and palea, reduced plant height, tillering, panicle length and grain yield. Straighthead caused approximately 17-100% sterile florates/spikelets formation and about 16-100% loss of grain yield. Straighthead also causes the reduction of panicle formation and panicle length significantly (p < 0.01). In the present study, panicle formation was found to be reduced by 21-95% by straighthead. © 2007 Elsevier B.V. All rights reserved

Arsenic accumulation in rice (Oryza sativa L.) varieties of Bangladesh: A glass house study

A glass house study was conducted to investigate the accumulation of arsenic in tissues of five widely cultivated rice (Oryza sativa L.) varieties of Bangladesh namely BRRI dhan 28, BRRI dhan 29, BRRI dhan 35, BRRI dhan 36, BRRI hybrid dhan 1. Arsenic concentrations were measured in straw, husk and brown and polish rice grain to see the differential accumulation of arsenic among the rice varieties. The results showed that the concentrations of arsenic in different parts of all rice varieties increased significantly (p BRRI dhan 35 > BRRI dhan 36 > BRRI dhan 29 > BRRI hybrid dhan 1. The order of arsenic contents in tissues of rice was: straw > husk > brown rice grain > polish rice grain. © 2007 Springer Science+Business Media B.V

Arsenic accumulation in rice (Oryza sativa L.): Human exposure through food chain

Although human exposure to arsenic is thought to be caused mainly through arsenic-contaminated underground drinking water, the use of this water for irrigation enhances the possibility of arsenic uptake into crop plants. Rice is the staple food grain in Bangladesh. Arsenic content in straw, grain and husk of rice is especially important since paddy fields are extensively irrigated with underground water having high level of arsenic concentration. However, straw and husk are widely used as cattle feed. Arsenic concentration in rice grain was 0.5±0.02 mg kg-1 with the highest concentrations being in grains grown on soil treated with 40 mg As kg-1 soil. With the average rice consumption between 400 and 650 g/day by typical adults in the arsenic-affected areas of Bangladesh, the intake of arsenic through rice stood at 0.20-0.35 mg/day. With a daily consumption of 4 L drinking water, arsenic intake through drinking water stands at 0.2 mg/day. Moreover, when the rice plant was grown in 60 mg of As kg-1 soil, arsenic concentrations in rice straw were 20.6±0.52 at panicle initiation stage and 23.7±0.44 at maturity stage, whereas it was 1.6±0.20 mg kg-1 in husk. Cattle drink a considerable amount of water. So alike human beings, arsenic gets deposited into cattle body through rice straw and husk as well as from drinking water which in turn finds a route into the human body. Arsenic intake in human body from rice and cattle could be potentially important and it exists in addition to that from drinking water. Therefore, a hypothesis has been put forward elucidating the possible food chain pathways through which arsenic may enter into human body. © 2007 Elsevier Inc. All rights reserved

Characterization of inter-seasonal climatic variability through dry-season rice productivity in the north-west region of Bangladesh

