The 27th Global COE Special Seminar titled ‘Arsenic Geochemistry and Human Issues in Asian Countries’ was held on August 19, 2010 at the Center for Marine Environmental Studies (CMES) in Ehime University, as an "Academic Seminar Series" under the Global COE program.

At the seminar, Dr. Kyoung-Woong Kim, Professor at the School of Environmental Science and Engineering, Gwangju Institute of Science and Technology in Korea introduced his studies on the risk of inorganic arsenic intake through consumption of groundwater by human in Asian countries, such as Bangladesh, Laos, Vietnam and Cambodia.

First, he has explained the toxicity of arsenic, especially inorganic forms like arsenite (III) and arsenate (V), which are more toxic than organic arsenic. The mechanism of higher toxicity of inorganic arsenic is that both trivalent and pentavalent soluble arsenic compounds are rapidly absorbed from the gastrointestinal tract and can be further metabolized. On the other hand, oral exposure pathway of organic arsenic compounds is less toxic because organic arsenicals are less extensively metabolized and more rapidly eliminated in urine than the inorganic arsenicals.

It is important to note that people living near the regions contaminated by arsenic are continuously exposed to arsenic through several pathways, such as mining, coal burning, pesticides and drinking groundwater, causing ‘Arsenocosis’. Among those pathways, the most critical one is drinking water ingestion, suggesting females may be exposed more to arsenic than males because females spend more time in their house and so use more groundwater. Arsenicosis can cause skin lesions, pigmentation of the skin, and the development of hard patches of skin on the palm of the hands and soles of the feet, which finally leads to skin, bladder, kidney, and lung cancers, as well as diseases of the blood vessels of the legs and feet.

Prof. Kim and his colleagues, therefore, have focused to develop arsenic treatment systems to remove Arsenic from groundwater by modifying the traditional sand filters. Among various treatment systems such as membrane and absorption systems, micro-filter system equipped with nano-filtration membrane showed the highest efficacy to remove almost the entire arsenic in groundwater. In order to protect people from arsenic toxicity, Prof. Kim emphasized the importance of treatment of groundwater with the micro-filter system.

After the lecture, many participants especially the members of the Association of Young Scientists had time to discuss about his research findings by asking questions and exchanging opinions with each other. Overall, this lecture provided a good opportunity for us to understand the distribution, origin, and toxicities of arsenic and the ways to protect human beings from the risk of arsenic toxicity.