The magnitude of the fires and the extensive publicity about the amount of smoke sparked concern around the world regarding effects on global processes such as ozone depletion, acid rain, global warming, and other atmospheric phenomena. For example, some worried that the smoke could disrupt the monsoon season in southern Asia and trigger a drought affecting crops in India and Pakistan (Horgan, 1991a).
Although no global effects were noted, the passage of the smoke was detected worldwide where very sensitive equipment was located. Beginning in February 1991, the National Oceanic and Atmospheric Administration (NOAA) recorded numerous "soot spikes" in air-sampling data at its observatory located 4000m above sea level in Hawaii. Wind-pattern records indicate that the sooty air had left the Persian Gulf 7-10 days earlier. The March levels at Mauna Loa were five times higher than during March in the previous three years; these levels were still low enough to pose negligible health risks. No global disaster occurred, as some predicted immediately after the fires began (Horgan, 1991a, 1991b).
Firefighters started to cap the flaming oil wells in April, expecting that they would need up to two years to extinguish all fires. In the meantime, a coordinated international research effort began in the spring of 1991 to assess the impact of the fires on health and the environment.
|Ozone (O3)||8 hour||0.080 ppm||(160 µg/m3)|
|PM10||Annual mean||50 µg/m3|
|24 hour||150 µg/m3|
|PM2.5||Annual mean||15 µg/m3|
|24 hour||65 µg/m3|
|Carbon Monoxide (CO)||8 hour||9 ppm||(10 µg/m3)|
|1 hour||35 ppm||(40 µg/m3)|
|Nitrogen Dioxide (NO2)||Annual mean||0.053 ppm||(100 µg/m3)|
|Lead (Pb)||Calendar quarter||1.5 µg/m3|
|Sulfur Dioxide (SO2)||Annual mean||0.030 ppm||(80 µg/m3)|
|24 hour||0.14 ppm||(365 µg/m3)|
|Benzene||Acute||0.5 ppm (1600µg/m3)||Immunological|
|Toluene||Acute||3 ppm (11,500 µg/m3)||Neurological|
|Chronic||1 ppm (3800 µg/m3)||Neurological|
|Xylene||Acute||1 ppm (4400 µg/m3)||Neurological|
|Intermediate||0.7 ppm (3100 µg/m3)||Developmental|
|Chronic||0.1 ppm (440 µg/m3)||Neurological|
|Chromium (III)||Intermediate||0.02 µg/m3||Respiratory|
SOURCE: ATSDR, 1997.The National Institute for Occupational Safety and Health (NIOSH) was established by the Occupational Safety and Health Act of 1970 as part of the Centers for Disease Control (CDC). One of NIOSH's mandates is to recommend criteria for preventing disease and hazardous conditions in the workplace. NIOSH develops and periodically revises recommended exposure limits--i.e., time-weighted average concentrations (TWAs)--for hazardous substances by evaluating all available medical, biological, and other relevant information. These recommendations are transmitted to the Occupational Safety and Health Administration (OSHA) and the Mine Safety and Health Administration for use in promulgating legal standards. NIOSH's TWA standards are the maximum recommended exposures in the workplace for up to a 10-hour workday during a 40-hour workweek. OSHA's TWA concentrations must not be exceeded during any 8-hour workshift of a 40-hour workweek.
The American Conference of Governmental Industrial Hygienists (ACGIH), a professional society--not a government agency--devoted to the administrative and technical aspects of occupational and environmental health, develops Threshold Limit Values (TLVs) as recommendations or guidelines for use in the practice of industrial hygiene in the workplace. TLVs are TWA concentrations that should not be exceeded during any 8-hour workshift of a 40-hour workweek. All these concentration limits are set at levels believed to be without adverse effects for nearly all workers during repeated daily exposure. Table 2.3 lists NIOSH, OSHA, and ACGIH recommended occupational limits for the noted pollutants.
