West Berkeley Air Monitoring Part 2 or return to: West Berkeley Air Monitoring Part 1
Eric D. Winegar, Ph.D., Q.E.P. Applied Measurement Science
September 6, 2000

These data show that a wide range of volatile organic compounds were present in the atmosphere during these sampling events. There are several notable compounds. First, acrolein is present at levels ranging from 0.9 to 7.5 ppbv. This compound is a high risk driver for areas that are exposed to vehicular exhaust, both automotive and diesel. The highest concentration was detected at the Kaiser sampling location, but on Saturday, June 17 when the vehicular levels were low as measured by the other exhaust parameters. The next highest level was on June 14, the stagnant polluted day. The concentration range that was detected suggests a high hazard index, which is a measure of non-carcinogenic health effects.

BTEX was detected at moderate levels also, and may be of concern from the carcinogenic health effects. Several other compounds are indicative of automotive exhaust. For example, 1,2,4-trimethyl benzene is strongly associated with automotive sources.

1,4-Dioxane was detected at a high level on two days, one of which was detected at 33 ppbv, which suggests a nearby source. The source is unknown.

As has been the case with the other target parameters, the concentrations are higher for Wednesday, June 14, and lower for the Luten and second Marina samples.

For the samples collected at Dicon, there is evidence of solvent or industrial use. For example, methyl ethyl ketone, acetone, ethanol, and methylene chloride were all detected at levels indicative of local emissions. In addition, carbon disulfide was detected at a moderate level on June 14 when the sampling point was near several industrial facilities.

Two freons were detected at levels representative of general background concentrations. The similarity of these concentrations between samples indicates good internal consistency in the sampling and analysis procedures. The mixture of compounds detected was not indicative of an odorous source, although some unknown additive effects may come into play. Odors were detected at the Dicon site on June 14, and as is seen in the data tables, the concentration levels for many compounds were high. Residents and visitors have complained of a particular odor in the West Berkeley area, downwind of the industries, but no particular compound shows up as indicative of a specific odor. It is probable that the mixture of these compounds cause additive effects, some of which are known to push the odor threshold lower so that even low trace levels would be detectable. However, this sampling data set is limited in its capability to elucidate the odor problem.

Aldehydes and Ketones

The aldehyde and ketone data presented some notable concentrations of a number of pollutants. The concentration of formaldehyde on June 14 was extremely high-149.3 ppbv. This concentration level is sufficient to cause eye and lung irritation. Other aldehydes and ketones were detected at elevated levels on that also. Table 11 contains the data for all the sampling sites, and Figure 11 shows a graphic representation of the summation of the pollutant concentrations for each of the sampling days.

Table 11. Aldehydes and Ketones

Figure 11. Sum of Aldehyde and Ketones

The data for the Goodyear sampling location also showed high levels of several compounds. Most of these compounds are reflective of combustion sources, although some of the higher aldehydes may be associated with biogenic activities. In addition, some of these compounds may be the result of photochemical activity, which would explain the high levels under the stagnant June 14 conditions.

Some of these compounds may be associated with odors that have been detectable in the West Berkeley area, downwind of the industrial facilities.

SVOCs

Table 12 contains the list of semivolatile organic compounds. All units are in micrograms per cubic meter.

Table 12. Semivolatile Organic Compounds (ug/m3)

The large number of compounds detected is representative of an urban atmosphere. The breadth of the detected chemicals and the limited number of samples challenges the ability to draw complete conclusions from this data set. However, some limited conclusions can be drawn. First, the data from June 14 fits in with the other parameters for pollution event. The concentrations of some combustion derived compounds are consistent with their location and the density of vehicular exhaust.

For example, dibenzofuran was present in all samples, with the concentrations highest on the June 14 pollution event, but also higher at the Goodyear location downtown. The levels adjacent to 1-80 were relatively lower. And although other pollutants were present at higher levels on the first Marina sampling day that was beginning to experience the pollution event, the concentration of dibenzofuran was close to both the pollution day of June 14 and the downtown Goodyear location. The Goodyear location was exposed to a higher density of automotive traffic, as was the Dicon site on June 14. Therefore, it is concluded that the dibenzofuran is more strongly associated with automotive traffic alone, which leads to the tentative conclusion that the elevated concentration at the Marina on June 13 may be due to automotive sources.

The carcinogenic PAH compounds are present in concentrations ranging up to tens of nanograms per cubic meter. A full risk assessment would have to be conducted to draw accurate conclusions about these concentrations.

Figure 12. Graphic Representation of SVOC Summation

Hydrogen Sulfide

Hydrogen sulfide was monitored using a Jerome 631-X gold foil sensor. The concentrations detected were low across the board and only once were close to an odor threshold.

