As indicated in the April 2019 blog 1, when fossil fuels are combusted nitrogen oxides (NOx), including nitrogen dioxide (NO2), are formed. Combustion processes are currently used in transportation, heating, power generation, and oil and gas development. NOx contributes to the formation of ozone and at high concentrations can be seen over large cities as a brownish haze. Two examples of health effects of elevated NO2 concentrations in the air are irritation to the respiratory system and possible lower resistance to respiratory infections. New CAASS for NO2 will come into effect in 2020.

In Canada overall NOx emissions have been trending down due to improvements in vehicle emissions standards and technological advances in engines, and public transit improvements in major centres. However, Alberta remains the number one contributor of ambient air NOx in Canada. Development of oil and gas resources has been suggested to be the driver of these high overall NOx. concentrations.


The April 2019 blog presented NO2 ambient air monitoring results in Calgary’s Regional Airshed Zone (CRAZ) that meet or just exceed the future CAAQS if the NOx emissions remain constant. The greatest contributor of NOx. in the CRAZ is transportation (61%) and upstream oil and gas (19.5%) as indicated in the table below, based on 2008 data 2,

Table 5 2008 CRAZ Emissions by Sector – Percentage

Main Sector Unit:% CRAZALL
AGR CRAZALL 0.1% 0.1% 15.5% 89.0% 0.4% 3.4% 10.1%
COMM CRAZALL 3.0% 7.0% 1.4% 0.2% 4.6% 6.8% 1.5%
EGU CRAZALL 0.2% 3.2% 0.0% 1.9% 0.7% 0.3% 0.1%
UOG CRAZALL 3.7% 19.5% 8.9% 0.9% 74.7% 0.8% 0.2%
SOL CRAZALL 0.0% 0.0% 9.0% 0.0% 0.0% 0.0% 0.0%
GAS CRAZALL 0.0% 0.0% 5.3% 0.0% 0.0% 0.0% 0.0%
CEM CRAZALL 0.2% 4.2% 0.1% 0.0% 13.5% 1.7% 0.7%
OTHERS CRAZALL 4.9% 4.6% 3.2% 5.4% 1.0% 12.3% 4.2%
CONS CRAZALL 0.0% 0.0% 0.0% 0.0% 0.0% 45.2% 50.9%
TRANS CRAZALL 87.9% 61.0% 16.9% 2.5% 5.1% 29.5% 32.3%
BIOG CRAZALL 0.0% 0.3% 39.7% 0.0% 0.0% 0.0% 0.0%
Total Total 100% 100% 100% 100% 100% 100% 100%


Within the transportation sector, the greatest contributor is off road vehicles and equipment (65%). Off-road vehicles and equipment include spark-ignition (gasoline) engines used in lawnmowers, chainsaws, light industrial machines, outboard motors and off-road recreational vehicles as well as compression ignition (diesel) engines used in construction, industrial, farm and forestry machines 3. Within upstream oil and gas, the greatest contributor is internal combustion equipment such as diesel generators and small combustion sources.


There are a number of municipal, provincial and federal initiatives that are in place to reduce NOx emissions. CRAZ’s Policy Committee has summarized many of these initiatives 4. In terms of transportation, some of the initiatives aimed at reducing emissions include increased carpooling, active transportation, fuel efficient driver education, purchase of fuel-efficient vehicles, and others. In terms of the upstream oil and gas sector, the federal government’s Multi Sector Air Pollution Regulation (MSAPR) targets NOx emissions.

CRAZ reviewed BC and Ontario’s programs aimed at reducing NOx emissions because, like CRAZ, the primary contributor of NOx and other CAC’s was transportation. These provinces developed programs to regulate vehicle emission testing. In Alberta many tools were proposed to address air quality issues stemming from transportation, including a similar vehicle emissions testing program. 5

CRAZ Air Quality Management Plan

To meet CRAZ’s objectives an Air Quality Management Plan (AQMP) 6 was developed in 2008. The AQMP is reviewed and adjusted every 3 to 5 years through stakeholder consultation. The AQMP identifies 6 objectives, and associated actions and steps to meet these objectives. Examples of a few of the objectives and associated actions and steps relevant to NOx reduction are provided below. Refer to reference 6 below to view the full AQMP.

  • Objective 2: Encourage strategic economic growth and foster sustainable business opportunities through improved understanding of air quality
    • Action 1: Incentives and deterrents will encourage area stakeholders to reduce emissions of air contaminants of concern. Step (ii) Support programs that promote emissions reduction from vehicles, lawnmowers, snowmobiles, etc. when available.
  • Objective 3: Regional land use planning will encourage and promote improvements in air quality
    • Action 2: Support multi- modal transportation systems. Step iii) Develop programs for municipalities that promote/incentivize positive air quality initiatives for transportation
  • Objective 4 – build and promote awareness of air quality issues
    • Action 2: Educate and outreach of regional stakeholders about area air emissions and reduction plans Step (vii) prepare the public for legislated changes such as anti-idling and tailpipe testing.

With the new CAAQS NO2 standards to be implemented in 2020, CRAZ contributes to initiatives aimed at reducing NOx by monitoring and communicating the ambient air quality, collaborating with stakeholders to share information, and develop strategies and actions to improve air quality.


References/ Further Information
1. CRAZ’s blog April 2019 “The New Canadian Standards for Ambient Air Quality Standards (CAAQS) for NO2” Part 1: Document Link
2. CRAZ Memo: Canadian Ambient Air Quality Standards (CAAQS) – Changes to Nitrogen Dioxide (NO2) Management Levels – Document Link
3. “Guide to Understanding the Canadian Environmental Protection Act: chapter 9” – Website Link
4. CRAZ Memo: Canadian Ambient Air Quality Standards (CAAQS) – Changes to Nitrogen Dioxide (NO2) Management Levels, Appendix B – Document Link
5. “Air Quality Management Policy Tools Leading Practice Research”, prepared by Markbek Resource Consultants in association with Amec Earth & Environment for Alberta Environment, Revised December 2007 – Website Link
6. CRAZ Air Quality Management Plan – Document Link

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