Wednesday, September 26, 2007

Take My Handkerchief

Bengali lessons are coming along slowly. I've completed about 10 units, and have gotten comfortable reading and writing a little more than half of the letters. However, the emphasis isn't on building vocab just yet, so the only things that I can consistently remember how to say are:

Amar nam Alicia. (My name is Alicia.)

Aam anun. (Bring [some] mangoes.)


Amar rumal nin. (Take my handkerchief.)

Useful phrases--these will make for some interesting, albeit brief, conversations...

Sunday, September 23, 2007

Previous Research Foci

Thus far, arsenic research has had three primary focal points: geological, engineering, and biomedical. Geological research has placed emphasis on monitoring arsenic levels in the groundwater, and determining the geological sources of the Bangladeshi groundwater contamination. Arsenic present in the alluvial Ganges aquifers originates in Himalayan catchments (Hossain, Bagtzoglou, Nahar, & Hossain, 2006). Dissolved arsenic is present most prominently at shallow levels (<150 m), and tend to be associated with Middle Holocene aquifers (Shamsudduha & Uddin, 2006). According to Hossain et al. (2006), spatial patterns of arsenic contamination exist in rural areas. In light of this information, it has been suggested that priority areas be established for water testing and remedial action. Other studies indicated an inverse relationship between topographical level and groundwater arsenic concentrations (Shamsudduha & Uddin, 2006). Researchers have also noted seasonal patterns of arsenic concentration fluctuation in agricultural soils. There is a noted increase of soil-arsenic content after irrigation of crops in the drier growing seasons, followed by a decline brought about by the wet season (Harvey, Swartz, Badruzzaman, Keon-Blute, Yu, Ali et al., 2005; Saha & Ali, 2007). In this manner, accumulation of arsenic in topsoil is found to be counteracted by natural geological processes.

Engineering efforts have emphasized the development of safe-water solutions, advocating the installation of deeper wells, the treatment of standing water sources, and the harvesting of rain water. It was found that when arsenic-removal techniques were implemented, disposal of arsenic waste was an issue of concern—if not handled properly, such arsenic could ultimately return to the local groundwater systems (Jakariya, Rahman, Chowdhury, Rahman, Yunus, Bhiuya et al., 2005). Other studies have reported the successful establishment of water renewal/ recycling centers that serve to treat contaminated water by means of ferric oxyhydroxide adsorption, and to store wastes safely (Anstiss, Ahmed, Islam, Khan, & Arewgoda, 2001; Mohan & Pittman, 2007). Pilot studies in other areas have led some researchers to believe the most cost-effective and community-friendly option would be the installation of cluster-based piped water systems (Hoque, Hoque, Ahmed, Islam, Azad, Ali et al., 2004).

Biomedical research has offered discussions of the effects of arsenic on the body and the potential for treatment alternatives. Blood arsenic content has recently been identified as a reliable biomarker of arsenic exposure (in addition to urine, hair, and nail arsenic content) and risk of skin lesion development (Ahamed, Sengupta, Mukherjee, Hossain, Das, Nayak et al., 2006; Hall, Chen, Ahsan, Slavkovich, van Geen, Parvez et al., 2006). Arsenic exposure has been found to elicit chromosomal aberrations (CA) and decreased chromosomal repair, both contributing to its carcinogenic effects (Andrew, Burgess, Meza, Demidenko, Waugh, Hamilton et al., 2006; Mahata, Basu, Ghoshal, Sarkar, Roy, Poddar et al., 2003). Other investigations have shown arsenic to have a diabetogenic effect (Rahman, Tondel, Ahmad, & Axelson, 1998; Tseng, 2004). Arsenic has also been found to disrupt several types of hormone receptors, enabling it to affect multiple body systems (McDavid & Hawkins, 2007).

Considerable research has been conducted to examine the relationship between arsenicosis and nutrition. Early studies noted a correlation between poor nutritional status and arsenic exposure, yet did not explain particular causal relationships (Milton et al., 2004). A later study suggested that arsenic exposure does, in fact, result in poorer nutritional status, especially in children (Minamoto, Mascie-Taylor, Moji, Karim, & Rahman, 2005).

Researchers in China have also suggested an association between arsenic exposure and mental health problems (Fujino, Guo, Liu, You, Miyatake, & Yoshimura, 2004). Moreover, arsenicosis has been associated with reduced intellectual function in children, and overall neurologic effects in adults (Wasserman, Liu, Parvez, Ahsan, Factor-Litvak, van Geen et al., 2004)

Additional studies have shown that co-exposure to arsenic and anilofos (a crop protection agent commonly used in Bangladesh) yields additive toxic effects in rat embryofetal development (Aggarwal, Wangikar, Sarkar, Rao, Kumar, Dwivedi et al., 2007). Similarly, arsenicosis in mice leads to liver apoptosis (Santra, Chowdhury, Ghatak, Biswas, & Dhali, 2007).

NOTE: If you would like full bibliographic information for any of the above citations, please let me know.