Tsunami and Environmental Pollution Hazards: A Note for the Restoration Process - Post-Tsunami Hazard: Reconstruction and Restoration - page 269

collected from Marumori-cho in Miyagi has shown to be high in radioactive cesium
( 137 Cs and 134 Cs) in amounts larger than 6,000 Bq/kg (ACRO 2013 ).
Considering the problem of radiation and its accumulation, local authorities and
citizens have expressed deep concern about incinerating debris from Miyagi
Prefecture. Reports by the government claim that radiation levels are very low, for
example, in the city of Ishinomaki where the largest amount of debris exists,
radioactive readings were 0.055 ( Svh −1 ), appearing to be similar to its surroundings

(Recovering Tohoku 2012 ). Nonetheless, the city of Kitakyushu has accepted to
burn 23,000 t of debris amid strong opposition by its citizens (Japan Today 2012 ).
The Environment Ministry has set further safety guidelines for ash originating
from debris incineration in contaminated areas, stating that up to 8,000 Bq/kg of
radioactive cesium can be buried safely like any other type of waste (The Asahi
Shimbun 2012 ).
Radioactive materials from the Fukushima nuclear plant has contaminated soil
and waterways in Miyagi, likely creating some radioactive “hotspots”. For example,
studies have shown the Murone and Yagoshi mountains along the Okawa river
watershed ending at Kesennuma have a certain amount of radiation, raising concerns
about dispersion of radioactive elements and their potential impact (Tanaka M,
International Institute for Advance Studies, Kyoto University, Japan, 2012, personal
communication). Although fi gures vary according to sources at the time of sampling,
it is clear that radioactive contamination appeared to have occurred in Miyagi
Prefecture as result of the Fukushima Dai-ichi nuclear plant disaster.

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17.5 Environmental Contamination and Toxicity

Toxic effects of pollutants could result in death or ailments in the short, medium and
long-term. Moreover, depending on the type of exposure and the level of response,
they could be considered acute or chronic (Environmental Health and Safety 2013 ;
University of Toronto 2013 ). The degree of toxicity depends on the particular type,
concentration, activity-reactivity, physicochemical characteristics, persistence of the
compounds as well as the target (species) and exposure time. Moreover, combined
mixtures of pollutants could result in stronger (potentiated and synergistic) or weaker
(antagonistic), toxic effects (VKM 2008 ).
Toxic effects may produce growth abnormalities and teratogenesis, cell and tissue
damage, chromosome mutations or changes in behavior as well as alterations in
reproductive rates, among many other problems (US-EPA 2011 ). A large number of
studies have been carried out on the effects of toxic substances on species and
compiled in metadata such as the ECOTOX Database focusing on aquatic, terrestrial
plants and wildlife (USA-EPA 2014 ).
Considering the type of chemicals spread by the tsunami in Miyagi Prefecture
from industries, processing factories, warehouses, households, garages, hospitals, etc.
as well as those potentially released from wooden debris, the likelihood of environ-
mental and human health risk hazards could be high. This would be particularly