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N K021'70094 EXPOSURE TO POLLUTANTS 11 with outdoor CO pollution. In individual rooms, increases of I to 2 ppm were found. At a conference of the Academy of Allergy, cigarette-produced CO pollution was measured in the room and in the alveolar air of 1 I persons attending (Slavin and Hertz, 1975). During the course of the meeting a ban on smoking was passed (unexpectedly). Two sets of conditions were thus examined, free smoking and non smoking. Initial concentrations in the meeting room during both days were I to 2 ppm. In the larger conference room, 8 ppm was registered by mid morning, and in the smaller room, 10 ppm was reached during the free smoking periods. After the smoking ban was enacted, CO concentrations remained about I to 2 ppm. Alveo- lar air CO content average 7 ppm in eight nonsmokers during free smoking and between 2 to 3 ppm in all individuals during nonsmoking. In a study by Godin et a/. (1972) higher values of CO were reported in a theater foyer, where smoking was permitted, than in the auditorium, where smoking was not permitted. Differences were small (3.4 ± 0.08 ppm vs 1.4 ± 0.8 ppm, respec- tively). Further tests of tobacco smoke were conducted by Russell and Feyerabend (1975). They report on an experiment in which 80 cigarettes and two cigars were burned or smoked in an unventilated room, resulting in 38 ppm of CO. Individuals exposed in the experiment were then compared with two additional groups, 14 members of Russell's research group and 31 staff members of a nearby hospital. Blood and urinary nicotine levels were measured. For exposed nonsmokers, plasma nicotine increased from 0.73 to 0.90 ng/ml. Urinary nicotine after smoking was 80 ng/ml. Two other groups of non smokers (not exposed to the smoky room air) had 12.4 and 8.9 ng/ml of urinary nicotine. However, it is unclear what the exposure to tobacco smoke was for the comparison individuals. Horning et al. (1973) studied lab room air for nicotine content. They also investigated, as did Russell, physiological conditions of smokers' and nonsmokers' urine. Nicotine was detected in the air, but not in the water of the lab. (No precise levels were reported.) Nicotine was found in nonsmokers to be 5% of the level found in smokers. (But actual levels were not given.) A few additional values for nicotine in public places were reported on by Hinds and First (1975). Samples were obtained for a restaurant, a cocktail lounge, and a student lounge with a hand-carried pump and filter. (However, this method tends to underestimate nicotine values [Harke, I974d].) The restaurant was found to contain 5.2µg/m3 nicotine, while the cocktail lounge had 10.3µg/m3. The student lounge held 2.8 f.cg/m3 of nicotine. These results were based on only a few samples taken and conditions were not detailed in each case (e.g., number of persons, room dimensions, number of smokers, etc.) On the basis of average amounts of nicotine/cigarette, cigarette equivalencies/hour were calculated to be 0.004 for the restaurant, and 0.009 and 0.002 for the cocktail and the student lounges, respec- tively. These latter results are more speculative than quantitative, however. Smoking during 19 public gatherings in three arenas was the subject of an investigation by Elliott and Rowe (1975). The three arenas differed in size, ventila- tion, and smoking restrictions. Average CO was 14.3 ppm, particulates 367 MIRSTER-Sipp 003,853

12 STERLING AND KOBAYASHI H K®2170005 µg/m3, and BaP 12.5 ng/m3 compared to background levels of 3 ppm, 68 µg/m3, and 0.69 ng/m3. Data insufficiencies prohibit reliable cross comparisons of the three arenas. However, differences in pollutant levels within one arena correlate well with crowd size. Smoking and poor ventilation are reported as contributing causes of these pollutant levels; however, no measures were taken. Galuskinova (1964) reports on indoor benzo(a)pyrene air pollution in a Prague restaurant. Values found in the restaurant were compared with those for the city as a whole in both winter and summer. These values differed little in the summer but differed significantly in the winter (0.28 to 4.6/100 m3 in the city and 2.83 to 14.4/100 m3 in the restaurant). Galuskinova attributes the increase indoors to smoking. From what is known about entrapment and generation of pollutants, especially from cooking in a restaurant, such an inference would not be reasonable. POLLUTANTS IN TRANSPORTATlON-RELATED ENCLOSURES Automobiles, buses, garages, tunnels, subways, underground streets, and plat- forms provide some form of enclosure (similar to that of households and office buildings) which may allow toxic substances to build up. The enclosure may be relatively well sealed, as in the cases of some automobiles, thus increasing the concentrating potential. Automobiles In a study by Brice and Roesler (1966), CO and hydrocarbons were measured in six major cities. Samples were taken so as to simulate the exposure to the driver. In warm weather, samples were taken with windows open, and in the winter with windows closed and heater/blowers on. In-car concentrations were shown to be consistently and considerably greater than (CAMP) values found in the cities Continuous Air Monitoring Programs. Average CO values in automobiles were 31.3 ppm, while outside values averaged 14.2 ppm. Average in-car hydrocarbons measured 6.4 ppm, while in-city values measured 3.5 ppm. CO, monitored in cars in Paris (Chovin, 1967), showed mean concentrations of 24.3 ppm and 24.6 ppm in 1965 and 1966 studies. COHb levels of 1670 drivers involved in accidents were higher than those obtained from 3818 workers exposed to CO and 1530 individual cases of CO poisoning. Haagen-Smit (1966) continuously recorded CO by means of a glass tube inserted in the windshield of a car driven through downtown Los Angeles. The mean CO level was 37 ppm in normal traffic and 54 ppm in heavy traffic. However, there were peaks as high as 220 ppm. A number of CO samples within moving cars were obtained by Godin et al. (1972). Samples were taken both with heater fan on and off. Windows were closed at all times. CO remained at parking levels until the blower was activated. Street- level CO was reached in 30 to 60 seconds. Fluctuations during driving occurred with street-level changes, congested and "walled-in" areas having the highest levels of CO. Peak mean concentrations for heavy traffic were 78.8 ± 58.0 ppm. CO may also leak into the car from emissions of its own engine. Amiro (1969) reported that of 19 automobiles tested in 1967, 9 were found to have CO emissions of up to 400 ppm leaking into the car. In a test for CO on a random sample of 60 cars, 30 were found to leak emission products (measured by CO) in varying SHP 0030654

