Guide to: Air Watch Bay Area

Last Updated: 2017-08-11

The Air Watch Bay Area website and reporting app are digital tools to reveal and act on air pollution in the San Francisco Bay Area, focusing on community air quality near the region’s five oil refineries.

Please email us at if you have any further questions about the site!

Table of Contents:

How to View Air Quality

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From the “Air Quality” tab, choose a community (Richmond, Crockett-Rodeo, or Benicia), and then choose a monitor on the map to view a graph of chemical levels at that location.

Pollutant Information

Health Limits at a Glance

There are many different health limits set by different agencies for each pollutant and it can be difficult to decide which standards to use. The Air Watch Bay Area website has chosen to the health limits that are the most protective, and therefore uses numbers from multiple agencies. We also highlight the chronic levels of pollutants since many people using this site are typically exposed to these pollutants for extended periods of time.  



Benzene is an aromatic hydrocarbon arranged in a ring structure, with 6 carbons and alternating double bond s. It is a volatile liquid substance that is used in chemical synthesis and can be found in both coal and petroleum. There are multiple acute health effects related to exposure of Benzene including moderate eye and skin irritation, headache, dizziness, drowsiness, confusion, and tremors. Longer term effects can include aplastic anemia as well as cancers such as lymphocytic leukemia, non-Hodgkin’s lymphoma, myeloid leukemia, as well as others. According to the California Office of Environmental Health Hazard Assessment (OEHHA) the chronic health limit for benzene is 1 part per billion over an 8-hour period.



Toluene is a substance that is naturally occurring in crude oil and is used to make such substances as plastics, rubbers, and paints as well as others. It can lead to acute symptoms affecting the central nervous system such as irritation of the eyes and nose, confusion, headache, anxiety, dizziness, and insomnia. More serious symptoms include kidney and liver damage as well as having links to reproductive difficulties. The current suggested chronic health limit by the California Office of Environmental Health Hazard Assessment (OEHHA) is 70 parts per billion.



Ethylbenzene is found in coal tar and petroleum as well as gasoline and paints. Exposure to high levels for a short period can lead to eye and throat irritation and even higher levels can cause dizziness. Long periods of low exposure can cause kidney damage as well as possible irreversible inner ear damage. Research by the International Agency for Research on Cancer has named ethylbenzene as a possible carcinogen. The Agency for Toxic Substances and Disease Registry (ATSDR) have set the chronic health limit at 60 parts per billion.



Xylene is a naturally occurring substance in petroleum and tar and is frequently used as a solvent in the printing, rubber, and leather industries. Exposure to high levels for a short or long period of time can cause headache, lack of coordination, confusion, and dizziness. Higher levels of exposure for a shorter period can cause skin, eye, nose, and throat irritation as well as difficulty breathing, lung issues, difficulty with memory, and changes in liver and kidney function. The current chronic health limit set by the Agency for Toxic Substances and Disease Registry (ATSDR) is set at 50 parts per billion.


Black Carbon

Black Carbon is a major component of particulate matter that occurs from incomplete combustion of fuels, biofuels, and biomass. The health effects of black carbon are not yet agreed upon in the scientific community but it is thought that they lead to an increase of asthmatic incidents and respiratory episodes as well as cardiovascular issues and visits to the emergency room. The current chronic health limit is 5 μg/m3 according to the California Office of Environmental Health Hazard Assessment (OEHHA).  


Hydrogen Sulfide

Hydrogen sulfide is easily identifiable by its rotten egg smell, and it naturally occurs in crude petroleum and natural gas. Short term effects include odor, nausea, tearing of the eyes, headaches, insomnia, respiratory problems, digestive upset, and fatigue. Longer term issues are chronic headaches, poor attention span and memory, cardiovascular issues, and asthma. The chronic health limit set by the California Office of Environmental Health Hazard Assessment (OEHHA) is 8 parts per billion


Sulfur Dioxide

Sulfur dioxide comes from the combustion of coal and oil at industrial plants as well as from copper smelting. Short term exposure can cause respiratory issues and burning of the nose and throat. Longer term symptoms of exposure are decreased lung function and chronic asthma. Sulfur Dioxide is one of the Environmental Protection Agency’s 6 criteria pollutants which means there are National Ambient Air Quality Standards (NAAQS) that are reassessed every 5 years. Currently the health limit is at 75 parts per billion over a 1-hour period.


Particulate Matter

Particulate matter is particles and liquid droplets that are in the air, some coming directly from the source and some from complex reactions of chemicals through industrial processes. The most dangerous type of particulate matter for health is PM 2.5, or fine particles, because they are small enough to be absorbed deep inside the lungs. Once particulate matter is inhaled, it can cause irritation of the lungs and aggravation of chronic lung diseases. Particulate matter can also impact heart function, changes in blood chemistry that can result in clots that lead to heart attacks, and increased susceptibility to viruses and bacterial infections that can lead to pneumonia in sensitive populations. The health limit for PM 2.5 is 35 μg/m3 over a 24-hour period and for PM 10 is 150 μg/m3 over a 24 hour period, both according to the National Ambient Air Quality Standards (NAAQS).

How to Report a Pollution Incident

From the “Report Pollution” tab:

Click on the appropriate type of pollution incident, rate odors, describe any health symptoms, and upload associated photos.

Note that the location field is required, so please enter a location in the form of an address or cross street. Suggestions will load underneath the location field to help you out. A red line appears around required items that have not been filled out:

By reporting a pollution incident, you contribute to a publicly visible “paper trail” on the Air Watch Bay Area website. You can also click to report any incidents to the Bay Area Air Quality Management District (BAAQMD).

How to View User Reports

Click on the User Reports tab to see the pollution incidents that others have shared.  

Sort the reports by choosing an option from the dropdown menu:


And filter results by choosing one of the categories listed.