Inter-annual climatic variability in Bangladesh is significant and the probability of occurrence of extreme episodic/ climatic events has increased in the last couple of decades and thus threatening food security. Impact of inter-seasonal climatic va riability on Boro rice (dry season) yield in north-western parts of Bangladesh was analyzed using the historic weather datasets for 1971 to 2010 and MAKESENS model. Boro rice yield increased from 1980 onwards and the growth rate picked up with time. Inter-annual and inter-seasonal climatic variability was noticed through maximum and minimum temperatures, rainfall and sunshine hours. In general, temperatures and rainfall showed increasing trends but sunshine hours were decreasing gradually during the study period. Growth rates in average annual maximum, minimum and mean air temperatures were 0.001, 0.016 and 0.009°C year-1, respectively. On regional scale, Boro-rice seasonal maximum temperature was decreasing by 0.013°C year-1 but minimum and mean temperatures were increasing by 0.024 and 0.006°C year-1, respectively. Annual average sunshine hours in the study location were in decreasing trend by 0.027 hr year-1, but reduction in seasonal sunshine hours was 0.035 hr year-1. Inter-seasonal climatic variability was characterized through the Boro-rice yields in four test regions of north-west region of Bangladesh. Trend line equations were evolved for assessing the impact of climatic variations on Bororice yield. If maximum temperature changes by 1oC, Boro rice yield could be increased by 0.13 t ha-1, but it would reduce by 0.34 t ha-1 with one degree rise in minimum temperature. If sunshine hour decreases by 1 hr, Boro rice yield would decrease by 0.70 t ha-1 in study locations. Combined effects of maximum and minimum temperatures and sunshine hours showed significant influence on grain yields of Boro rice. These imply that temperature tolerant and solar radiation use-efficient rice varieties need to be bred for combating climate change impact in Bangladesh. There is a need to identify optimum sowing/transplanting window for the region, choice of suitable cultivars/ideo-types, and adoption of appropriate water and nutrients management strategies and adoption of appropriate resource conservation technologies for sustainable Boro rice production in Bangladesh

Effect of arsenic on photosynthesis, growth and yield of five widely cultivated rice (Oryza sativa L.) varieties in Bangladesh

A glass house experiment was conducted to investigate the effect of soil arsenic on photosynthetic pigments, chlorophyll-a and -b, and their correlations with rice yield and growth. The experiment was designed with three replications of six arsenic treatments viz. control, 10, 20, 30, 60, 90 mg of As kg-1 soil. Arsenic concentration in initial soil, to which the above mentioned concentrations of arsenic were added, was 6.44 ± 0.24 mg kg-1. Both chlorophyll-a and -b contents in rice leaf decreased significantly (p 0.05) from each other in control treatment though they differed significantly (p < 0.05) from each other in 30 mg of As kg-1 soil treatment. Among the five rice varieties, chlorophyll content in BRRI dhan 35 was found to be mostly affected with the increase of soil arsenic concentration while BRRI hybrid dhan 1 was least affected. Well correlations were observed between chlorophyll content and rice growth and yield suggesting that arsenic toxicity affects the photosynthesis which ultimately results in the reduction of rice growth and yield. © 2006 Elsevier Ltd. All rights reserved

Nanoethics, science communication, and a fourth model for public engagement

This paper develops a fourth model of public engagement with science, grounded in the principle of nurturing scientific agency through online participatory bioethics. It argues that social media is an effective device through which to enable such engagement, as it has the capacity to empower users and transforms audiences into co-producers of knowledge, rather than consumers of content, the value of which is recognised within the citizen science movement. Social media also fosters greater engagement with the political and legal implications of science, thus promoting the value of scientific citizenship through the acquisition of science capital. This argument is explored by considering the case of nanoscience and nanotechnology, as an exemplar for how emerging technologies may be handled by the scientific community and science policy makers, and as a technology that has defined a second era of science communication

Assessing inconsistency in global land cover products and a synthesis of studies on land use and land cover dynamics during 2001-2017 in the southeastern region of Bangladesh

The high-quality Land Use and Land Cover data is important for monitoring and analyzing environmental changes in the background of global warming. This study accessed the spatial and areal inconsistencies in the four most recent multi-resources land cover products in a complex manner using the common classification systems of IGBP-17, IGBP-9, IPCC-5 and TC (vegetation, wetlands and others only). Based on inconsistencies and multi temporal land cover datasets, a synthesis of study was triggered out on land use and land cover dynamics during 2001-2017 in the southeastern region of Bangladesh. The overall areal and spatial inconsistencies decreased from high to low levels of aggregation (IGBP-17 to TC), indicating that the inconsistencies are not only influenced by the level of thematic detail and landscape complexity but also related to the conversion uncertainties. Overall areal inconsistency in the comparison of the FROM-GLC and GlobeLand30 datasets was the smallest among the six pairs, while, the pair of MODISLC and LULC was observed the highest inconsistencies. Based on overall lower inconsistencies classification system (IGBP-9), the synthetic land use cover changes at the study area were assessed. During the period of study, the areal distribution of forest cover, built-up areas and water were found increased in annually by 0.4%, 1.32%, and 0.3% respectively, while the croplands and wetlands were respectively decreased by 0.5% and 0.3%. The dynamic changes of croplands, forest, and artificial surface were identified the prime cyclic land cover change. This research is helpful in providing training areas for the producer of land cover products