Table 13. Hydrogen Sulfide Data (ppbv)

Figure 13. Hydrogen Sulfide Concentrations (ppbv)

Meteorological Data

As noted above, the on-site meteorological data collection failed due to data transfer problems, so the Oakland airport data was used instead. This data set is in the appendix, including plots of the wind direction distribution. This airport is close enough to the sampling areas that it should be representative of major trends. Micrometeorological conditions would not be reflected in this data set, and therefore cannot be used to correlate any small effect in the real-time data sets.

Two factors stand out about the meteorological data. First, the days of June 13 and 14 showed distinct atypical behavior with the wind coming out of the north as low wind speeds. These conditions caused the buildup of high pollutant concentrations noted in the various data sets. The other factor is the consistent normal pattern of wind coming directly across the bay, with little deviation.

It is this wind condition that moderates the pollutant exposure to West Berkeley. The concentrations of PEC and other pollutants directly associated with highway traffic was lower than expected due to its proximity to the busy 1-80 corridor. However, this expected effect was decreased by the strong input of clean air masses from the bay that causes a definite dilution of the pollutants as one travels east. This strong effect is notable in the remainder of the data set, which shows a number of pollutants, but at levels lower than might be expected due to the many sources of emissions in the area, both vehicular and industrial. Therefore, although the impact of these sources would be expected to be great in this area, the effect is mitigated somewhat by the constant input of clean air into the area.

Summary

Table 14 contains a summary of the entire data set, with the maximum, averages, and 95% upper confidence limit (UCL). The UCL is used in any risk assessment calculation.

Conclusions and Recommendations

Although the data set was limited and questions still remain, several conclusions can be drawn from this data set. Referring back to the objectives of the program as listed in the introduction:

What pollutants are the residents of West Berkeley exposed to?

The West Berkeley area appears to be impacted from the effects of the 1-80 corridor, although these effects are mitigated by the strong input of clean air from the bay into the area. However, the vehicular and industrial sources contribute a large number of potentially high risk pollutants to the atmosphere in this area. Volatile organic compounds, semivolatile organic compounds, aldehydes and ketones, and diesel exhaust appear to have the highest potential for adverse risk exposure based on this limited data set.

Are any of these pollutants of particular concern?

A number of pollutants were noted to have been detected at levels of potential concern: Acrolein, acetaldehyde, BTEX, 1,4-dioxane, methylene chloride, 1,2,4-trimethyl benzene, chloromethane, methylene chloride, diesel exhaust, PAH compounds. In addition, the semivolatile organic compound mix appears to be of concern, although the limited scope of this project will not allow a detailed examination.

What is the impact of the 1-80 corridor?

The 1-80 corridor is a major source of pollution to the area. However, as mentioned above, the effect of the clean bay wind lessens the impact to the community from this constant source. Compared to literature values of diesel exhaust in urban areas adjacent to such a high traffic source, the concentrations of diesel exhaust should probably be higher by a factor of 1.5-2.

What is the impact of the industrial sources in the area?

The local industrial sources do appear to contribute to the pollutant mix, although given the limitations of this study, no specific correlation could be made with any particular source.

Determine if possible, what compounds were causing odor complaints in the West Berkeley area.

No specific compound was identified as causing the odors detected in the area. Most detected compounds were present below their nominal odor threshold. However, additive effects that are difficult to discern could have magnified the effect of any of these chemicals.

• Is the West Berkeley area significantly different from other areas of Berkeley?

For many of the pollutants, the proximity to the sources is critical in the potential exposure evaluation since these sources are localized. However, for particular matter, especially PM10, the concentrations appear to be regional, with little difference between various sites throughout the city. The eastern area of Berkeley benefits from both the effects of altitude and distance from the majority of the sources. The constant input of clean air into the area from the bay wind assists in diluting the emissions from the city and results in fewer detectable compounds at lower concentrations at areas to the east of West Berkeley.

What should be done for further monitoring?

It is recommended that two actions be taken. First, an examination of the data set by a qualified risk assessment expert to provide a more thorough evaluation of the potential for health risk from the detected compounds. Second, a more focussed and longer term study of the area should be conducted in order to elucidate unresolved questions such as the specific fingerprint of individual industries and the impact of I-80. Although this data set shows some trends, a longer term study of the 1-80 impact should be conducted before making a complete conclusion. This monitoring should include continuous diesel monitoring and a less frequent VOC, aldehyde, and SVOC sampling. During this longer term study, a limited subset of the entire program as conducted here, including metals, etc. should be conducted for confirmation of this data set under the prevailing conditions.

Return to: West Berkeley Air Monitoring Part 1