What is Air Quality Monitoring?
Air quality monitoring refers to the process of measuring the types and amounts of pollutants in the air to assess the quality of the air we breathe. This involves using various sensors and devices to detect pollutants such as Particulate Matter (PM), Volatile Organic Compounds (VOCs), Carbon Monoxide (CO), Sulfur Dioxide (SO2), Nitrogen Dioxide (NO2), and Ozone (O3).
Purpose
Air quality monitoring aims to ensure that the air we breathe is safe for our health and well-being. This includes doing the following:
- Assessing pollution levels and trends to understand the impact of human activities on air quality.
- Providing timely information to the public about potential health risks associated with poor air quality that includes:
- Air Quality Index (AQI): A numerical scale from 0-500 to report daily air quality levels and forecast future conditions.
- Health advisories: Warnings that advise people to take necessary precautions based on the current level of air pollution.
- Evaluating the effectiveness of emissions control strategies in reducing pollution levels.
- Supporting regulatory compliance by monitoring and reporting on air quality standards set by international or government agencies.
Improve your EHS Management
Regulations on Air Quality
One purpose of air quality monitoring is to ensure the health and safety of individuals, so several regulations are in place to maintain safe air quality levels.
Global Context
The World Health Organization’s Air Quality Guidelines (AQG) are a set of recommendations for national, regional, and city governments on reducing the health impacts of air pollution. While countries are not legally required to follow these guidelines, they are meant to guide officials on how to provide cleaner air for all based on current scientific evidence. These suggestions also take into consideration the different needs and cultures of various countries and working environments, making them capable of supporting a wide range of policy options.
United States
Occupational Safety and Health Administration (OSHA)
OSHA has regulations that require employers to monitor indoor air quality to protect employees from poor air quality. Some key aspects include the following:
- Permissible Exposure Limits (PEL): OSHA establishes Permissible Exposure Limits (PELs) for airborne contaminants, defining maximum substance levels workers can encounter during a workday.
- Hazard Communication: Employers must communicate hazard information to employees using labels, Safety Data Sheets (SDS), and training programs.
Clean Air Act (CAA)
The CAA is a US environmental law enacted to control air pollution on a national level. It also authorizes the Environmental Protection Agency (EPA) to create and enforce standards to protect public health and the environment, such as:
- National Ambient Air Quality Standards (NAAQS): The CAA mandates the EPA to set NAAQS for six criteria pollutants: particulate matter, nitrogen dioxide, carbon monoxide, ground-level ozone, lead, and sulfur dioxide.
- State Implementation Plans (SIPs): The EPA requires states to develop and implement SIPs to ensure compliance with the NAAQS.
- New Source Review (NSR): This program ensures that new or modified sources of air pollution comply with the CAA’s emission standards.
- Regulation of Hazardous Air Pollutants: The CAA mandates the EPA to regulate toxic air pollutant emissions from industrial “source categories.” These pollutants include mercury, PCBs, benzene, and VOCs.
Key Pollutants Regulated
The table below shows the common pollutants regulated under the CAA and WHO:
Pollutant | CAA Regulation | WHO Guideline Level |
Particulate Matter | PM10, PM2.5 | PM2.5: 5 µg/m³ annually; 15 µg/m³ over 24 hours |
Nitrogen Dioxide | NO2 | 40 µg/m³ annually |
Sulfur Dioxide | SO2 | 20 µg/m³ over 24 hours |
Carbon Monoxide | CO | 4 mg/m³ over 8 hours |
Types
Various air quality monitoring solutions are available for indoor and outdoor environments to comply with these regulations and protect individuals’ health. For EPA’s regulations, there are two basic types of air quality monitoring systems:
- Ambient Air Quality Monitoring Systems: For measuring outdoor air quality in a specific area, typically with fixed monitoring stations to track pollutants.
- Stationary Source Emissions Monitoring: For monitoring emissions from fixed sources such as factories, power plants, and refineries.
Other methods used in air quality monitoring include:
- Satellite-based Monitoring: This method measures pollutants on a larger scale and obtain regional and global air quality data.
- Mobile Monitoring: This method uses vehicles equipped with air quality sensors to measure pollution levels across different locations. It helps cover large areas and identify pollution hotspots.
- Sensor-Based Monitoring: This method utilizes sensor-based devices that can be deployed widely to monitor air quality in various locations.
Explore SafetyCulture Monitoring Solution
Devices for Monitoring Air Quality
Here are some common types of air quality monitoring devices:
Indoor Air Quality (IAQ) Monitors
These devices measure air quality in indoor environments, such as homes, offices, schools, hospitals, and other buildings. They typically monitor pollutants such as VOCs, carbon dioxide, particulate matter (PM2.5 and PM10), and humidity levels.
Fixed Outdoor Air Quality Stations
These permanent installations continuously monitor air quality in a specific location, such as a city or industrial site. They can measure various pollutants, including PM10, PM2.5, ozone, nitrogen dioxide, and sulfur dioxide.
Carbon Dioxide (CO2) Monitors
These devices specifically measure the concentration of CO2 in the air. High levels of CO2 can indicate poor ventilation, which can cause health issues, especially in enclosed spaces.
Temperature and Humidity Sensors
While not directly measuring pollutants, these sensors provide essential context for air quality assessments, as temperature and humidity can affect pollutant levels and human comfort.
FAQs about Air Quality Monitoring
Hurricanes and wildfires have distinct effects on air quality. Hurricanes can temporarily elevate air pollution levels by spreading pollutants and debris through high winds. In contrast, wildfires severely degrade air quality by emitting significant amounts of particulate matter and gasses, such as carbon monoxide and VOCs, into the atmosphere.
Both events can also contribute to the formation of ozone, a harmful pollutant. Monitoring air quality during these occurrences is crucial, and taking necessary precautions is essential to safeguard public health.
Most standard air quality monitors do not directly detect mold. However, they can measure indicators such as humidity and particulate matter, which may suggest mold presence. Specific mold testing kits and professionals may be needed to identify and accurately measure mold levels in indoor air.