Chevron Fire and Air Quality in the East Bay

On the evening of August 6, 2012 a fire broke out at the Chevron Refinery in Richmond, CA. The fire began in a crude oil unit, where there was a leak and was contained that evening, but a small controlled burn was allowed to reduce pressure in the system. Area residents were told to stay inside with windows closed for more than five hours before the all clear was given by the Contra Costa County Health Department.

The Bay Area Air Quality Management District (Air District) responded to the emergency and took eight air samples during the fire. After analysis of the samples for 23 chemical compounds the Air District reported that they found only acrolein levels above the Reference Exposure Level, REL. The Air District noted that throughout the Bay Area acrolein levels are commonly above the REL (not exactly comforting). Reportedly, acrolein levels routinely range between 1 and 4.5 parts per billion. The Air District stated in their news release that “(t)hese concentrations were similar to the “background” levels measured throughout the Bay Area by our monitoring network.”

While this sounds comforting this report by the Air District can be misleading. First of all the data is incomplete and second there are three types of REL, Acute (1 hour exposure), 8 hour (which may be repeated) and chronic. When the Air District spoke of REL they were referring to the acute level, not normal everyday background levels. According to Cal EPA “The acute REL is an exposure that is not likely to cause adverse effects in a human population, including sensitive subgroups, exposed to that concentration for one hour on an intermittent basis.” These health based acute RELs apply to spills, leaks, or other discharges to the ambient air that results from routine operation of a facility and predictable process upsets or leaks.”

Cal EPA determined the concentration level at which no adverse health effects are anticipated for a short term. The acute RELs are based on the most sensitive populations reporting of adverse health effects in the medical and toxicological literature. RELs are designed to protect the most sensitive individuals in the population by the inclusion of margins of safety. Margins of safety are incorporated into the REL to address data gaps and uncertainties, exceeding the REL does not automatically indicate an adverse health impact. The acute REL was the “background” levels that the Air District referred to. More importantly, the data from the Air District is not yet complete. There was no measurement of particulates.

According to reports in the San Francisco Chronicle there was a huge cloud of smoke and hundreds of people went to the hospital to seek treatment. The most likely source of health impacts from the fire is particulate matter from smoke. The Air District does not yet have any data to release on particulate concentrations downwind from the Chevron refinery. For some reason the stationary continuous particulate monitors for the Air District in the local area are upwind of the refinery. The Air District says samples were taken in San Pablo, two miles from the Chevron facility following the fire and are being analyzed for particulate matter levels. Results are expected in the next two weeks, but there is only a small chance that the regularly scheduled monitoring time will have caught the smoke cloud.

Particulate matter is made up of particles that are emitted directly, such as soot and dust, as well as secondary particles that are formed in the atmosphere from reactions of precursor pollutants such as oxides of nitrogen (NOx), sulfur oxides (SOx), volatile organic compounds (VOCs), and ammonia (NH3). Particle are either directly emitted or formed in the atmosphere. Directly-emitted particles come from a variety of sources such as cars, trucks, buses, industrial facilities, power plants, construction sites, tilled fields, unpaved roads, stone crushing, and burning of wood. Other particles are formed indirectly when gases produced by fossil fuel combustion react with sunlight and water vapor. Many combustion sources, such as motor vehicles, power plants, and refineries both emit particles directly and emit precursor pollutants that form secondary particulates. Ammonium nitrate and ammonium sulfate are the principal components of secondary particulates.

Particulate matter has immediate health impacts: itchy, watery eyes, increased respiratory symptoms such as irritation of the airways, coughing or difficulty breathing and aggravated asthma. Health effects can result from both short-term and long-term exposure to particulate pollution. Exposure to particles can also trigger heart attacks and cause premature death in people with pre-existing cardiac or respiratory disease. People most sensitive to particulate pollution include infants and children, the elderly, and persons with existing heart and lung disease. The particles can travel deep into the lungs, enter the bloodstream, and penetrate into cells. Smaller particles can penetrate deepest, causing the greatest harm. Researchers are still trying to identify which types and sources of particles are most hazardous to human health. Though, particles created from combustion soot tend to be fine particles with diameters smaller than 2.5 microns (PM 2.5) which are the most dangerous because it lodges in the lungs. Dust is mostly coarser particles.

According to the Lung Association, the two biggest air pollution threats in the United States are ozone and particle pollution. The United States Environmental Protection Agency, U.S. EPA requires states to monitor air pollution to assess the healthfulness of air quality and ensure that they meet minimum air quality standards. The US EPA has established both annual and 24-hour PM2.5 air quality standards (as well as standards for other pollutants). The annual standard is currently 15 ug/m3 (an AQI of 49). The 24-hr standard was recently revised to a level of 35 ug/m3 (an AQI of 99). The EPA is proposing new air quality particulate standards to go into effect in December 2012. The proposed annual average particle pollution will be lowered to 12-13 ug/m3. The maximum 24 hour standard will remain unchanged at 35 ug/m3. The Bay Area Air District does not have a live feed for their particulate pollution levels like some regions of the state.

