POLICY REPORT
ENVIRONMENT

Date: October 20, 1998
File #: VHB02-98
CC File No. 5562
RTS No. 320

TO: Vancouver City Council

FROM: Director of Environmental Health

SUBJECT: Air Quality Impacts of Major Road Network

RECOMMENDATION

A. THAT the G.V.R.D., in cooperation with the Ministry of Environment, Ministry of Health, and Lower Mainland Regional Health Authorities be requested to sponsor a Scientific Panel review of Diesel Exhaust health concerns to provide a better understanding of the risks and trade-offs involved (Partial funding may be available through a recently announced Clean Air Research Fund co-administered by the Canadian Petroleum Products Institute, Ministry of Environment and GVRD);

B. THAT the G.V.R.D. Air Quality Department be requested to initiate near-source monitoring of fine particulates in the vicinity of the Major Road Network, with an emphasis on fine particles of diesel origin;
C. THAT the G.V.R.D. Air Quality Department be urged to expand the number and location of PM2.5 monitoring sites as soon as possible with priority to sites near major road networks;
D. THAT, until such time as the science and technology of the various engine and fuel options and their associated risks and trade-offs are better understood, the GVTA (B.C. Transit) be requested to keep all options open as far as the choice of engine technology and energy source for their fleet;

E. THAT the GVTA (B.C. Transit) be urged to maintain and extend the electric trolley fleet (and other electric-powered mass transit options) on the Major Road Network as an effective means of reducing air quality impacts from transit operations on major arterials and highways;
F. THAT the GVTA (B.C. Transit) be urged to give early consideration to incorporating fuel cell or comparable alternative technology into the Fleet beyond the current commitment to 3 Ballard buses;
G. THAT the Director of Environmental Health and Medical Health Officer, in consultation with the G.V.R.D. Air Quality Department and GVTA (B.C. Transit), report back to Council on completion of the Scientific Panel's review or as further significant developments become known.

GENERAL MANAGER OF COMMUNITY SERVICES' COMMENTS

The Medical Health Officer has indicated that decisions around choice of engine technology, fuel and routing, as these impact on local air quality, need to be based on sound science and will need to involve some trade-offs. While we are told that diesel exhaust is a carcinogen; that natural gas buses provide advantages with respect to local air quality impacts; and that cleaner options such as the Ballard Bus are on the horizon, we need to recognize that diesel technology is unlikely to disappear and currently provides the best option on a benefit/cost basis. We must not lose sight of the fact that an efficient transit system has recognized and significant benefits over the private car with respect to both local air quality impacts and global climate change.

The General Manager of Community Services RECOMMENDS approval of A through G.

COUNCIL POLICY

On July 28, 1998 Council approved the following motion:

"THAT the Vancouver/Richmond Health Board's Environmental Health Department work with B.C. Transit and the G.V.R.D. to clarify (in lay person's language) the issues related to air pollution of vehicles that use major or arterial highways, before Council deals with the major road network report."

Associated policies can be found in Clouds of Change, Transportation Plan and City Plan.

SUMMARY

The issues related to air pollution from vehicles using major or arterial highways are, in one way, related to the regional issues and trends of air pollution and, in another, with the localized air quality impacts mostly associated with particulates and carbon monoxide. While most criteria pollutants are following declining trends, (see Appendix A) these trend lines are flattening with the growth of vehicle use and kilometres travelled in the region. In addition, the measurements on which these trend lines are based do not include actual measurements of fine particles (PM2.5 or less) since the GVRD monitoring network does not utilize this equipment at this time.

With respect to the specific concern about diesel exhaust the following issues are highlighted:

· The California Air Resources Board (CARB) has declared diesel exhaust as a toxic air contaminant, largely based on the toxic properties of diesel particulate.

