Fresh air:  revolutionizing how to measure air quality

Where Alberta's rugged Rockies meet the endless prairie, the air tells a story. Knowing how to measure air quality here makes it a good story.

Every breath carries clues about industry, weather, ecosystems and human activity. Through air quality monitoring, those invisible signals are captured, measured and transformed into trusted environmental data.

Mastering Alberta's Air Quality Measurement with Integrated Sampling explores how a simple air sample becomes reliable, compliant environmental knowledge. From passive samplers to advanced canisters and analytical technologies, discover the tools and techniques used to understand the air around us.

Here, Mother Nature meets big data. Air is more than oxygen and nitrogen, it's a living record of a changing environment. Air quality monitoring reveals that story, blending science, technology, regulation and environmental stewardship to better understand the world we breathe.

This monitoring is outlined in a document called the Air Monitoring Directive (AMD), which has nine chapters.  The third section of Chapter 4 is covered in this article.  Here's the first part of Chapter 4.

Section 4, covering mobile air quality monitoring is provided in short form here.

The entire chapter can be seen in its official form here.

Overview of 3 - Integrated Sampling

Air cannot be brought back once it has drifted away. Integrated sampling captures a small piece of that moving atmosphere so it can be examined carefully in the laboratory.

Typical Albertan countryside showing our clean air

Sampling periods can range from a quick grab sample to 24-hour, monthly, or longer durations, depending on the contaminant and monitoring objective.

Short-term samples can capture pollution spikes, while long-term samples reveal trends.

When done correctly, integrated sampling turns air into actionable knowledge, providing the good data needed to assess and protect air quality.

To ensure reliable, compliant data:

• Use approved sampling equipment unless otherwise directed.
• Follow documented Standard Operating Procedures (SOPs) for setup, operation and maintenance.
• Where conflicts exist, regulatory requirements take precedence over manufacturer instructions.
• Protect samples from sunlight, contamination and improper storage during handling and transport.
• Maintain chain-of-custody documentation for every sample sent to a laboratory.
• Record key details on a field sheet, including location, sampling times and shipping information.
• Use a 24-hour clock and Mountain Standard Time for all records.
• Ensure laboratories follow recognized quality standards and fully document analytical methods.
• Apply quality flags to identify limitations or potential issues with results.

3.1 Passive Sampling

Passive samplers are often the first choice when the objective is understanding long-term spatial patterns across many locations because they allow dozens of sites to be monitored economically. They can monitor pollutants such as sulphur dioxide, hydrogen sulphide, nitrogen dioxide, ozone and VOCs. By collecting samples over time, passive samplers reveal both spatial patterns and long-term pollution trends.

One way how to measure air quality is through passive sampling.

Validation

Before use, passive samplers must be validated to demonstrate accuracy and precision under real-world conditions.

Validation compares sampler results against a reference method across a range of concentrations, weather conditions and sampling durations, typically over at least one year where seasonal variation is significant.

Revalidation is only required when the sampler, method, or application changes.

Installation

Accurate results depend on proper installation:

• Follow site-selection requirements and manufacturer instructions.
• Position samplers correctly.
• Keep diffusion barriers dry, clean and protected from wind.
• Use shelters that protect the sampler without affecting airflow or temperature.

Quality Control

To ensure defensible data:

• Deploy method blanks during every sampling period (minimum 10% of samples) to identify contamination.
• Deploy replicate samples (minimum 10%) to assess precision.
• Co-locate passive samplers with reference monitors where possible and compare results.
• Evaluate replicate and reference-method results to verify performance.

Sampling Period

Passive sampling relies on extended exposure periods:

• Monthly samples should be deployed for 30 ± 4 days.
• Other sampling periods should be within 10% of the specified duration unless otherwise approved.
• The sampler must be validated for the intended deployment period.

Determining Concentrations

Pollutant concentrations are calculated from:

• Sampling duration,
• Mass collected, and
• The sampler's sampling rate, determined through diffusion theory, laboratory testing, meteorological data, or integrative methods.