NIOSH, OSHA, and ACGIH Occupational Limits
for the Pollutants of Interest
SOURCES: NIOSH, 1997; ACGIH, 1997.Since the EPA's standards are set to protect the general population--including those most vulnerable, such as small children, the elderly, and people with respiratory and other diseases--from increased health risks due to exposures to ambient pollutants, they are much lower than occupational standards (e.g., ACGIH, NIOSH, and OSHA), and they include a margin of safety.
NOTE: NA = Not applicable.
aComponents of coal tar pitch volatiles.
bConcentration limits are for their respective TWAs except for NO 2.
cShort-term exposure limit, a 15-minute TWA.
dPM10 not otherwise regulated.
As discussed above, in the United States there are different standards of acceptable levels of contaminants set according to which population needs to be protected. The EPA's NAAQS, for the ubiquitous criteria pollutants, are targeted for the general population for continuous ambient exposures. ATSDR-MRLs give the concentrations of hazardous substances that will likely not affect the general population through daily exposure. NIOSH, OSHA, and ACGIH standards are for occupational exposures during 40-hour workweeks lasting the worker's lifetime.
The armed forces deployed to the Gulf theater are a unique segment of the population. They are predominately young (18-40), fit, and healthy. They stayed in the region after the onset of the Kuwait oil fires for (at most) 6-8 months. There are no studies in the scientific literature that focus on the possible health effects due to exposures to contaminants in this population segment. What standards should be considered appropriate for this group, exposed for 24 hours over a limited period of time? The NAAQS and MRL ambient levels are unrealistic because of the margins of safety included to protect the most vulnerable members of the population. The NIOSH, OSHA, and ACGIH occupational standards, although seemingly more appropriate, assume a step-function exposure with periods of low levels in-between but lasting for many years. Perhaps the occupational standards combined with an empirical factor to account for the continuous exposure would give a reasonable exposure-limit estimate.
|Riyadh Concentration||EPA--NAAQS Ambient Standard||ACGIH-Occupational Standard|
|Maximum average hourly||2.7||0.16|
|Maximum average daily||2.0||0.05|
|Overall sampling average||0.86||0.040||NA||0.053||25||3.0|
SOURCE: Rowe, 1991.Concentrations of NO2 were measured throughout the state of Bahrain from January 6 to January 29, 1991, at the onset of the Persian Gulf War and before the burning of the oil wells. A large number (approximately 100,000) of jet flights took place during that period. The highest NO2 levels were concentrated in Manama, the capital, with weekly mean values up to 0.145 ppm (273 µg/m3), while the lowest were in coastal villages, which had means around 0.028 ppm (53 µg/m3). Industrial areas had lower levels than the urban areas, which is characteristic where high traffic densities are the main source of NO2 (Danish and Madany, 1992).
NOTE: NA = not applicable.
Even though only limited environmental data are available, high particulate levels have been documented throughout the Persian Gulf region: 5080 µg/m3 in Riyadh, Saudi Arabia in 1982; 630 µg/m3 in Kuwait in 1983; and 674 µg/m3 in Bahrain in 1987 (Madany and Raveendran, 1992). A study from Dhahran, Saudi Arabia, reports TSP measurements for 100 days from November 1980 to March 1981. The average maximum daily value for the period was 737 µg/m3, and the geometric mean for the period was 339 µg/m3. But when the Shammal winds were blowing, peak daily concentrations reached the extraordinary values of 2923 µg/m3 (Khattak, 1982). These values are about 20 times the 24-hour U.S. ambient standard for PM10 of 150 µg/m3. The daily variability in PM10 concentration is illustrated in Figure 4.2 for Doha, Kuwait, from June to December 1991.
|Plume Type & Date Sampled (1991)||CO2||TOCa||CO||Soot (Elemental carbon)||CH4||SO2||NOx||Particles < 3.5 µm Diameter||Saltsc|
|Super-composite plume (160 km downwind from Kuwait City) May 28||10,313
|Composite plume from Greater Burgan field (20 km downwind of fires) June 12||29,143 (95.1)||915
|Individual black plume (in Umm Qudair field) June 9||8,107
|Individual white plume (in north field) June 8||35,893
|From a pool fire (in Minagish field) June 2||15,536
SOURCE: Ferek, 1992.
aTOC = Total nonmethane organic carbon in the vapor phase.
bPercentage of carbon specie contributing to the total carbon in the plume is included in the parentheses. It indicates combustion efficiency; a higher percentage means more efficient combustion.
cSalts = Sum of all salts measured.
