QUALITATIVE HUMAN HEALTH RISK ASSESSMENT
FOR AIRBORNE PARTICULATE MATTER AT THE HARRISON STREET PARK
Based on long-term air monitoring occurring over a 18 month period (from July 2001 to January 2003) at the Harrison Street Park in Berkeley, we conclude that PM10 (particulate matter less than 10 microns in size) concentrations are consistently higher than both State standards and regional background concentrations. The major source of this increased particulate concentration appears to be the City of Berkeley Solid Waste Transfer Station. These elevated concentrations are probably not a significant health risk for healthy individuals (adults or children) who spend a few hours a week at the Park. However, a number of epidemiology studies have shown that persons (particularly children) with preexisting respiratory illnesses are more sensitive to increased particulate concentrations as seen at the Park.
We would therefore recommend that the current health hazard communication posting (the Notice) remain in place with one change. This Notice currently advises Park users that "air quality at this site occasionally (our emphasis) does not net State standards. High particulate levels have an adverse health impact on children with respiratory problems. In addition, some health and safety experts suggest that existing state standards are inadequate to protect persons considered at risk. Should you have any questions, contact your doctor." We would recommend changing the word "occasionally" to "often" as this phrasing will better reflect the air monitoring data that shows over 100 daily exceedances of the 24 hour PM1O standard over the course of a year. We would also caution against moving children or adults with preexisting respiratory or cardiac illness into the proposed transitional housing next to the Park. These types of particulate exposures over an extended period of time could exacerbate existing conditions in both children and adults.
An 18 month air monitoring study (July 2001 through January 2003) was commissioned by the City of Berkeley to monitor airborne concentrations of particulate matter at the Harrison Street soccer field and park (the Park). The study undertaken was recently completed by Eric Winegar, Ph.D. of Applied Measurement Science. As part of the summary of the Applied Measurement Science air quality study, the City of Berkeley requested a qualitative human health risk assessment to look at potential health impacts from airborne particulate matter on users of the Harrison Street Park as well as on residents of the adjacent Ursula Sherman Village. Applied Measurement Science contracted with Dr. Charles Lambert of McDaniel Lambert Inc. to conduct the qualitative health risk assessment.
The Harrison Street Park is used as a recreational area for Berkeley residents. It is composed of two adjacent soccer fields and a skateboard park. The Park is mostly used in the late afternoon and early evening. Adjacent to the Park is the Ursula Sherman Village, a planned community designed to provide emergency and transitional housing, and social services for community residents. The Park is located in a primarily industrial area consisting of warehousing and manufacturing businesses.
The Park is exposed to potential ambient air pollutants from several local stationary and mobile sources. The stationary sources include, (1) the City of Berkeley Solid Waste Transfer Station directly south west across from the soccer fields; (2) the Recycling Center (0.15 miles south); and (3) the Berkeley Forge Company (0.25 miles south) and Pacific Steel Casting (EVEN CLOSER). The prevailing wind direction across the park is from the south to southwest, which is from the direction of the Transfer Station.
Mobile sources of air pollutants include, (1) freight and passenger trains along the adjacent Union Pacific right-of-way; (2) nearby Interstate 80 (0.20 miles south west); and (3) trucks moving in and out of the transfer station.
The users of the Park appear to be primarily soccer players who are at the Park in the late afternoon and early evening. The Park user at most potential risk is therefore a young child playing soccer on a regular basis at the Park. The average time spent by a child soccer player at the Park is approximately 4.5 hours per week and is based on three separate visits of 1.5 hours each (observations of City of Berkeley Staff). However, adjacent to the Park is transitional housing at the Ursula Sherman Village, where an adult population may live for a few months at a time. There are plans to expand the transitional housing, to allow families to stay for longer periods of time, up to two years. The populations of concern in this extended housing scenario would be young children, the elderly, and adults with preexisting respiratory illnesses.
One of the first air quality assessments in the Park area was conducted in 1997 by Acurex (Acurex 1997). This report was completed before the location was developed into a park and soccer fields. The assessment used both quantitative risk assessment and a qualitative approach to look at potential risk at the site from air pollution. The study concluded, based on a very limited air monitoring program, that the health risk from air pollution was "no more significant than is seen in a typical, densely-populated, urban environment" and that "the small particle value (PM 10), although higher than Normal Bay area ranges, is below the current National Ambient Air Quality Standards (NAAQS) and below the EPA's proposed standard for these materials".
