Formaldehyde at Fremont School
This page last reviewed October 13, 2010
One of the important contributors to health risk, formaldehyde is a colorless gas at room temperature. The odor
is irritating and pungent. Limited human studies have reported an association between formaldehyde exposure and
lung and nasopharyngeal cancer. California has determined under Assembly Bill 1807 and Proposition 65 that formaldehyde
is a cancer-causing compound. Formaldehyde can also induce or exacerbate asthma. Vapors are highly irritating to
the eye and respiratory track. The ARB has taken regulatory actions to reduce formaldehyde emissions.
Formaldehyde is both directly emitted into the atmosphere and formed in the atmosphere as a result of photochemical reaction. The predominant sources of formaldehyde emissions are vehicle exhaust. Mobile sources contribute 85% and industry-related stationary sources contribute 15% of the statewide emissions. Naturally, formaldehyde occurs in forest fires, animal waste, microbial products of biological systems, and plant volatiles. It can also be formed in seawater by photochemical processes. Due to the adoption of the Air Resources Board's Low Emissions/Clean Fuels regulations, the formaldehyde emissions from cars and light-duty trucks are expected to decrease.
Ambient Monitoring Results
Ambient levels of formaldehyde are routinely monitored at approximately twenty sites in the California air toxics monitoring network. The statewide average concentration of formaldehyde during 1998-2001 was 2.9 ppb (parts per
billion), with values ranging from 0.05 ppb to 26 ppb. Relative to the statewide average, the Fresno region was
34% higher, with an average concentration of 3.9 ppb for the same time period.
The ambient monitoring results at Fremont School are provided here:
- A graph comparing the monthly summaries of formaldehyde at the community with historical statewide and regional levels
- A table of summary statistics
- Raw data in Excel format
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. Formaldehyde represents approximately 14% of the potential cancer risk of the nine measured compounds, excluding diesel particulate matter. Formaldehyde represents approximately 5% of the potential cancer risk of the nine measured compounds and the estimated diesel particulate matter.