Policy evaluation of vehicle exhaust standards in Japan from 1995 to 2005 based on two human health risk indices for air pollution and global warming

Measures for vehicle exhaust emissions aimed at reducing either air pollution or global warming could have counterproductive effects on one another. Increasing diesel passenger vehicles, which generally have lower CO2 emissions than gasoline counterparts, leads to increasing particulate matter (PM) emissions, while gasoline has lower PM emissions than diesel. It is said that stringent limits on PM emission factors discourages improved CO2 emission factors. Without including both effects in a risk evaluation, one cannot evaluate whether the total risk is reduced or not. Hence, we evaluated representative exhaust emission measures based on risk evaluation for both air pollution and global warming. Considering consumer choice between diesel and gasoline passenger vehicles and emissions standards adopted in Japan from 1995 to 2005, we built five cases for vehicle policy evaluation. For each case, we estimated disability-adjusted life years (DALY) as an index of human health risk caused by lung cancer linked to inhalation exposure of elemental carbon in PM as well as due to global warming linked to CO2. The results of our risk evaluation reveal that the case adopting the 2005 new long-term Japanese emission standard reduces the human health risk caused by lung cancer due to air pollution by 0.6 × 103 DALY, but would increase the risk due to global warming by 31.9 × 103 DALY compared with the case of adopting EURO 4, for the same conditions of passenger vehicle choice from 1995. These results suggest that the characteristics of Japanese emissions standards are mainly designed to reduce air pollution.

[1]  A. Inaba Life-cycle Impact assessment Method based on Endpoint modeling , 2012 .

[2]  D. Gaylor Preliminary estimates of the virtually safe dose for tumors obtained from the maximum tolerated dose. , 1989, Regulatory toxicology and pharmacology : RTP.

[3]  J. Murray,et al.  The Global Burden of Disease , 1996 .

[4]  Zachary A. Collier,et al.  Risk-based standards: integrating top–down and bottom–up approaches , 2014, Environment Systems and Decisions.

[5]  M. Lipsett,et al.  For the " Proposed Identification of Diesel Exhaust as a Toxic Air , 2022 .

[6]  S. Tohno,et al.  Estimation of Elemental Carbon Emission and Spatial Distribution of Atmospheric Concentration in Kansai Area , 2008 .

[7]  M. Huijbregts,et al.  Characterization factors for global warming in life cycle assessment based on damages to humans and ecosystems. , 2009, Environmental science & technology.

[8]  Tammy O. Tengs,et al.  Five-hundred life-saving interventions and their cost-effectiveness. , 1995, Risk analysis : an official publication of the Society for Risk Analysis.

[9]  E. Helmers,et al.  Critical evaluation of the European diesel car boom - global comparison, environmental effects and various national strategies , 2013, Environmental Sciences Europe.

[10]  Kazuya Inoue,et al.  Development of an Atmospheric Dispersion Model for Exposure and Risk Assessment (ADMER) , 2003 .

[11]  W. Cullen,et al.  Research confuses me: what is the difference between case-control and cohort studies in quantitative research? , 2013, Irish medical journal.