· The 1998 draft US EPA document concluded that diesel exhaust be considered a "probable" human carcinogen.
· Having identified diesel exhaust as a health risk, CARB has not proposed to ban the use of diesel fuel, as this would be impractical. CARB intends to commission further research to review the cost and effectiveness of mitigative measures such as further reformulation of diesel fuel.
· The detrimental effects of fine particulates (PM 2.5 - particles less than 2.5 microns in size which get deep into the lungs) such as emitted in diesel exhaust are attracting greater attention by health effects researchers and health professionals.
· There is no common agreement as to the size of particles that should be monitored (although the U.S. EPA has adopted a PM2.5 standard others argue for a limit of PM1 (1 micron or less in size)) nor how that monitoring should be conducted.
· The new "clean technology diesel" engines emit substantially less particulate matter (about 90% by weight) than pre-1990 models. Researchers are now looking into particles with smaller diameter that have substantially larger surface area compared to larger particles, and may pose an increased health hazard. However, research in this area is in its infancy.
· A few studies exist which explore in greater depth the "on-road" emission characteristics of diesel engines versus alternate fuel (Natural Gas) engines in transit use, and which appear to indicate that natural gas provides some significant air quality advantages offset by some financial and fuel efficiency deficits. More work is required in this area specific to the BC Transit fleet.

PURPOSE

This report is written in response to Council's request for a clarification of the issues related to air pollution from vehicles using major arterials.

DISCUSSION

As a result of discussions between B.C. Transit, the GVRD Air Quality Department and the Environmental Health Division of the Vancouver/Richmond Health Board, the following analysis is provided as requested by Council. An effort has been made to clarify the current state of knowledge about air pollution from arterial traffic in lay person's terms although scientific terminology has been retained where absolutely necessary.

BACKGROUND

The GVRD is responsible for the Air Quality Management Plan (AQMP) which was adopted in December 1994 and contains 54 emission reduction measures and 33 recommendations designed to address priority air quality issues in the region and achieve an overall emission reduction of 38% between the years 1985 and 2000. The GVRD monitors air quality and has also conducted a series of modelling exercises to estimate the contributions of various sources to the region's air pollution, the latest of which is contained in the 1997 Emission Inventory.

Mobile sources are responsible for the major portion of emissions of common air contaminants in the region (Figure 1).

It also must be borne in mind that not all pollutants are of equal concern, nor is tonnage of emissions an accurate measure of relative health impacts.

The five common air contaminants on which the GVRD AQMP reduction target is based are:

· carbon monoxide (CO)
· volatile organic compounds (VOCs)
· nitrogen oxides (NO_x)
· sulphur oxides (SO_x)
· particulate matter (PM)

Figure 1 - 1997 LFV Emissions of the Five Common Air Contaminants (GVRD)

The AQMP identifies a number of priority regional air quality issues. The greatest health concern surrounds small particles, a subset of total particulate matter:

· inhalable particulate matter i.e. particles smaller than 10 microns in diameter (PM10)

· fine particulate matter - the fraction smaller than 2.5 microns (PM2.5)

Particles come from a variety of sources, and can react in the air with other chemicals that occur naturally and other pollutants. The particles that are the cause of most concern are the products of combustion (for example, "soot"). The particles that are formed in the atmosphere as a result of the interaction of other pollutants ("secondary particles") are also a serious health concern.

In addition vehicles contribute significantly to greenhouse gas emissions

· carbon dioxide (CO₂)
· methane (CH₄)
· nitrous oxide (N₂O)

CURRENT ISSUES

While air quality in the region is generally good, trends in traffic growth are disturbing. The number of vehicle kilometres travelled is increasing, the average occupancy of those vehicles is falling and the share of travel by transit in peak periods has not increased significantly. All these trends are contrary to the strategy for region (which all levels of government have adopted) which seeks to reduce dependence of the private vehicle for travel as a major component of the effort to maintain and improve the air quality of the region.

Action has been taken to reduce the amount of pollution from vehicles. More stringent vehicle emissions standards, adopted by Canada in 1988, have significantly reduced the pollution from all vehicles. Cleaner fuel specifications, including the mandatory use of low sulphur diesel on roads in B.C. have also made a significant contribution to cleaner air. New regulations requiring roadside tests of heavy duty vehicles emitting visible smoke are being introduced into the Lower Mainland this year.

There has been growing concern that the standards that are used to monitor air quality and to specify the emissions performance, particularly of heavy duty vehicles are not adequate to reduce the most serious health risks. In July 1997 the United States Environmental Protection Agency (EPA) introduced new standards for fine particulates.

Before 1987, EPA's standards regulated larger particles (so called "total suspended particulates"), including those larger than 10 micrometers. By 1987, research had shown that the particles of greatest health concern were those equal to or less than 10 micrometers that can penetrate into sensitive regions of the respiratory tract. At that time EPA and states took action to monitor and regulate particulate matter 10 micrometers and smaller.

