PhD Student: Nguyen Thanh Gia

Supervisors: Prof.Toru Watanabe

International University: Yamagata university, Japan

            Health risk due to food contamination induced by urban flood - PhD student Nguyen Thanh Gia

             Contaminated water is a source of foodborne pathogens (Yakov Pachepsky et al., 2011). Flooded water may contaminate the local water and food supply and damage the sewage system, resulting in contamination and increase the potential for communicable diseases (Du et al., 2010). If urban flooding occurs in areas with combined sewer systems, flood water may pose health risks to citizens exposed to pathogens in these waters (Veldhuis et al., 2010). Foodborne diseases are the consequence of consuming contaminated foodstuffs, and range from diseases caused by a multitude of microorganisms to those caused by chemical hazards (WHO, 2014a). Foodborne diseases threaten international public health security. Diarrheal diseases alone - a considerable proportion of which is foodborne - kill 2.2 million people globally every year (WHO, 2014b). Increases in waterborne and foodborne diarrheal disease have been reported in India, Brazil, Bangladesh, Mozambique, and USA, following flooding episodes (Cairncross & Alvarinho, 2006).

              Hue city is located in central Vietnam on the banks of the perfume river. The rainy season is from August to January, with a flood season from October, onwards. Since Hue city has no wastewater treatment plants, fecal pathogens should be always discharged from this city to the Perfume river. Oyster, which is one of the important vehicles for the transfer of foodborne pathogens since it has a potential to accumulate enteric viruses and bacteria, is cultivated in Tam Giang lagoon in the downstream of the river. So oyster is probably affected by contaminants from Hue city, where urban flooding occurs regularly. So far, however, no studies have tried to evaluate the risk of foodborne disease due to urban flood around Hue city. We hypothesize that wastewater from the urban area triggers contamination of oysters, resulted in a considerable health risk. This study is designed to test the hypothesis by evaluating the risk of foodborne disease due to urban flood surrounding Hue city. And develop a methodology to convert risk of foodborne diseases to quality of life based on the feeling of affected people.

Annual flood in Hue

               Methodology: With the aim of evaluating the risk of foodborne infectious diseases due to urban flood surrounding Hue city, we have performed field surveys, lab experiments and using models. We have taken data on contamination of water and oysters at the study site by field surveys. In parallel, we have made interview participants who are randomized to collect related information. After the lab experiments to obtain the key parameters for behaviors of pathogens in water environment, we use models, considering the geographical condition and the predicted occurrence of seasonal floods, to describe their behaviors at the study site. And finally the risk of infection is now being evaluated using the developed model with some supporting data such as the market trade and the consumption of the contamination food. On the other hand, based on the feeling of people in the study site, we are developing a new methodology to convert risk of foodborne disease to quality of life.

Data collection in Tam Giang lagoon (catching oyster)

Data collection in Dam Chuon lagoon (catching oyster)

Researcher was interviewing research's participant

...lab experiments to obtain the key parameters for behaviors of pathogens in water environment.