Government of New Brunswick

The equipment used in air quality monitoring has changed considerably since sampling and testing programs were first developed in the early 1970s. Air quality monitoring is now more technically demanding and requires skilled support to provide high quality results. There are essentially two types of monitoring: emissions and ambient.

Emissions Monitoring

Emissions monitoring ensures that facilities which are releasing pollutants to the air are within the limits established by provincial and national standards and guidelines.

Sources of air emissions that meet or exceed established criteria must obtain an Air Quality Approval which allows the facility to operate and establishes limits for emissions.

Emissions monitoring can include Continuous Emission Monitors (CEMs), opacity monitors which measure smoke density, noise monitoring, and fuel quality analysis. CEMs, for example, are able to analyze emissions at the source, around the clock, so prompt action can be taken by the facility if higher levels are detected. Government staff respond 24 hours a day to environmental emergencies reported by facilities.

Ambient Monitoring

Other monitors test the ambient air. This means the outdoor air around us. Ambient air quality reflects the releases of pollutants from both human activity and natural sources, as well as the effects of factors such as temperature, sunlight, air pressure, humidity, wind, rain, and landscape. Sometimes ambient monitors are placed near a source of emissions to help measure the impact of the source on the surrounding air.

Most air quality sampling units are designed to measure one substance. A sulphur dioxide monitor, for example, cannot sample for nitrogen oxide. Specialized devices are needed to test the air for each different substance.

The nature of the substance affects the type of reading that can be obtained, and the time it takes to do the testing. Gases such as ground-level ozone and carbon monoxide, for example, can be analyzed using "real-time" monitors that can generate raw data at the site and send it over telephone lines to a central computer. On the other hand, testing for Volatile Organic Compounds (VOCs) is done by pumping an air sample into a stainless steel cylinder at the monitoring site, then transporting it physically to a laboratory for detailed analysis.

Pollutants are often measured in extremely small concentrations, in "parts per million" (ppm) - think of one drop in a bathtub - or even in "parts per billion" (ppb). Not surprisingly, each monitoring unit needs regular maintenance and calibration or adjustment to produce the accurate results we need. The units themselves are costly to purchase and maintain.

Meanwhile, the demand for quick and easy-to-understand data continues to grow, as does the number and variety of substances in the air for which test results are needed.