In the years since the previous standard was enacted, hundreds of significant new scientific studies have been published on the health effects of particulate matter. Recent health effects studies suggest those adverse public health effects, such as premature deaths and increased morbidity in children and other sensitive populations, have been associated with exposure to particle levels well below those allowed by the current standard.1

The new US National Ambient Air Quality standard is expressed in terms of particulate matter 2.5 micrometers and smaller (PM2.5). So far Canada has not followed the U.S. lead, although there is considerable pressure to do so. Consultations are currently underway to set Canada-wide standards for particulate matter (PM10 and PM2.5) and ozone. Monitoring equipment to measure PM2.5 is only installed at one station in the region, with plans for more installations by next summer. Standards for emissions from vehicles continue to be expressed as total particulate matter.

The California Air Resources Board (CARB) on August 27 1998 identified diesel exhaust as a Toxic Air Contaminant i.e. "An air pollutant which may cause or contribute to an increase in mortality or an increase in serious illness, or which may pose a present or potential hazard to human health"2 This requires that CARB prepare a report which assesses the need for and appropriate degree of control of diesel exhaust. The analysis will determine what if any further regulatory action to reduce exposure to diesel exhaust is necessary. "Staff will not be considering a ban on the use of diesel fuel or diesel engines, because such a strategy would not be technically and economically feasible"3 CARB notes that since 1988 particulate matter emissions from new heavy duty diesel truck engines have been reduced by over 85% and from urban bus engines by over 90%. Measures are being developed to reduce emissions from diesel engines through fuel specifications for railway locomotives, more stringent standards for light and medium duty vehicles and more stringent standards for off road diesel equipment. Ambient levels of diesel exhaust PM10 in California are expected to be reduced by about 20% from 1995 to 2010. "If a need for further control is found the CARB staff would examine strategies such as tighter emissions standards for new vehicles; further reformulation of diesel fuel; maintaining low emissions in use; and incentive programs to promote accelerated turnover of in use diesel engines and alternative engine and fuel technologies."4

The 1998 draft US EPA document5 concluded that diesel exhaust be considered a "probable" human carcinogen. Based on available scientific evidence, a level of diesel exhaust exposure below which no carcinogenic effects are anticipated has not been identified.

Air Quality monitoring data reflects the need to assess the region as a whole: there are 24 continuous air quality monitoring across the region, 16 "non- continuous" monitors and a mobile air monitoring unit (MAMU). None of these stations specifically examines the impact of emissions from road vehicles - however monitored species such as carbon monoxide do reflect emissions from the mobile sector While the levels of inhalable particulate tend to be generally well below the acceptable objective, exceedances recorded tend to be associated with particles at the higher end of the size range - road dust, sand and soil. Higher level, near-source exposures to diesel exhaust occur near busyroads and intersections where many diesel vehicles are operating. CARB report diesel exhaust concentrations as much as five times outdoor ambient conditions near major arterials (freeways). There is a need to explore these near-source exposures further.

Emission Reduction Measures to Reduce Fine Particulate

No specific measures have been identified for controlling emissions of fine particulate matter. However, measures in the AQMP that focus on controlling total particulate emissions from various sources will also reduce fine particulate. Enhanced vehicle emission standards, new fuel standards, increased fuel combustion efficiency in boilers and heaters, transportation demand management measures, improved land use and transit planning - will all help control fine particulate emissions.

Emission reduction measures that control emissions of sulphur and nitrogen oxides will also reduce the formation of various sulphates and nitrates in the atmosphere that lead to fine particulate matter." 6

The B.C. Cleaner Gasoline Regulation requires that by January 1, 1999, gasoline sold in the Lower Fraser Valley and Vancouver Island must have a maximum average sulphur content of 150 ppm or equivalent. The BC Motor Vehicle Emissions Reduction Regulation requires that by model year 2001, vehicles offered for sale must be certified to California "low emission vehicle" standards. In addition, recently announced Federal gasoline regulations are expected to cap the average sulphur content of all Canadian gasoline at the "California" standard of 30 ppm in 2005.

Ambient Measures
Recognizing the threat that PM10 poses to human health, the [BC] Ministry [of Environment Lands and Parks] followed the lead of the GVRD in establishing an air quality objective for PM10 before the national body recommended levels for a national PM10 objective. This interim objective is intended to provide guidance for environmental protection decisions while the national air quality objective for PM10 (and PM2.5) is being prepared. The British Columbia PM10 objective will be evaluated in the context of the national objective once the latter has been finalized.

