1,3-Butadiene at Memorial Academy
This page last reviewed October 21, 2010
Background
One of the important contributors to health risk, 1,3-butadiene is a flammable, colorless gas with a pungent, aromatic,
gasoline-like odor. 1,3-butadiene vapors are mildly irritating to the eyes and mucous membranes. They can cause
neurological effects such as blurred vision, fatigue, headache, and vertigo at very high levels. The ARB has identified
1,3-butadiene as a toxic air contaminant based on its potential to cause cancer. California has determined under
Assembly Bill 1807 and Proposition 65 that 1,3-butadiene is a cancer-causing compound.
In California, the majority of emissions are from incomplete combustion of gasoline and diesel fuels. Mobile sources
account for approximately 96% of the total annual emissions statewide for quantified sources. The primary stationary
sources of emissions are petroleum refining, manufacturing of synthetics and man-made materials, and oil and gas
extraction. In nature, 1,3-butadiene is emitted as a product of incomplete combustion during forest fires. 1,3-butadiene
emissions have been reduced in California through motor vehicle emission control regulations and the introduction
of cleaner burning gasoline. In the1990s, the ambient 1,3-butadiene levels showed a steady downward trend, based
on the statewide annual average. The 2000 statewide ambient 1,3-butadiene concentration was approximately 53% lower
than that in 1990.
Ambient Monitoring Results
Ambient levels of 1,3-butadiene are routinely monitored at approximately twenty sites in the California air toxics
monitoring network. The statewide average concentration of 1,3-butadiene during 1998-2000 was 0.2 ppb (parts per
billion), with values ranging from 0.1 ppb to 3.0 ppb. Relative to the statewide average, the San Diego region
was 12% lower for the same time period.
The ambient monitoring results at Memorial Academy are provided here:
- A graph comparing the monthly summaries of 1,3-butadiene at Memorial Academy with historical statewide and regional levels
- A table of summary statistics
- Raw data in Excel format
Cancer Risk
Cancer risk is the number of excess cancer cases among a million people if the people are exposed to levels of a toxic air pollutant over 70 years. Nine measured compounds, which do not include diesel particulate matter, make up most of the estimated cancer risk at Memorial Academy. 1,3-butadiene represents approximately 38% of the cancer risk of the nine measured compounds.
