"EPA's waiver of health standards is absolutely disgraceful," said Earthjustice attorney David Baron, who brought suit last year on behalf of the Sierra Club over the valley's air quality. "Instead of doing its job to protect public health, EPA is allowing thousands of people to be exposed to massive amounts of dangerous air pollution. EPA seems concerned more with protecting industry and agribusiness than with protecting the lungs of children in Imperial Valley."
Scientific studies link airborne particulates to tens of thousands of premature deaths nationally, as well as to reduced lung function and aggravation of lung disease. Airborne particulates consist of soot, soil, dust, metals, and other particles emitted by industrial facilities, agriculture operations, mines, motor vehicles, and other sources.
Imperial Valley violated health standards for airborne particulates on 206 days last year, according to EPA estimates. On one day last year, the area recorded particulate levels at 1000 percent more than the health standard – more than double the level at which EPA says people can be significantly harmed. The death rate from respiratory diseases in Imperial County is more than double that in California, according to the state's Department of Health Services.
EPA justified its action by claiming that Imperial Valley would meet standards if it weren't for air pollution coming from Mexico. But a detailed scientific study conducted for EPA in 1997 found that Imperial Valley would violate standards even without emissions from Mexico. The study showed that violations occurred miles north of the border even on days with stagnant air. "EPA chose to ignore its own study in favor of speculation by the state blaming Mexico for the violations," Baron said. "That's completely irresponsible, especially for an agency that claims to rely on 'sound science.'"
The Clean Air Act generally required attainment of particulate standards by 1994, and reclassification (or 'bump up') of areas missing that deadline to a more serious air pollution category. Reclassified areas must adopt stronger pollution controls for industry, agriculture, and other sources. Imperial Valley missed the 1994 deadline. After EPA failed for six years to bump up the area, Earthjustice sued on behalf of the Sierra Club to require action. EPA's waiver of the standard today also waives the bump up requirement.
Imperial County does not have an EPA-approved plan to address particulate pollution on the US side of the border, even though one was due ten years ago. "It's irresponsible for EPA to waive standards and point fingers at Mexico when the state hasn't cleaned up pollution on the US side," said Dr. Robert Palzer, chair of Sierra Club's air quality committee.
Earthjustice is considering a possible legal challenge to EPA's waiver of the clean air standard.
What is Particulate Matter (PM)?
Particulate matter, also known as "soot," is particles of dust, smoke, and haze that are released or kicked up into the air by vehicle travel on dirt roads, industrial crushing and grinding, and windblown dust. Burning fossil fuels, garbage, and agricultural products also releases soot into the air.
Soot can also be formed when chemicals (many of the same that form smog) react and condense in the atmosphere.
Soot is regulated based on the size of the particles. Current standards use ten microns as a standard, which is about one-seventh of the diameter of a human hair.
Levels of soot vary depending on rainfall and wind conditions.
Small particles are only regulated on a 24-hour and annual average, while large particles are regulated on an hourly basis.