Personality Traits of Substance Users in Bangladesh

Background: Drug taking behavior and drug dependence is a multi-factorial disorder. Personality is a very important determining factor of drug dependence. Objectives: To find out the possible relationship between personality traits and substance use disorders. Methods: This was a descriptive, cross-sectional and case-control study conducted in the department of Psychiatry of Bangabandhu Sheikh Mujib Medical University and Central Drug Addiction Treatment Center, Dhaka for a period of one year (January 2005 to December 2005). From five hundred respondents, 250 had the history of substance use disorders selected as case, and equal number were age, sex, habitat and economic background matched controls were taken. Personality traits of both cases and control were measured by applying Eysenck Personality Questionnaire. Results: Mean &plusmn; SD psychoticism (8.42&plusmn;3 vs 4.33&plusmn;1.8), Neuroticism (11.89&plusmn;2.3 vs 9.83&plusmn;2) were significantly higher (P&lt;0.01) in cases than controls. It was found that psychoticism was 2.3 times and neurticism was 1.7 times higher in substance users than that of controls. There were no significant differences of mean distribution of extroversion and lie scales among the cases &amp; controls. This study also revealed that, there was no significant relationship between personality traits and different variables related to substance use except that psychoticism was significantly higher in those substance users who had have positive history of troubles with law than those having no history of trouble with law (8.82&plusmn;3.2 &amp; 7.95&plusmn;2.7 respectively). Conclusion: Personality traits may have an influence on persons with substance use disorder which detoriates quality of life. Key words: Drug dependence; Personality; Psychoticism; Neuroticism; Extraversion; Lie scale. DOI: 10.3329/bsmmuj.v3i2.7056BSMMU J 2010; 3(2): 76-8

Personality Traits of Substance Users in Bangladesh

Background: Drug taking behavior and drug dependence is a multi-factorial disorder. Personality is a very important determining factor of drug dependence. Objectives: To find out the possible relationship between personality traits and substance use disorders. Methods: This was a descriptive, cross-sectional and case-control study conducted in the department of Psychiatry of Bangabandhu Sheikh Mujib Medical University and Central Drug Addiction Treatment Center, Dhaka for a period of one year (January 2005 to December 2005). From five hundred respondents, 250 had the history of substance use disorders selected as case, and equal number were age, sex, habitat and economic background matched controls were taken. Personality traits of both cases and control were measured by applying Eysenck Personality Questionnaire. Results: Mean &plusmn; SD psychoticism (8.42&plusmn;3 vs 4.33&plusmn;1.8), Neuroticism (11.89&plusmn;2.3 vs 9.83&plusmn;2) were significantly higher (P&lt;0.01) in cases than controls. It was found that psychoticism was 2.3 times and neurticism was 1.7 times higher in substance users than that of controls. There were no significant differences of mean distribution of extroversion and lie scales among the cases &amp; controls. This study also revealed that, there was no significant relationship between personality traits and different variables related to substance use except that psychoticism was significantly higher in those substance users who had have positive history of troubles with law than those having no history of trouble with law (8.82&plusmn;3.2 &amp; 7.95&plusmn;2.7 respectively). Conclusion: Personality traits may have an influence on persons with substance use disorder which detoriates quality of life. Key words: Drug dependence; Personality; Psychoticism; Neuroticism; Extraversion; Lie scale. DOI: 10.3329/bsmmuj.v3i2.7056BSMMU J 2010; 3(2): 76-8