The ground-level sampling in Kuwait City was taken during an abrupt change in weather conditions on August 7. Until August 5, winds with speeds of 35-55 km/hr (10-15 m/sec) transported the smoke from the oil fields toward the Persian Gulf, with little visual evidence of a plume across Kuwait City. On August 5, a strong, low-lying inversion developed, winds calmed, and visibility declined sharply. Winds then returned from the northwest, and, by August 9, dispersed the material that had accumulated over the city.
In the August 7 sample, the dominant component was sand dust. Sulfur, as SO2, increased by about 50 percent during the inversion. Concentrations of Cl, Pb, Br, and Zn increased at least ten-fold. The ratio of Pb to Br of about three remained constant throughout the sampling, suggesting that their primary source was local automotive traffic and not the oil well fires. Concentrations of Ca, K, Ti, Fe, and Mn increased by less than 50 percent during the inversion period. The ratios of Si, Fe, K, Ti, and Mn to Al were within 30 percent of the values for local desert soils and similar to soils in Arizona. PAH levels in Kuwait City were typically less than 0.001 µg/m3 as shown in Table 2.11 (Stevens et al., 1993).
The daily PM10 concentrations ranged from 139 to 673 µg/m3 but, although quite high, cannot be attributed only to the oil fires. Comparison with available data on particulate matter from before the Gulf War shows that these levels are common for the region.
The mean daily concentrations of Ni and V ranged from 7 to 42 ng/m3 and 11 to 42 ng/m3, respectively. They were strongly correlated, indicating that they had a common source: the oil fires (Madany, 1992).
Table 2.6 depicts the average concentrations of individual components of the PAHs in Bahrain for the study period as well as what is considered background, rural, and urban values for cities around the world for comparison (Madany, 1992). It is important to note that the PAH levels in Bahrain, which is downwind from Kuwait, were at least an order of magnitude lower than the European cities with high PAH concentrations.
|Compound||Alaska||Lake Superior||Netherlands||Greece||Berlin||San Francisco||Bahrain|
SOURCE: Madany, 1992.A study on a "positive" aspect of the Kuwait oil fires looked into the comfort of the residents of Jubail, Saudi Arabia, during the Kuwait oil fires. Many Jubail residents said that it had been noticeably cooler since the fires were ignited in Kuwait. Some residents speculated that temperatures were 10o to 20oC below normal. Comparison of the mean air temperatures for the months of May and June 1991 with historical data for the same months indicates that the actual decrease in temperatures was not statistically significant. On the other hand, the mean temperatures for January to April were slightly higher than those predicted from historical data. Solar radiation data indicate a 26-36 percent decrease compared to the same months during 1979-1990. According to one researcher (Riley, 1992), "One way of looking at these results is to think of the smoke plumes as being analogous to the shade of an extended palm grove. The air temperature in the shade is the same as in full sunlight, but the level of human comfort is significantly higher under the trees because the solar-radiation load on an individual is reduced." This is an example of how the general population's perception of an effect can lead to a wrong conclusion.
NOTE: NA = not available.
Permanent ambient air monitoring stations were established at four locations in Saudi Arabia and six in Kuwait, although two in Kuwait had to be abandoned quickly due to logistical difficulties (see Figures 2.1 and 2.2). The sites selected were locations where large concentrations of U.S. troops and DoD civilians were stationed for long periods of time. The two mostly civilian sites were the U.S. Embassy in Kuwait and the Al Ahmadi Hospital; the others were mostly military sites.