The interim level for PM10 is intended to be equivalent to a maximum acceptable level in the national air quality objective system.

"Air Quality Objective:
PM10 24 Hour Average Concentration at 25^o C and 101.3 kPa 50 mg/m3"7

The GVRD Objectives are the same for 24 hour and 30 mg/m³ for one year. In 1996 mean PM10 readings in the region were between 15 - 20 mg/m³ at most sites. Monitoring of total suspended particulates showed that only thirteen of 1614 samples exceeded the 24 hour objective. These exceedances were due to isolated local sources close to the sampling sites and were not indicative of more widespread particulate levels in the region. 8

The "Clean Diesel" Controversy and Natural Gas

As a result of the more stringent vehicle emissions standards, manufacturers of diesel engines for road vehicles have adopted four-stroke, electronically controlled engines to replace the two stroke engines that were common in trucks and buses in North America. One research study showed that a new technology engine, with the emission control equipment removed, produced a larger number of fine particles than an older engine.9 Engine tests for particles required by law measure the mass (weight) of particles. The technique used in this experiment counted particles in each class size. The particles that are produced by fuel combustion in diesel engines (primary particles) do not persist in their original state for very long, because they react to the chemicals in the air. For this reason, the current EPA regulations require diesel emissions to be sampled from exhaust gas diluted with air. "Although results from different laboratories confirm the increased number [of small particle] emissions from newer engines, there is a considerable spread of the reported particulate number concentrations. An important reason for the spread of experimental results is the influence of exhaust gas sampling and dilution parameters on the properties and size distributions of diesel particulates. The exhaust gas dilution which takes place in a laboratory is not a good simulation of atmospheric processes" 10
A recent study ¹¹ conducted on in-use diesel and natural gas buses using Central Business District cycles found that " CNG powered buses yielded PM emissions more than an order of magnitude lower than their diesel counterparts (e.g. .025 g/mile vs. .66 g/mile) and NOx emissions were a third lower than the diesel bus levels. The CNG busesemitted about twice the level of CO as the diesel buses." It would be of interest to commission similar "in use" emission testing for the existing natural gas, existing diesel and new diesel buses in the BC Transit fleet to evaluate the effectiveness of emissions control systems.

Some of the trade-offs with respect to natural gas buses include lower fuel efficiency (~20%) as compared to diesel, higher acquisition costs (~$70,000) potentially offset by lower fuelling costs, and the requirement of a gas compressor to be installed at the Operating Centre at a cost of around $1m for 100 buses. So far, trials of natural gas buses in Port Coquitlam have shown that they are less reliable and require more spares coverage than diesel buses, although this is expected to improve as the new technology is better understood by manufacturer and operator alike.

The Major Road Network and Pollution

Both B.C. Transit and the City of Vancouver have been part of the process by which the proposed MRN has been determined by the transition team for the GVTA. The bus route network in the City of Vancouver is a much finer grid than the MRN and many of those routes are operated by pollution free electric trolleybuses. While on road mobile sources are responsible for much of the pollution, light duty vehicles are the cause of most of the concern.

While there are 20,000 heavy duty vehicles registered in this area (all of which would have diesel engines) there are 774 diesel buses. The only way to estimate the contribution of the MRN to air pollution would be to commission further runs of the GVRD's traffic and air pollution models. This could determine the number of vehicle kilometres travelled on the MRN and the rest of the modelled network (which would exclude most residential streets) by vehicle type, and then calculate the emissions produced per vehicle kilometre travelled for the fleet average. It may be possible to extract this information from contract studies completed by Levelton Engineering for the production of the 1997 Inventory. It should be noted that the model used to estimate particulate emissions is based on the US fleet as the PART5 model has not been modified for use in Canada. Results are heavily dependent on assumptions about the fleet composition in terms of vehicle size and age.

Pollutant (% of LFV Total)	Light duty vehicles	Heavy duty vehicles
Carbon Monoxide	81.5%	2.5%
Volatile Organic Compounds	26.8%	1.1%
NOx	35.9%	11.6%
SOx	10.8%	2.3%
Total particulate	1.8%	1.8%
PM10	3.3%	3.2%
PM2.5	3.4%	4.9%
Greenhouse gases	27.6%	4.5%

Source: Lower Fraser Valley 1997 Emission Inventory GVRD
Note: It should be noted that road dust and secondary particulate formation have been excluded from this inventory.

