貸おむつのGHG排出量の算定

抄録

Objective. Japan is increasingly becoming a society with fewer children, higher proportions of elderly citizens, and growing numbers of working women and nuclear families. These changes have driven a shift from cloth diapers to disposable diapers. By 2010, 95% of infants and 85% of adults who used diapers used disposable rather than cloth diapers. Nevertheless, due to factors associated with comfort, environmental issues, and benefits during diaper training, entrenched demand for cloth diapers remains. Use of cloth diapers is generally more time-intensive. Cloth diaper rental services offer consumers who choose to use cloth diapers the promise of greater convenience. Our study used data collected from three diaper rental plants covering the period from February 2010 through April 2012. We performed LCI analysis for individual processes in two different washing systems to assess the GHG emissions generated by cloth diaper rental services.
Results and Discussion. For the cloth diaper rental industry, the results showed that regardless of differences between washing systems, the gas used to fuel the central steam boilers at the plants accounted for the largest proportion of overall GHG emissions, followed by electricity. For a system involving 12 continuous washing machines, the gas used to heat the washing water accounted for the greatest proportion of GHG emissions. For fully-automatic batch washing systems, the gas used for drying accounted for the greatest proportion of GHG emissions. Processes associated with dry cleaning shirts on the one hand and laundering rental cloth diapers on the other generated comparable levels of GHG emissions.
Conclusions. The results of our study suggest that improved boiler efficiency may be a key factor in reducing GHG emissions. Comparisons of GHG emissions for disposable diapers and cloth diaper rentals showed no clear advantages or disadvantages for one or the other.