Information gathered during the first year of the Applied Measurement Science air monitoring study were summarized and interpreted by Environ Corporation (Environ 2002a and b) in two reports prepared for Building Opportunities for Self-Sufficiency (BOSS). The Environ analysis was conducted to aid BOSS, which is planning to further develop the adjacent Ursula Sherman Village, a planned community that provides emergency and transitional housing, and social services for community residents. In their analysis of the airborne particulate air data, Environ concluded that, "PM 10 concentrations at the Harrison Street site appeared to be higher than at other Bay Area locations in 2002. Evaluations of available data clearly point to the West Berkeley Waste Transfer Station as the cause of elevated PM 10 concentrations at the site."
The results of Applied Measurement Science's air monitoring program show that air quality at the Park, particularly PM 10 concentration, is impacted by activities at the Transfer Station. This conclusion is in agreement with earlier conclusions reached by both Environ and Acurex. (Note: Acurex evaluation was just two days, which hardly constitutes an "air study") Based on these preliminary findings, a "Notice" was posted at the Park advising users that "air quality at this site occasionally does not meet State standards. High particulate levels have an adverse health impact on children with respiratory problems. In addition, some health and safety experts suggest that existing state standards are inadequate to protect persons considered at risk. Should you have any questions, contact your doctor."
Using the above data set a qualitative risk assessment was conducted comparing PM 10 annual averages with data from across the State, regulatory PM standard, and information from the health effects literature to draw conclusions about the safety of current users of the site. In the Table below, a summary of PM1O data from the California Air Resources Board database for various Bay Area locations as well as some locations in Southern California is provided for comparison purposes.
As can be seen from both of the above tables the annual average PM 10 concentration measured at the Park is significantly higher than local area background, other Bay Area communities, and is similar to concentrations seen in the more impacted areas of Southern California.
PM 10 is a heterogenous mix consisting of both fine particles (PM2.5 or particles less than 2.5 microns in diameter) and coarse particles (2.5 to 10 microns in diameter). PM 10 comes from a number of different sources, but the two major contributors are from combustion sources (e.g. fuel combustion, residential fireplaces, and agricultural burning) and from the transformation of gaseous pollutants (e.g. sulfur dioxide, nitrogen dioxides, and volatile organic compounds) in the atmosphere. Other sources of the coarser particles include windblown dust, unpaved roads, crushing and handling operations.
Acute health effects from PM 10 inhalation include an aggravation of bronchitis in adults and children with preexisting respiratory illness, small but significant changes in lung functioning in children, and immediate additional deaths of the elderly and of people with preexisting heart or lung disease if pollution levels are extremely high (e.g. London Fog of 1952) (Atkinson et al 1999; Peters et al 1999; McConnell et al 1999; Brenmer et al 1999). Asthmatics and those with allergies may also react to PM1O inhalation, particularly to sulfate particulates (Thurston 2000). Chronic exposure to PM1O may cause damage to lung tissues, contributing to chronic respiratory disease, cancer, and premature illness and death (Schwartz 2000). Symptoms of chronic obstructive pulmonary disease are correlated with ambient air particulate concentrations. Children in areas of higher particulate pollution seem to suffer from increased upper respiratory illnesses (e.g. colds, coughs) than do children in less polluted areas. There is some evidence to suggest that children in general may be more susceptible to the health effects of PM1O because of increased exposure (e.g. time outdoors, higher respiration rates) and other conditions (e.g. higher asthma rates, developing lungs) (Norris et al 1999; Thurston 2000; OEHHA/CARB 2000).