The Bay Area's cool, coastal climate safeguards the region against some factors that exacerbate pollution, such as high temperatures and stagnant air flow. Nonetheless, the Bay Area is a nonattainment area due to persistent smog. Santa Clara, Solano and Contra Costa counties had more than 12 high particle pollution days last year of record. A study of children in Southern California showed lung damage associated with long-term particulate exposure, and a multi-city study found decreased lung function in children associated with long term particulate exposure. Many scientific studies have linked exposure to excess particulates to aggravated asthma, increased respiratory symptoms like coughing and difficult or painful breathing, chronic bronchitis, decreased lung function, heart attack and premature death. According to American Lung Association State of the Air Report, Pittsburgh, PA had the highest particle pollution in the nation on an annual basis and Bakersfield, CA had the highest number of days exceeding the daily level. Seven cities averaged particulate levels higher than the 15 ug/m3 current standard allows: Bakersfield, CA; Hanford, CA; Los Angeles, CA; Visalia, CA; Fresno, CA; Pittsburgh, PA; and Phoenix, AZ.

Beijing and Bakersfield Air Quality Problems

Air pollution is once more in the news. The Chinese announced that they will begin publishing the small particle, PM2.5 air pollution data for Beijing after January 23rd. Beijing, has been reporting their air quality based on PM10, which are particles smaller than 10 micrometers but larger than 2.5 micrometers in diameter. It has not reported particulate pollution of 2.5 micrometers or less. Combustion engines and coal burning power plants are key contributors to PM2.5 particles, and according to the US EPA and World Health Organization, the smaller, finer pollutants measured by PM2.5 are especially dangerous for human health. Studies have shown that people increased risk of asthma, lung cancer, cardiovascular problems, birth defects and premature death from particles smaller than 2.5 microns in diameter that lodge deep in the lungs.

Despite the official Chinese government report of 286 “blue sky” days last year, the air pollution in Beijing, home to over 20 million people, is easily seen by the smog that wraps the city’s apartment complexes and office buildings many days and by non-government sanctioned reports. The US Embassy in Beijing has their own PM2.5 monitoring station atop their building and has been reporting via an open Embassy Twitter Feed hourly PM2.5 pollution data to the chagrin of the Chinese government because it conflicted with official government data. The U.S. Embassy reported a series of readings beyond the scale of the air quality index, AQI, (which goes to 500) in fall of 2010 and levels over 300 this past fall which sparked a public campaign (over the internet) for better government reporting. Current air quality levels from the US Embassy are 325 which is “hazardous” according to the EPA.

In the United States, the Air Pollution Control District for Bakersfield, California, the city ranked by the American Lung Association as having the worst particulate matter (PM2.5) air pollution in the United States for the last several years, announced they had the worst air quality December recorded in over a decade. The area has already had four times as many unhealthy days this season than in the entire 2010-2011 winter season. In Bakersfield and the rest of the San Joaquin Valley PM2.5 concentrations are highest when cool stable weather and low wind speeds coupled with the Valley’s topography limit dispersion of pollutants and allow multi-day buildups of PM2.5 concentrations to occur along with the “Tule” fog which forms during this time of year. A lingering high-pressure system and dry La Nina conditions in the Pacific have created stagnant air in the valley. As a result car exhaust, agricultural emission and smoke from factories and chimneys has remained in place and this morning’s reading on the San Joaquin Valley Air Pollution Control District was 25 ug/m3 at Bakersfield with an AQI of 74 which is “moderate” air quality.

According to the Lung Association, the two biggest air pollution threats in the United States are ozone and particle pollution. Other pollutants include carbon monoxide, lead, nitrogen dioxide, sulfur dioxide and a variety of toxic substances including mercury that appear in smaller quantities. The United States Environmental Protection Agency, U.S. EPA, requires states to monitor air pollution to assess the healthfulness of air quality and ensure that they meet minimum air quality standards. The US EPA has established both annual and 24-hour PM2.5 air quality standards (as well as standards for other pollutants). The annual standard is 15 ug/m3 (an AQI of 49). The 24-hr standard was recently revised to a level of 35 ug/m3 (an AQI of 99). The recently challenged, Cross-State Air Pollution Rule (CSAPR) was intended in part to prevent pollution from one state from moving into other states and preventing them from meeting their goals, but the problems in the San Joaquin Valley are caused by local industry, the weather and the Sierra Nevada mountains to the east and the Coastal Range mountains to the west that wall the valley. The World Health Organization guidelines for PM2.5 are based on a mean level rather than the average that the U.S. EPA uses.

PM2.5 particles can be either directly emitted or formed via atmospheric reactions. Primary particles are emitted from cars, trucks, and heavy equipment, as well as residential wood combustion, forest fires, and agricultural waste burning. The main components of secondary particulate matter are formed when pollutants like NOx and SO2 react in the atmosphere to form particles. In the San Joaquin Valley the primary source of secondary particles are ammonium nitrate and ammonium sulfate which forms when nitrogen oxide and sulfur dioxide emissions from cars, trucks, and industrial facilities react with ammonia from agricultural operations.

Bakersfield, at the southern end of the San Joaquin Valley with a population of about 350,000 has some of the worst air in the United States. The city’s economy relies on agriculture, petroleum extraction and refining, and manufacturing. Cutting through the valley are the state's two main north-south highway corridors, the routes for nearly all long-distance tractor trailer rigs, the No. 2 source of particulate pollution in the valley. Also in the mix are millions of acres of plowed farmland and 1.6 million dairy cows and ammonia-laden manure they create. Without wind and rain, when the Tule fog forms, the air sits, trapped as if in a pot with a lid. With an air quality index a fraction of the level in Beijing local groups in Bakersfield have condemned the failure of the Air Quality Control Board to meet the federal standard by banning wood burning as the easiest source of particulate pollution that is easy to ban, but even with the ban in place for most of December, air quality remained at unhealthy levels with AQI over 100, but air quality has improved over the weekend.