Contribution of water and cooked rice to an estimation of the dietary intake of inorganic arsenic in a rural village of West Bengal,India

Arsenic contamination of rice plants by arsenic-polluted irrigation groundwater could result in high arsenic concentrations in cooked rice. The main objective of the study was to estimate the total and inorganic arsenic intakes in a rural population of West Bengal, India, through both drinking water and cooked rice. Simulated cooking of rice with different levels of arsenic species in the cooking water was carried out. The presence of arsenic in the cooking water was provided by four arsenic species (arsenite, arsenate, methylarsonate or dimethylarsinate) and at three total arsenic concentrations (50,?250 or 500?µg?l^?1). The results show that the arsenic concentration in cooked rice is always higher than that in raw rice and range from 227 to 1642?µg?kg^?1. The cooking process did not change the arsenic speciation in rice. Cooked rice contributed a mean of 41% to the daily intake of inorganic arsenic. The daily inorganic arsenic intakes for water plus rice were 229, 1024 and 2000?µg?day^?1 for initial arsenic concentrations in the cooking water of 50, 250 and 500?µg?arsenic?l^?1, respectively, compared with the tolerable daily intake which is 150?µg?day^?1.     

Tilt Estimation in Moderate-to-Strong Scintillation

Adaptive optics systems are being applied in ever more challenging environments, for example, the projection of lasers over long horizontal paths through the atmosphere. These long atmospheric paths corrupt the signal received from the beacon and typically yield highly scintillated received wave fronts. Tilt estimation for controlling the fast steering mirror in these systems is complicated by the presence of branch points in the scintillated received wave fronts. In particular, correlation between the tilt and the projected beam's centroid error at the target has been observed in horizontal laser beam projection experiments. The presence of this correlation indicates that better tracking performance should be achievable. We compare the performance of four estimation schemes applied to tilt estimation in a horizontal laser projection system. It is demonstrated that all four schemes underestimate the tilt required to return the laser beam to a target in highly scintillated environments. A method of correcting this tilt is presented, and the expected performance improvement is quantified.     

Evidence of PAH production under lean combustion conditions

While it is common knowledge that PAH formation can be expected at rich combustion conditions, this paper presents experimental and computational evidence that PAH formation can also be expected under lean, or cool, combustion conditions. Experimental evidence for diesel engine operation at lean conditions, as well as the literature references related to waste tire and coal combustion, are cited as supportive evidence of conclusions drawn here. A computational model based on reaction mechanisms for three surrogate fuels: C₂H₂, C₇H₁₆ and C₁₄H₂₈, was validated against the available diesel engine data, and projected to both lean and rich combustion conditions. The finding was that for the adiabatic case, minimum production of PAHs occurs at equivalence of unity and increases as equivalence becomes either lean or rich; the latter observation being consistent with the common knowledge.     

Simplified Inelastic Design of Steel Girder Bridges

Inelastic design of steel girder bridges can result in beneficial material and fabrication cost savings and reduce the susceptibility of steel girder bridges to fatigue. The ability to redistribute large negative region moments, coupled with section capacities exceeding the yield moment, results in an efficient structure used to its limit-state capacity. Proposed LRFD inelastic design provisions are presented that allow compact or noncompact pier sections resulting in consistent bridge design across the steel girder bridge inventory. This paper illustrates the simplified inelastic design provisions, presents an example design of a two-span composite bridge comprising noncompact sections at the pier, and summarizes the experimental verification of the example design. The proposed inelastic design procedures are simple to apply, removing the cumbersome continuity and iterative requirements of past inelastic design practice.     

Contribution of water and cooked rice to an estimation of the dietary intake of inorganic arsenic in a rural village of West Bengal, India

Arsenic contamination of rice plants by arsenic-polluted irrigation groundwater could result in high arsenic concentrations in cooked rice. The main objective of the study was to estimate the total and inorganic arsenic intakes in a rural population of West Bengal, India, through both drinking water and cooked rice. Simulated cooking of rice with different levels of arsenic species in the cooking water was carried out. The presence of arsenic in the cooking water was provided by four arsenic species (arsenite, arsenate, methylarsonate or dimethylarsinate) and at three total arsenic concentrations (50, 250 or 500 µg l^-1). The results show that the arsenic concentration in cooked rice is always higher than that in raw rice and range from 227 to 1642 µg kg^-1. The cooking process did not change the arsenic speciation in rice. Cooked rice contributed a mean of 41% to the daily intake of inorganic arsenic. The daily inorganic arsenic intakes for water plus rice were 229, 1024 and 2000 µg day^-1 for initial arsenic concentrations in the cooking water of 50, 250 and 500 µg arsenic l^-1, respectively, compared with the tolerable daily intake which is 150 µg day^-1.     

