I am currently employed by the California Air Resources Board (CARB) as an Air Pollution Specialist. I am the lead person for the PM10 program. PM10 is an abbreviation for Particulate Matter of 10 microns in diameter and less. These are small particles in the air that can be inhaled and lead to adverse health effects such as increased asthma rates, respiratory disease, heart disease, and more. PM10 in our air comes from many sources including natural airborne dust, fugitive dust from farming operations and building sites, diesel soot, auto exhaust, emmisions from industry, and many more. The ARB's mission is to protect the public health by minimizing the exposure of citizens to harmful air contaminants such as PM10. There are many different branches of the ARB that handle various parts of this process; lawmaking, regulation enforcement, research, etc. I work for the Monitoring and Laboratory Division. Our responsibility is to measure pollutants in the air on a regular basis. By knowing what the concentration of pollutants in the air is, we can determine how well our regulations are working, and determine if and where more needs to be done. The premise for the PM10 program is really quite simple. We have large filters made out of quartz that are supplied to us by the EPA. We inspect the filters for any defects, and if they pass our inspection we weigh the filters and send them out to our sampling sites. We send out filters to 68 sites located throughout California. Do I analyze the PM10 samples for a site near you? Check this interactive map. When the filters arrive at the sampling sites they are loaded into a sampler. The samplers draw in air, run the air through a sort of obstacle course that excludes all the particulate matter except fo the small stuff we're interested in, and then pulls that air through our filter. This way only the PM10, and not larger particles, are deposited on the filter. The filter is then shipped back to the ARB where we weigh it again. The difference between the weight before and after sampling is determined, and this is used to calculate the concentration of PM10 in the air. The details of what we do and how we do it are laid out in our Standard Operating Procedure (SOP) for the method. One of the more rewarding aspects of my job is that I get to paticipate in special studies. Special studies are everything from long-term studies that we perform in order to learn more about air pollution to very short term studies that we perform when there is an environmental disaster. Here are some special studies that I have been involved in:     The Barrio Logan Study Barrio Logan is an impoverished area of San Diego that has mixed land use. That is to say that there are houses and businesses side-by-side. In 2001 we performed a study to see if this mixed land use was having an impact on the health of the residents. We were suprised to find hexavalent chromium (a very potent carcinogen) in the air at concentrations up to 175 times the national average. More comprehensive monitoring of the area in 2002 eventually traced the source of this pollution to a chrome plating facility. Although they were following laws in the way that they were conducting their business, nearby residents were clearly being exposed to unacceptable levels of hexavalent chromium. A court order shut the business down, and the data we generated was used to justify new regulations on the chrome plating industry so that residents throughout the state living near chrome plating facilities would be protected as well. For more information of the study see the ARB's official webpage on the Barrio Logan study.     The Nipomo Mesa Special Study Nipomo mesa is an area in Southern California inhabited by about 12,000 people. Historically they have problems there with high concentrations of particulate matter. As a result we conducted a rather intensive year-long study in 2004. We did determine that Nipomo Mesa has a chronic problem with high particulate levels. The primary source of the pollution turned out to be... dust. Strong winds coming off the ocean were picking up dust and blowing it into the area. Unfortunately, this meant that we could do very little to improve the health of the residents of Nipomo Mesa. The only step we determined could be taken to significantly lessen particulate pollution in the area was to pave some high-traffic dirt roads. It is also speculated that a nearby off-road recreation area may kick up significant quantities of dust and contribute to the high levels, but our results pertaining to that were inconclusive. See the published report on the study if you want more details.     Westley Tire Fire On September 22, 1999 lightning struck a tire storage facility in Westly, CA. An estimated 7 million tires were being stored there. The fire took 30 days and $3.5 million to put out. At the time of this event I was responsible for analyzing Non-Methane Organic Carbon (NMOC) compounds. Air samples were taken and I analyzed them for 69 different compounds.     Train Trestle Fire On March 15, 2007 a 300 foot long stretch of a train trestle caught fire in Sacramento, CA. The emergency response team sprang into action and began monitoring the air quality to make sure that residents weren’t being exposed to unacceptable levels of pollution. For my part of this response I measured the PM10 levels in nearby Roseville. The fire was put out relatively quickly, and its cause is currently under investigation.