Figure 2.1--Monitoring Sites in Kuwait
Figure 2.2--Monitoring Sites in Saudi Arabia
Based on the hazardous substances to be monitored--crude oil, by-products of incomplete combustion, breakdown products--scientists from USAEHA de-cided on a list of pollutants of concern that needed to be monitored in the Gulf region affected by the oil well fires (Table 2.7).
|Volatile Organic Compounds (VOC)|
|Polycyclic Aromatic Hydrocarbons (PAH)|
|Acenaphthene||Benzo (g,h,i) perylene||Ideno(1,2,3 -cd)pyrene|
|Hydrochloric acid||Nitric acid||Sulfuric acid|
|Criteria Pollutant Gases|
|Nitrogen dioxide||Nitric oxide||Ozone|
|Particulates and Metals|
SOURCE: USAEHA, 1994.Soil Sampling. Soil sampling was also performed at the air sites. There were no consistent increases in soil metals concentrations above background, except for lead. Lead increased at all sites, as it did in the air data, probably reflecting an increase in vehicular traffic and subsequent lead emissions from local gasoline. There were no VOC or PAH levels above the instrumental detection limit. There also was no detection of Cr(VI) in 76 samples analyzed with a detection limit of 100 ppb (USAEHA, 1994).
Air Sampling. The USAEHA sampling campaign measured little change in the general air quality during the monitoring period. Table 2.8 lists the highest mean values of the contaminants listed in Table 2.7 as measured by the USAEHA during their 1991 campaign. Although considerable increases were noted in particulate matter, these concentrations were considered to be within the range common to this area.
|Pollutant||Location||Mean [c]a||ACGIH's TLVs|
|Ozone||O3||Riyadh||53.4 µg/m3||100c µg/m3|
|Sulfur dioxide||SO2||Riyadh||23.8 µg/m3||5200 µg/m3|
|Nitrogen dioxide||NO2||Khobar||58.5 µg/m3||5600 µg/m3|
|Nitric oxide||NO||Khobar||24.2 µg/m3||31,000 µg/m3|
|Acenaphtheneb||Eskan Village||0.62 ng/m3||200,000 ng/m3|
|Benzo(a)anthraceneb||Eskan Village||0.60 ng/m3||200,000 ng/m3|
|Biphenylb||Eskan Village||7.20 ng/m3||200,000 ng/m3|
|Chryseneb||Eskan Village||0.48 ng/m3||200,000 ng/m3|
|Fluorantheneb||Eskan Village||1.41 ng/m3||200,000 ng/m3|
|Phenanthreneb||Ahmadi||0.48 ng/m3||200,000 ng/m3|
|Pyreneb||Eskan Village||0.65 ng/m3||200,000 ng/m3|
|Particulate||PM10||Ahmadi||354 µg/m3||3000d µg/m3|
|Cadmium||Cd||Camp 1||0.003 µg/m3||10 µg/m3|
|Chromium III||Cr||Camp 1||0.027 µg/m3||500 µg/m3|
|Nickel||Ni||U.S. Embassy||0.052 µg/m3||120 µg/m3|
|Lead||Pb||Eskan Village||0.675 µg/m3||50 µg/m3|
|Vanadium||V||Ahmadi||0.028 µg/m3||50 µg/m3|
|Zinc||Zn||Camp 1||0.068 µg/m3||500 µg/m3|
|Benzene||Ahmadi||7.82 µg/m3||1600 µg/m3|
|Toluene||Ahmadi||21.8 µg/m3||188,000 µg/m3|
|Ethyl benzene||Ahmadi||14.7 µg/m3||435,000 µg/m3|
|m,p-Xylene||Ahmadi||40.5 µg/m3||435,000 µg/m3|
|0-Xylene||Ahmadi||12.8 µg/m3||435,000 µg/m3|
NOTES: NA: Standard or recommended concentration not available.Exposures to several VOCs (i.e., benzene, toluene, ethyl-benzene, and xylene) were similar to levels observed in cities with major petrochemical industries (i.e., Houston and Philadelphia (USAEHA, 1994)). Figure 2.3 compares median VOC concentrations in Kuwait, Saudi Arabia, and several U.S. cities. The median VOC concentrations for benzene, toluene, ethyl-benzene, and the xylenes at the Kuwait and Saudi Arabian sites are comparable to concentrations in urban centers in the U.S. The levels of NO2, CO, SO2, H2S, and PAHs were lower than expected, given the magnitude of the fires, and did not exceed those seen in U.S. cities or the EPA standards where established.
bThere were only a few samples above the detection limit.
cTLV performing heavy work.
dPM10 not otherwise regulated.