Given that emissions are proportionate to vehicle kilometres travelled, it is not clear that such a study would add significantly to our knowledge. While heavy duty vehicle trips tend to be confined to the MRN by local traffic regulations on maximum permitted vehicle weight, trips on local roads to make deliveries and provide essential services will always need to continue.

It is clear that, given the very much higher vehicle occupancies of buses compared to cars, improving the share of the market served by transit as opposed to single occupant vehicles, can significantly impact emissions. In order to achieve this, buses must be made more attractive, particularly by making them less subject to the effects of traffic congestion.

Emissions in grams per vehicle kilometre	Older diesel bus	"Clean"diesel bus	Car
HC	0.76	0.14	0.14
CO	2.29	1.57	13.30
NOx	6.59	6.72	1.30
PM	0.30	0.06	0.03

Sources: BC Transit calculations

Health Impacts and Research Needs:

The Environmental Health Director and Medical Health Officer have consulted with the Ministry of Health Medical Toxicologist, Dr. Ray Copes, on the specific issue of diesel exhaust particulate. Adoption of a Canada-wide Standard for PM10 and PM2.5 is expected within the next year. In the meantime, the following suggested strategy is provided for Council's consideration:

· A better understanding of the actual nature and toxicity of the ultra-fine diesel particles is needed. The commissioning (by the GVTA, GVRD, Ministry of Environment, & Ministry of Health) of a Scientific Review Panel on the issue of health risks from diesel exhaust is recommended. A source of funding may be available through a recently established Clean Air Research fund co-administered by the Canadian Petroleum Products Institute (CPPI), B.C. Ministry of Environment and the GVRD.

· Actual fine and ultra-fine particle levels in near-source conditions (i.e. along major roads) need to be measured to permit a more accurate risk assessment. The GVRD's Mobile Air Monitoring Unit (MAMU) could be utilized along parts of the proposed Major Road Network to determine near-source air pollution impacts, especially those related to fine particles from diesel combustion.

· The GVRD's Monitoring network needs to be upgraded to PM2.5 monitoring equipment as soon as possible (e.g. in advance of a Canadian PM2.5 standard being adopted).

· The GVTA (BC Transit) should explore the costs and benefits of commissioning an "in-use" analysis of transit bus emissions from alternative engine/fuel choices rather than relying on chassis certification test data to extrapolate on road conditions.

CONCLUSION

There is inadequate information available at this time to provide a definitive response to Council's inquiry about air pollution impacts from the Major Road Network, especially as this relates to diesel exhaust. The only answer is that there is no easy answer. The various air pollutants can not be evaluated and controlled in isolation from each other. Nor, can public policy decisions be made solely on the single criterion of air quality - trade-offs will need to be made. A program of further research is required coupled with keeping the region's options open with respect to the engine and fuel choice for the transit fleet.

*****

Appendix A (from GVRD Ambient Air Trends Document)

(c) 1998 City of Vancouver

1 http://ttnwww.rtpnc.epa.gov/naaqsfin/pmhealth.htm (July 17, 1997)
"Health and Environmental Effects of Particulate Matter" US EPA

2 Section 39655 California Health and Safety Code

3 Initial Statement of Reasons for Rulemaking: Proposed Identification of Diesel Exhaust as a Toxic Air Contaminant CARB June 1998

4 Ibid

5 Health Assessment Document for Diesel Emissions, Review Draft US EPA, February 1998

6 Let's Clear the Air: Priority One Air Quality Issues GVRD

7 Final Air Quality Objectives for Formaldehyde and the Interim Air Quality Objective for Fine Particulate: PM10 Air Resources Branch, Environmental Protection Department, Ministry of Environment, Lands and Parks January, 1995

8 Ambient Air Quality Annual Report GVRD 1996

9 "Effects of Fuel Modification and Emission Control Devices on Heavy Duty Diesel Engine Emissions" Susan T Bagley et al Health Effects Institute, Research Report Number 76, 1996

10 "The Nature of Diesel Nanoparticles May Require Rethinking of Particulate Matter Standards" W. Addy Majewski in Diesel Progress June 1988

11 "Natural Gas and Diesel Transit Bus Emissions: Review and Recent Data" Nigel N. Clark et al in
Society of Automotive Engineers, SAE Paper No. 973203, 1997