Air Pollution and the Clean Air Act

Air Pollution: Air Quality & Monitoring

• Air quality is a dynamic and complex environmental phenomenon that exhibits large temporal and spatial variation.
• Variations in atmospheric pollution levels are caused by changes in pollutant source emission rates, and changes in meteorology and topography.
• These changes influence chemical reactions in the atmosphere and the control/removal of atmospheric pollutants.

Clean Air Act (CAA)

• The Environmental Protection Agency (EPA) defines ambient air as the portion of the atmosphere external to buildings, accessible to the public.
• The CAA regulates pollution entering the outside air. This includes emissions from stacks, chimneys, vents, and equivalent openings (point sources) or area sources based on size.
• The CAA also regulates mobile and fugitive emissions directly released into the atmosphere.
• Indoor air pollution and pollution confined to private property (e.g., workplace emissions) are not regulated by the CAA.

National Ambient Air Quality Standards (NAAQS)

• The EPA establishes NAAQS for pollutants designated as "criteria" pollutants.
• Six criteria air pollutants are: ozone, particulate matter (PM10 and PM2.5), sulfur oxides, carbon monoxide, nitrogen dioxide, and lead.
• Ozone is formed by the interaction of volatile organic compounds (VOCs) and nitrogen oxides (NOx) in the presence of sunlight.
• A standard's value depends heavily on the time period over which measurements are averaged.

Types of NAAQS

• Primary standards: These are "health-based" standards to protect human health and the environment, targeting vulnerable populations like children, the elderly, and asthmatics.
• Secondary standards: Designed to safeguard public welfare and prevent damage to public property (animals, plants, and property).
• Both primary and secondary NAAQS define the maximum permissible concentrations of these pollutants in ambient air.

NAAQS (Primary & Secondary) Details

• The table provides specific primary and secondary standards for various pollutants (CO, Pb, NO₂, O₃, PM₁₀, PM₂.₅, SO₂).
• Each pollutant has varying averaging times and maximum concentration limits.

Air Monitoring

• Air quality monitoring is complex, requiring data collection to understand the dynamic nature of air quality's spatial and temporal variations.
• Ambient air quality monitoring is a systematic, long-term assessment of air pollutant levels in communities.
• This monitoring is commonly used to characterize urban areas, near large point pollution sources, or areas with sensitive environmental receptors.

Stationary Monitoring

• A stationary monitoring network provides data for:
  • Background concentration levels
  • Highest concentration levels in high-density areas
  • Impact of local and remote pollution source
  • Relative impact of natural and anthropogenic (human-caused) sources
• Various spatial scales (microscale, middle scale, neighborhood, urban, and regional) are defined for different monitoring objectives.

Mobile Monitoring

• Mobile monitoring uses platforms like aircraft or vehicles to monitor air quality.
• This process tracks atmospheric transport and chemical transformations occurring between the source and the receptor.
• It also helps understand photochemical smog, acidic deposition, and air pollutant dispersion from sources.
• Hotspots, areas suspected of elevated pollutant concentrations, are another important focus of mobile monitoring. Nearby locations, unfavorable meteorological conditions, or incidents (chemical spills, nuclear/chemical accidents) are often targeted.

Air Quality in Jordan

• Air quality in Jordan is frequently a problem, especially in low-lying areas and areas with high traffic density.
• Major sources of pollutants in Jordan are vehicles, industries, and residential activities.
• Specific data from 2004 show vehicle transportation as a major source (79% for NOₓ, 39% for TSP), with further breakdowns of other sources including industries (and their breakdowns in different pollutant contributions).
• Vehicle fleets in Jordan are often older models, and are a major air pollution contributor.
• Industrial emission hotspots include cement plants, power plants, and mining activities.

Additional Details

• Detailed tables provide pollutant emission sources and monitoring institution locations in several Jordanian areas, along with data on pollutants (SO₂, NOx, CO, PM10), monitoring frequency, and monitoring stations.