Tsunami and Environmental Pollution Hazards: A Note for the Restoration Process - Post-Tsunami Hazard: Reconstruction and Restoration - page 264

insecticide containing silica, has been in use since 1981 for treating timber due to its
low toxicity to mammals and fi sh as well as its high stability under sunlight, soil and
alkaline environments (Katsuda et al. 2011 ).

17.3 Debris Management in the Aftermath

Tsunami debris had an enormous impact in the affected areas along the coastline,
creating large problems (Santiago-Fandiño 2013b ). The costs involved in managing
debris have been staggering; in Ishinomaki City alone, they are estimated to reach
US$ 262.5 million or about 21.2 million Yen (Tisnadibrata 2013 ). The total amount
of debris generated in the Ishinomaki block equaled about 68 years of general waste
while in Watari-Natori block about 50 years (MPG 2014 ).
Governments need to estimate the amount of debris and also prioritize their
cleanup as soon as possible as debris blocks roads, obstructing humanitarian relief
and rescue efforts. Furthermore, as debris may also carry toxic and or hazardous
chemicals, they present a variety of potential environmental and health hazards.
Studies towards the establishment of disaster debris management based on quantita-
tive estimation using natural hazards maps could be used in emergency response
and pre-disaster planning (Hirayama et al. 2010 ).
If clean-up and disposal is not properly carried out, secondary impacts on the
environment are likely to occur (Srinivas 2005 ). For example, burning construction
debris in the open could produce PAH's and other toxic compounds (Bird and
Grossman 2011 ; Japan Society for Material Cycles 2011 ). In the city of Minamisanriku
(Miyagi Prefecture), debris containing plastics, vinyl, seawater-soaked wood, wiring
and insulation materials appears to have been burned during the initial cleanup
process as seen in Fig. 17.5d (Bird and Grossman 2011 ).
Mixed debris once stored in temporary sites are moved to new ones for further
sorting and segregation, treatment, incineration, recycling and/or disposal. During
this waiting period, debris tends to adhere to soil and/or sand, making further
processing and incineration more diffi cult (MPG 2013a ).
Construction materials and storage sites containing organics or gypsum, particu-
larly in wet environments, generate methane and hydrogen sulfi de gases. This is due
to bacterial degradation of organic compounds. High concentrations of these gases
present a serious health and fi re hazard if not properly managed (Ohio-EPA 2011 ;
ATSDR 2013 ). Sudden explosions have already occurred in temporary storage sites
in Miyagi (UNEP 2012 ).
Traditional tatami mats are manufactured using a variety of vegetation products
such as straw as well as other materials like clay-based dyes (Fujimoto and Muller
2004 ). Tatami mats are capable of maintaining high levels of moisture facilitating
decomposition and generation of fl ammable gases, necessitating proper storage con-
ditions to avoid further hazards or accidents (Fig. 17.6 ).
In terms of greenhouse (GHG) emissions and CO 2 “footprint”, Cui et al. ( 2013 )
made a preliminary assessment calculating that 10.95 Mt CO 2 -eq. was due to debris.