NOTE: Toluene measurement for Los Angeles not available.
High levels of airborne particulate matter (sand and soot) were observed at several monitoring sites. Analysis of the samples indicated that the particles were mostly sand-based materials; high levels of airborne sand particulates are typical for this region of the world (Kirkpatrick, 1997). Within the PM10 samples of particulate matter, levels of PAHs and toxic metals were low.
A small subset of the ambient air samples collected in Kuwait and Saudi Arabia were analyzed to determine particle-type class and particle-size distribution of the PM10 data. The assigned classes fell into the following main categories: earth crustal (silica-rich, e.g., quartz), calcium bearing (calcium-rich, e.g., dolomite, gypsum), salt particles, carbon rich (e.g., soot), and miscellaneous (USAEHA, 1992). Figure 2.4 shows the percentile composition of the particulate matter in the air of Kuwait and Saudi Arabia (USAEHA, 1992). Considering that the sand of the Arabian Peninsula is rich in calcium and silica, it indicates that most of the PM10 is of sand origin and that in Kuwait about 23 percent of the total PM10 mass was contributed by soot from the oil well fires.
SOURCES: Kirkpatrick, 1997; USAEHA, 1992.
SOURCES: Kirkpatrick, 1997; USAEHA, 1992.
The results are summarized in Table 2.9. The table provides means and standard deviations, maximums measured, and ACGIH's TLVs. Most measured pollutant concentrations were well below the occupational TLVs.
Summary of Industrial Hygiene Air Sampling in Kuwait and Saudi
|Pollutant||Kuwaita||Saudi Arabiaa||Maximum Value||ACGIH's TLVs|
|PM10||0.35 (0.64)||0.46 (0.24)||2.00||3.0|
|Coal Tar Pitch||0.06 (0.96)||0.10 (0.09)||0.21||0.2|
|Nitrogen Dioxide||1.65 (1.30)||0.40 (0.24)||6.70||5.6|
|Sulfur Dioxide||0.47 (0.72)||0.53 (0.65)||1.90||5.2|
|Nitric Acid||0.05 (0.02)||0.04 (0.05)||0.12||5.2|
|Sulfuric Acid||0.04 (0.01)||0.03 (0.01)||0.05||1.0|
SOURCE USAEHA, 1994; ACGIH, 1997.
NOTES: amean (standard deviation). BDL: Below Detection Limit.
|Khobar Towers||Camp Thunderock|
SOURCES: 1991 data: USAEHA, 1994; 1993 data: Kirkpatrick, 1997.
NOTE: NA = Not available.
The results indicate that the metals and VOC readings at Khobar Towers in 1993 were about the same as those in 1991, but PAH and PM10 levels were lower. The November 1991 VOC data for Khobar Towers are similar to the November 1993 levels, except for toluene. The Khobar Towers VOC levels are a factor of three higher than Camp Thunderock. The PAH levels detected in November 1993 were 2 to 8 times lower than in November 1991. For PM10 the November 1993 mean levels are lower than in November 1991, decreasing from a mean concentration of 62 µg/m3 to 52 µg/m3.
At Camp Thunderock, the readings for all four categories were substantially lower in 1993 than they were in 1991. The metal levels from November 1993 are a factor of 2 lower than those in November 1991. In the November 1993 PAH data, most of the compounds are below detection limit and the rest are about three times lower than those in November 1991. PM10 levels decrease from 84 µg/m3 to 44 µg/m3.
Table 2.11 displays the maximum or 95th-percentile concentrations in the air for the pollutants of concern as measured by the USAEHA from May to December 1991, and the ACGIH-recommended exposure limits for hazardous substances in the workplace. These results show that, except for ozone, the maximum concentrations for all pollutants in the Gulf were several orders of magnitude lower than ACGIH occupational standards. And ozone, which is ubiquitous in the U.S., was still lower than in many U.S. urban areas where summer episodes reach twice the NAAQS.