The present California Ambient Air Quality Standard (CAAQS) for PM1O is 50 ug/m3 for a sample gathered over a 24 hour period. The CAAQS for an annual arithmetic mean of 24 hour samples is 30 ug/m3 (a new standard of 20 ug/m3 is pending). The PM1O standards are often exceeded in various areas of the State, particularly Southern California. The CAAQ PM1O standards are set at these levels to "prevent excess deaths from short-term exposures and of exacerbation of symptoms in sensitive patients with respiratory disease. Prevention of excess seasonal declines in pulmonary function, especially in children". However, there is increasing epidemiological evidence that the threshold for health effects for sensitive populations (elderly with preexisting conditions, children) from PM1O may be below the current State standards of 30 ug/m3 (annual average) and 50 ug/m3 (24-hour average). There is currently no CAAQS for PM2.5, although a proposed annual arithmetic mean of 12 ug/m3 is pending.
The annual arithmetic concentrations of PM1O measured in the corner of the Park nearest the Transfer Station are high (46 ug/m3). This is evident from both a comparison to local background (34 ug/m3) and other regional background locations (e.g. Livermore at 24.6 ug/m3). The annual average for the Park is even higher than concentrations seen in an area with much worse regional air quality, namely the South Coast Basin (Los Angeles at 44.2 ug/m3). Moreover, the number of exceedances of the 24-hour State Standard at approximately 105 days/year exceed by four- fold the number for any other Bay Area location looked at in this comparison. The annual arithmetic concentrations of both PM 10 and PM2.5 at Harrison Park significantly exceed both existing and proposed CAAQ standards. The air quality, from a particulate perspective, is clearly poor at the Park, which has PM1O concentrations similar to some of the more impacted urban areas in the State.
For a healthy child who visits the Park a few times a week, exposure to these PM 10 concentrations is probably unlikely to cause health effects above those caused by background air pollution. The concern would be for an asthmatic child or child with other respiratory illness who uses the Park. Studies have shown that these children are more susceptible to elevated PM1O concentrations. If these children were engaging in recreational activities at the Park, with a likely increase in respiration rates, the possibility exists for an acute health episode (such as an asthmatic response) that is precipitated by the increased particulate concentrations at the Park. Similarly, this is probably not an ideal location for long-term housing (> six months) for families proposed by BOSS. If the residents were healthy adults it would probably not be a significant risk. However, adults or children with preexisting respiratory illness would probably be at increased risk of both acute and chronic respiratory illness.
Based on the above discussion and conclusions we would recommend that:
1) The current health hazard communication posting (the Notice) remain in place with one change. This Notice currently advises Park users that "air quality at this site occasionally (our emphasis) does not meet State standards. High particulate levels have an adverse health impact on children with respiratory problems. In addition, some health and safety experts suggest that existing state standards are inadequate to protect persons considered at risk. Should you have any questions, contact your doctor." We would recommend changing the word "occasionally" to "often" as this phrasing better reflects the air monitoring data that show over 100 daily exceedances of the 24 hour PM1O standard over the course of a year.
2) Caution is exercised with regard to moving children or adults with preexisting respiratory or cardiac illness into the proposed transitional housing next to the Park. These types of particulate exposures over an extended period of time could exacerbate existing conditions in both children and adults.
Is the air at Harrison Park unhealthful to breathe?
The particulate air quality at the Park is poor and it is probably unhealthful to be exposed to it for extended periods of time. Short-term exposure, such as a few hours per week, is unlikely to cause any health effects above those caused by area background particulate concentrations. However, children with preexisting respiratory illness (e.g. asthma) may be at increased risk of an acute health effect, such as an asthmatic response.
My child has asthma. What precautions should she take when playing at the Park?
It is hard to predict what may happen to an individual without knowing the particular health condition of your child. You should consult with your child's personal physician.
I have heard that young children, particularly children who are exercising outside, are more vulnerable to the health effects of particulate matter. Should we continue to let our children exercise and play at the Park?
There are some epidemiological studies that show that otherwise healthy children who live and play outside in areas where there are high concentration of PM1O may be at increased risk for suffering from respiratory health effects. In the Harrison Park situation, typical exposures are short term (a few hours a week). However, this is obviously a choice that each parent must make for themselves.
Are the residents at the homeless shelter at increased risk?
Most of the current adult residents are only at the shelter for brief stays. Unless they are suffering from a preexisting respiratory or cardiac illness that makes them particularly sensitive to increased concentrations of air particulates it is unlikely that their health will be affected.
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