7th International Conference on Acid Rock Drainage (ICARD)

2006 Call for Participation

7^th International Conference on Acid Rock Drainage (ICARD) in Conjunction with SME Annual Meeting and Exhibit, St. Louis Missouri March 27—30, 2006     

Chromosome aberrations induced in human lymphocytes by heavy charged particles in track segment mode

Human blood was irradiated with accelerated ions: 20 MeV 4He, 425 MeV 12C and 1480 MeV and 996 MeV 16O. For each ion, the blood was exposed to a range of doses as thin specimens in the track segment mode, so that irradiations took place at nearly constant LETs of 31.4, 61, 52 and 69 keV microm(-1), respectively. Lymphocytes were cultured to the first in vitro metaphase, analysed for chromosomal damage and the dicentric aberration frequencies fitted to the linear quadratic model of dose-response. For these high LET radiations, the linear (alpha) yield coefficient predominated and increased with LET, at least up to 60 keV microm(-1). Apart from the 996 MeV oxygen ions, the data indicated the presence of a quadratic (beta) coefficient, statistically consistent with values obtained with low LET radiations. However, the associated uncertainties on the measured beta values were large, illustrating the general problem that beta is more difficult to measure against a dominating and ever-increasing alpha term. The existence or otherwise of a beta component of the dose-response at these radiation qualities has important consequences for modelling mechanisms of aberration induction by radiation.     

Nonlinear correlation for estimating the motion of multiple objects in image sequences

A nonlinear correlation algorithm is proposed for estimating the motion of objects from an image pair. This algorithm requires no a priori information on the number, size, or shape of the moving objects and does not require feature extraction or segmentation of either image. The algorithm directly yields information on the number of moving objects, the motion of the objects, and the size of the objects. Additional processing can be performed to yield the centroid of the objects in either frame. The utility of the resulting algorithm is demonstrated by application to a pair of example image sequences.     

Inorganic and Total Arsenic Contents in Rice and Rice‐Based Foods Consumed by a Potential Risk Subpopulation: Sportspeople

One of the main routes of exposure to inorganic arsenic (i‐As) in humans is food, especially rice and rice‐based products. There are certain groups of consumers that could be highly exposed to i‐As. Maximum levels of i‐As have been issued for infants and young children by the European Union, but perhaps other groups are also at risk. Sportspeople could be one of those groups, due to their specific nutritional requirements, especially its high consumption of cereals, such as rice. Because of the well‐known relationship between rice and i‐As, the intake of i‐As by sportspeople deserved especial attention and was estimated in Spain. This study demonstrated that rice‐based products reached a maximum i‐As content of 178 μg/kg, with a mean for all studied products of 56 μg/kg; the maximum contents were found in rice cakes (149 μg/kg) and brown rice (111 μg/kg). The estimated daily intake of i‐As were 0.16 and 0.18 μg/kg bw (body weight)/d, in sportsmen and sportswomen, respectively. These values were below the BMDL₀₁, 0.3 to 8.0 μg/kg bw/d; thus, it can be concluded that the sportspeople group is not at a significant risk regarding the intake of i‐As. However, further studies are needed to evaluate their whole diet and not only rice‐based products. Finally, it is important to claim that companies producing rice products include as much information as possible about the rice used in their products, including rice percentage and geographical origin.     

Mathematical quantification of total carotenoids in Sioma<Superscript>®</Superscript> oil using color coordinates and multiple linear regression during deep-frying simulations

Sioma^® is a variety of red palm oil produced in Ecuador; it is mainly unsaturated, has no flavor, odor, nor cholesterol, and it is GMO-free and free of trans fatty acids. The main objectives of this study were: (a) to study changes in fatty acids, color coordinates, total carotenoids and carotenoid composition during deep-frying simulations; (b) to develop a mathematical model that allows quantification of total carotenoids (antioxidant compounds) using routine color measurements. Two different deep-frying temperatures were assayed 180 and 240 °C. The main fatty acids and carotenoids found in this oil were: (a) oleic, palmitic, and linoleic acids, and (b) α-, β-, and δ-carotenes. During these deep-frying simulations, Sioma^® oil became lighter and more yellowish (L* and b* values increased) and more greenish (a* values decreased); these changes were more evident for higher temperatures. At 180 °C, total carotenoids decreased linearly, from almost 500 mg L^?1, at a rate of 5 mg /kg¹ min^?1; however, at 240 °C the degradation of carotenoids was almost complete after 40 min. Finally, the mathematical models developed using multiple linear regressions allowed an easy and fast quantification of total carotenoids using color measurements.