A possible objection to the above comparison is that U.S. personnel in the Gulf were being exposed to air pollution 168 hours per week for up to 70 weeks, while occupational exposures are spread over 40 hours per week during an adult working lifetime. Nevertheless, if the mean pollutant concentrations due to the Kuwait oil well fires are compared to the NAAQS and to the ATSDR's MRL levels, the Gulf levels were lower than the U.S. standards set for the general population (except for PM10), and lower than the daily exposures of millions living in major U.S. cities. However, PM10 levels, unrelated to the oil well fires, were much higher than ambient levels in the U.S., but within the ACGIH's TLV levels. Gulf War veterans, like people living in urban areas in the U.S., were exposed to multiple pollutants simultaneously for which there are no standards.
|Pollutant||Sym||Location||ACGIH TLVs||Maximum [C]a||Maximum [C]b|
|Ozone||O3||Camp Thunderock||100 µg/m3||104.8 µg/m3||(Kuwait City only)|
|Sulfur dioxide||SO2||Ahmadi||5200 µg/m3||92.5 µg/m3||11.0 µg/m3|
|Nitrogen dioxide||NO2||Khobar||5600 µg/m3||86.1 µg/m3|
|Nitric oxide||NO||Khobar||31,000 µg/m3||61.1 µg/m3|
|Acenaphthenec||Eskan Village||200,000 ng/m3||2.25 ng/m3||> 1 ng/m3|
|Benzo(a)anthracenec||Eskan Village||200,000 ng/m3||2.23 ng/m3||> 1 ng/m3|
|Biphenylc||Eskan Village||200,000 ng/m3||19.07 ng/m3||> 1 ng/m3|
|Chrysenec||Eskan Village||200,000 ng/m3||2.25 ng/m3||> 1 ng/m3|
|Fluoranthenec||KKMC||200,000 ng/m3||2.23 ng/m3||> 1 ng/m3|
|Phenanthrenec||Ahmadi||200,000 ng/m3||1.84 ng/m3||> 1 ng/m3|
|Pyrenec||Eskan Village||200,000 ng/m3||3.54 ng/m3||> 1 ng/m3|
|Particulate||PM10||U.S. Embassy||3000 µg/m3||1842 µg/m3|
|Cadmium||Cd||Camp 1||10 µg/m3||0.0078 µg/m3|
|Chromium||Cr||U.S. Embassy||500 µg/m3||0.0898 µg/m3||0.013 µg/m3|
|Lead||Pb||Eskan Village||50 µg/m3||1.596 µg/m3||1.671 µg/m3|
|Nickel||Ni||Camp 1||120 µg/m3||0.2136 µg/m3||0.0081 µg/m3|
|Vanadium||V||Camp 1||50 µg/m3||0.0898 µg/m3||0.0093 µg/m3|
|Zinc||Zn||Camp 1||500 µg/m3||0.193 µg/m3||0.172 µg/m3|
|Pollutant||Sym||Location||ACGIH TLVs||Maximum [C]a||Maximum [C]b|
|Benzene||Ahmadi||1600 µg/m3||13.1 µg/m3|
|Toluene||Ahmadi||188,000 µg/m3||36.9 µg/m3|
|Ethyl benzene||Ahmadi||435,000 µg/m3||41.2 µg/m3|
|m,p-Xylene||Ahmadi||435,000 µg/m3||116 µg/m3|
|o-Xylene||Ahmadi||435,000 µg/m3||30.4 µg/m3|
aFor particulates, metals, and VOCs, this column gives the 95th percentile [C]; for PAHs and Criteria Pollutants it gives the maximum [C] (USAEHA, 1994).
bStevens et al., 1993.
cThere were only a few samples above the detection limit. The ACGIH TLV is for coal tar pitch volatiles.
The cut-off value of 3.5 mm, PM3.5, was arbitrarily set in the particle analyzer. These measurements were taken before the PM2.5 standard was promulgated and is the closest available data above PM2.5.