October 2014, Durban
---Background paper by the Japan Medical Association---
Japan’s experience with the prevention of air pollution and emissions from
vehicle exhaust: Focusing on the reduction of exhaust emissions from
diesel-powered vehicles
When examining the recommendations in this draft WMA declaration, it is apparent that nearly all of
the items listed have already been implemented in Japan through public-private cooperation.
1. (Gradual reduction plans and plan realization)
In Japan, to reduce motor vehicle exhaust emissions, a series of emissions limit values for newly
manufactured and marketed vehicles were established, known as "Long Term Standards" (1997);
"New Short Term Standards" (2003); "New Long Term Standards" (2005), and "Post New Long
Term Standards" (2009).
Through these standards, it was planned that motor vehicle emissions
would be cleaned up by implementing measures so that motor vehicles that did not achieve these
limit values would not be able to be marketed. The most recent "Post New Long Term Standards"
were implemented for two years in 2009 and 2010, and all new vehicles achieved the emissions limit
values set out in them. All relevant parties are currently making considerable efforts towards further
improvements to achieve the "Advanced Exhaust Emissions Standards" that will be implemented by
the national government and industry beginning in 2016.
2. (Reduction plans established by the national government)
On March 25, 2008, the Ministry of Land, Infrastructure, Transport and Tourism published the
document titled "Stronger Motor Vehicle Emission Standards (Post New Long Term Standards):
Gradual Strengthening for New Diesel-powered Motor Vehicles from 2009" on its website. In the
first paragraph, it stated the following: "In order to further reduce nitrous oxides (NOx) and
particulate matter (PM) emitted by new trucks, buses and passenger vehicles, the Ministry of Land,
Infrastructure, Transport and Tourism recently (on March 25) established the highest level of
standards in the world, the 'Post New Long Term Standards.'
These will gradually become mandatory for new diesel-powered vehicles in stages beginning in
October 2009. From this date it will also be possible to conduct inspections based on these new
standards [...]."
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In addition, it explains that for "diesel-powered vehicles [...] limit values for exhaust emissions for
new trucks, buses and passenger vehicles will be reduced substantially--NOx by 40-65% and PM by
53-64%--and exhaust emission standards will be basically reduced to the same level as that for
gasoline-powered vehicles."
As reference material, an overview table shows emissions standards by type of vehicle, measurement
method and units of measurement, and the date that standards began to be applicable, but this table
has too much information. Instead, Reference Material No. 2, "Development of Vehicle Emission
Standards (Heavy Duty Diesel-powered Vehicles)" is presented here below in its entirety. The table
shows the rate of reduction in the amount of nitrous oxides (NOx) and particulate matter (PM) in
exhaust emissions from heavy duty diesel-powered vehicles from 1974 to 2009, with the amount in
1974 set at 100. By 2009, NOx was reduced to 5% of 1974 levels, and PM was reduced to 1%.
[Figure 1]
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(International Comparison in 2013)
The information from the government of Japan is somewhat older, but in 2013, the Japan
Automobile Manufacturer Association (JAMA) released its "Environmental Report 2013: Measures
Taken to Reduce the Environmental Impact of Motor Vehicles". In the section titled "Improved Air
Quality" it presents the following chart that compares gasoline-powered vehicles and diesel-powered
vehicles in the US, EU and Japan. The following is an unofficial translation of an excerpt from this
section.
(1) Changes in standards for exhaust emissions in gasoline-powered vehicles
For gasoline-powered vehicles, the first standards were introduced in 1966 for carbon monoxide
(CO), and in 1973, limit values were added for hydrocarbons (HC) and nitrous oxides (NOx) with
implementation of the "1973 Exhaust Emission Standards." Subsequently, standards which reduced
the limit values for these three substances were introduced gradually.
In the "2005 Exhaust Emission Standards (New Long Term Standards)" introduced in 2005 and the
even more strict "2009 Exhaust Emission Standards (Post New Long Term Standards)" added new
standards for PM emissions from one kind of gasoline-power vehicles (those with direct-injection
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engines equipped with NOx-adsorber catalyst systems), the same level as for diesel-powered motor
vehicles (0.005 g/km).
(2) Measure to Reduce Exhaust Emissions in Gasoline-powered Motor Vehicles
Each member company of JAMA has made positive steps to introduce certified low emission
vehicles. Certified low emission vehicles exceeded 98% of all new vehicles sold in 2012, a total of
4.02 million units. Of these, over 96% have met the 4-star 2005 standards.
Each member company of JAMA has experimented with various methods and taken measures when
new exhaust emission standards were
introduced. In gasoline-powered vehicles today, the main method to reduce exhaust emissions uses
electronically-controlled fuel injection systems and catalysts. Precision control of combustion
through advanced fuel control technology and catalytic technology have developed as the main
technology.
The low emission certification system established values with additional 25%, 50% and 75%
reductions from the exhaust emission limit values in the "2000 Exhaust Emission Standards."
The "2005 Exhaust Emission Standards (New Long Term Standards)" introduced in 2005 set
certification standards as 50% and 75% of limit values. This significant reduction compared to the
limit values promoted the widespread adoption of certified low-emission vehicles, which reduced
exhaust emissions considerably.
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[Figure 2 here, gasoline US/J/EU Comparison]
(3) Developments in Exhaust Emission Standards for Diesel-powered Motor Vehicles
For widely-used diesel-powered vehicles, primarily commercial trucks and buses, black smoke
emissions were regulated in 1972; limit values for CO, HC and NOx were added in 1974 with the
implementation of the "1974 Exhaust Emission Standards."
The "2009 Exhaust Emission Standards (Post New Long Term Standards)" introduced in 2009
tightened the limit values for NOx (0.7g/kWh) and PM (0.01g/kWh) to levels much stricter than
those of the US or Europe.
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[Figure 3 here, diesel, US/J/EU Comparison]
This is clear in the two figures shown here. The level of emission standards achieved in Japan on a
per-car basis are the best levels in the world.
4. Vehicle Type Standards
In this way, Japan has developed an extremely strict standards regime for vehicle exhaust
emissions. But Japan is also planning in addition to introduce a "Act on Motor Vehicle NOx PM" (Act on Special Measures for Reduction of Total Volume of Nitrous Oxide in Motor
Vehicle Exhaust Emissions in Designated Regions). This will establish designated districts (the
Metropolitan District including Tokyo, Kanagawa, Chiba and Saitama; the Aichi-Mie District
around Nagoya, and the Osaka-Hyogo District including Osaka and Kobe) in which various
methods will be introduced as measures to prevent roadside pollution, such as limiting the kinds
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of motor vehicles able to enter these districts by the main roads, especially diesel-powered
commercial vehicles, according to so-called vehicle type standards based on year of production.
The effect of these standards will clearly be a trend to reduce sharply the volume of nitrous
oxides (NOx) and fine particulate matter. It must also be pointed out that the newest advanced
scientific knowledge will be required, e.g. for the development of instruments capable of
continuous measurement of the conditions in pollution control districts, and that the country
must bear an additional economic burden in order carry out these measures.
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