Distribution of Trihalomethanes in Sea and River Water in Aichi Prefecture

Hajime Ishikawa

Aichi Environmental Research Center, 7-6 Nagare, Tuji-machi, Kita-ku,
Nagoya-shi 462-0032 Japan

Environmental distribution of trihalomethanes (chloroform, bromodichloromethane, dibromochloromethane, bromoform) was studied in closed coastal marine area such as Ise, Kinuura and Atsumi Bays in Aichi Prefecture, and rivers drain into each Bay from August 1996 to May 1998. In surface water samples, chloroform was found in widespread sites, at maximum concentration of 14.46 μg/L in rivers drain into Ise Bay and 1.48 μg/L in Ise Bay, respectively, except for less polluted area in offshore sea and rural inland. In marine area, higher levels of chloroform were found at heavily polluted sites. Bromoform was also determined widely around polluted coastal sites, at maximum concentration of 2.51 μg/L in Ise Bay and 0.14 μg/L in Kinuura Bay, respectively, but rarely in river sites. This indicates bromoform is formed in polluted coastal and estuarine area.
Vertical distribution of trihalomethanes was determined in the interior of bay area. Chloroform levels were high in surface water, but bromoform levels were almost the same from surface to 6 m in depth.

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