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The Dynamic Performances of DDTs in the Environment and Japanese Exposure to Them: A Historical Perspective after the Ban
Author(s) -
Morisawa Shinsuke,
Kato Atsushi,
Yoneda Minoru,
Shimada Yoko
Publication year - 2002
Publication title -
risk analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.972
H-Index - 130
eISSN - 1539-6924
pISSN - 0272-4332
DOI - 10.1111/0272-4332.00019
Subject(s) - perspective (graphical) , environmental science , engineering , aeronautics , computer science , artificial intelligence
The fugacity model for evaluating DDTs dynamic performances in the environment was combined with the dietary exposure evaluation model, including the contribution of imported food, to develop the macroscopic mathematical model relating DDTs in the environment with the health risks of the reference Japanese. The model validity was examined by comparing the simulated DDTs concentrations in environmental media, various kinds of food, and dietary intake with those observed. Numerical simulations were done for the past half and future of one century to evaluate the effect of the DDTs usage prohibition in 1970 in Japan. The major results obtained under the limits considered are as follows. The DDTs concentrations in environmental media, various kinds of foods, and the dietary intake showed the steady exponential decrease after the DDTs usage prohibition in 1970. The DDE/DDTs ratio is larger in the higher position in an ecological system, and increased steadily with time. The critical exposure of DDTs occurred through animal product intake until 1960; after 1990 marine product intake caused the most exposure. The estimated DDTs intake was evaluated to be less than the PTDI and R f D. The annual excess cancer induction risk due to the annual dietary intake of DDTs was the largest at the level of (0.5−2.0)×10 −6 (1/yr) in the early 1970s. The effect of the DDT usage prohibition on dietary exposure reduction was expected to appear after about 20 years. The life‐span excess cancer induction risk was conservatively estimated to be larger than 10 −5 (1/lifespan) for the reference Japanese who were born before 1970. The DDTs usage prohibition in 1970 was effective to reduce the life‐span cancer risk under the 10 −5 level.