All calculations should follow approved procedures, use representative weather data where required and be fully documented.

The key to passive sampling is more than the laboratory analysis. It includes proper validation, deployment, documentation and quality control. When done correctly, passive samplers provide a cost-effective picture of air quality across time and space.

3.2 How to measure air quality with Intermittent Sampling

Intermittent sampling captures snapshots of air quality to measure dust, chemicals and metals. Sampling periods can range from a minute to a full day, making it useful for both short-term events and routine monitoring. Good results depend on using the right equipment, maintaining steady airflow and following manufacturer specifications for temperature, pressure and flow rate.

Analyze the air quality accurately

Filtration Sampling

Filtration samplers draw air through a filter to collect airborne particles such as dust, metals and particulate matter (TSP, PM₁₀ and PM₂.₅). Selecting the correct filter material, pore size and dimensions is critical. Airflow should be verified before and after sampling and detailed records of filters used and total air volume collected should be maintained.

Active Sorbent Sampling 

Active sorbent sampling uses a pump to pull air through a sorbent material that captures specific pollutants, such as VOCs. The sorbent must be matched to the target contaminant and a pre-filter may be used to remove particles that could interfere with sampling. Consistent airflow and careful documentation are essential for accurate results.

Canister Sampling

Often, investigators use canister sampling to capture short-duration events like odour complaints, process upsets or intermittent VOC releases that would likely be missed by monthly sampling. The canister fills under controlled vacuum conditions, preserving a representative air sample for laboratory testing. Proper canister preparation, pressure control, leak prevention and record keeping are critical to data quality.

Whether using filters, sorbents, or canisters, intermittent sampling turns brief moments of air into reliable environmental data, helping identify pollutants, track trends and support regulatory compliance.

3.3 Static Sampling

Static sampling is one of the oldest air quality monitoring techniques, operating without pumps, moving parts, or electricity. Historically used to track pollutants such as sulfur compounds and dustfall, it provided broad indications of air quality but lacks the accuracy and sensitivity of modern methods.

Today, passive and intermittent sampling have largely replaced static sampling and its use in Alberta is generally restricted to situations where specific approval has been granted.

Common historical applications included:

• Sulphur compound monitoring at oil and gas facilities.
• Dustfall monitoring at mines and industrial sites to measure settling dust.

While still recognized in some circumstances, static sampling is considered a legacy method because newer technologies provide better air quality data.

Like all monitoring methods, static sampling requires a defined sampling period to ensure results accurately represent the conditions being measured.

What to do next

Navigating Alberta's Air Monitoring Directive requires more than selecting the right equipment. Every sampling approach, whether integrated, passive, or intermittent, involves trade-offs between detection limits, averaging periods, logistics, cost and regulatory requirements. Choosing the right method from the start is critical to the success of any monitoring program.

Calvin Consulting Group Ltd. helps organizations meet AMD and EPEA requirements with expert guidance, audits, quality assurance and reporting support. Our services include:

• AMD compliance and audit assessments
• Air quality monitoring program reviews
• AMD Quality Assurance Plan development
• Environmental data quality assurance and reporting
• Technical support for integrated, passive and intermittent sampling programs

Our expert audits identify gaps, verify conformity and provide practical recommendations to strengthen monitoring and reporting programs.

At Calvin Consulting Group Ltd., we help you build monitoring programs that deliver accurate air quality data, supporting regulatory compliance, environmental stewardship and informed decision-making.

Contact Barry Lough:

...to learn how we can help you with how to measure air quality:  manage and protect the air your facility and neighbours depend on every day.

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Thank you to my research and writing assistants, and the author remains responsible for the content.

Check these before deploying passive samplers

□ Validation complete

□ Correct exposure period

□ Chain of custody ready

□ Method blanks prepared

□ Replicates scheduled

□ Weather records available