H KE21'70096 EXPOSURE TO POLLUTANTS 13 amounts. Internal emission is a considerable hazard since many automobiles are very nearly air tight with their windows and vents closed. Oxygen depletion is a problem often found in sealed environments and may be adding to the effects of other pollutants. At the same time, when a car is well sealed, emissions from the engine may remain entrapped within the automobile. Buses Fifty-two percent of 190 empty buses, tested for CO while the motor was running, were found to contain 25 to 800 ppm inside the bus. The highest concen- tration usually occurred at the rear of the bus, or at the front near the gear box (Amiro, 1969). Johnson et al. (1975b) also tested CO in the passenger compartments of school buses. Ninety-seven tests were made. The mean range with the motor running was 10 to 25 ppm, although 8 buses were found to contain levels from 35 to 100 ppm of CO. Subways Contaminants inside subways have been tested. One study, conducted by Godin et al. (1972), has reported on CO values obtained during subway travel. Allowing for high (0.08 to 0.18%) CO2 levels, CO concentrations were found to reach 3.4 ± 2.6 ppm on open sections of track. In tunnels, however, CO averaged as high as 5.5 ± 3.2 ppm. As smoking is not permitted on subways,jhese levels were thought to be due to street-level air intakes. Another study conducted in Osaka by Matsumoto and Kitamura (1971) found that on the average, levels of dust on platforms exceeded above-ground concentrations by one and a half times. Values for dust inside trains of subways ranged from 0.43 to 2.42 mg/m3 with a mean concentration of 1.20 mg/m3. Tunnels Tunnels are basically closed systems because of their structural design (and two-way traffic flow.) As closed systems, they trap pollutants inside. Conlee et al. (1967) compared values taken from the Sumner Tunnel in Boston when it was used as a one-way tube and when it was used as a two-way system. Pollutant levels decreased when the tunnel was used for one-way traffic only. Larsen and Konopinski (1962) conducted a thorough study of pollutants in the Sumner Tunnel. CO peaked at 250 ppm (at this concentration warning signals caused new vents to be opened,) Many weekday peaks ranged from 120 to 150 ppm. The soiling index inside the tunnel was found to be five times that outside. Particulate matter was 100 µg/m3 outside and 600 µg/m3 inside. Organic particu- late matter was found to be 11 times the outside amount, which indicates consid- erable enrichment inside the tunnel. Lead inside the tunnel was found to be 45 times the outside levels. Benzo(a)pyrene was as much as 200 times more concen- trated inside the tunnel than outside. Findings similar to Konopinski's were re- ported by Chovin (1967) in a Paris auto-exhaust study. Chovin also found that the concentration of pollutants within a tunnel depended on its length. Ayres et al. (1973), reporting for New York tunnels, found that CO averages were 63 ppm for the 30-day testing period with peaks of 217 ppm. Lead averaged 30.9 µg/m' with peaks up to 98 µg/m', as determined by high-volume sampling. Hydrocarbons 0 MRS TER-SPP '0031839E'

14 STERLING AND KOBAYASHI •' •• 12-- 7U Q97 average 7.9 ppm with peaks at 29.6 ppm. Similar findings were reported by W il- kins (1956) of CO levels in Blackwell Tunnel in London. Levels ranged from 150 to 590 ppm, in 1954, and from 235 to 470 ppm in 1955. A later investigation of the same tunnel, and of Rotherhithe Tunnel, was conducted by Wailer et a1. (1961). Again, values for all pollutants were extremely high. Particulates ranged from 93 to 235 µg/100 m'. CO on the average was over 100 ppm, with a maximum peak at 500 ppm. Oxides of nitrogen ranged from 1 to 8 ppm. Garages Parking garages may have pollutant-concentrating abilities similar to those of tunnels. Ramsey (1967) found garage air to contain from 7 ppm to 240 ppm of CO. The mean concentration was 58.9 ppm. In all employees, COHb levels were found to increase significantly from 2.4% in the morning to 8.4% in the evening. Trom- peo et al. (1964) reported similar findings for garages in Turin. CO levels were found to reach 100 ppm, on the average, ranging from 10 to 300 ppm. Chovin (1967) measured 80 to 100 ppm of CO on the average, with frequent peaks of 200 ppm lasting for as long as 20 minutes, in ventilated Paris garages. Goldsmith (1970) reported that traffic jams in parking garages during mass exits could raise levels of pollutants to extreme concentrations. While no measurements have been taken of pollutants such as benzo(a)pyrene, soiling particulates, or lead, the findings on CO would indicate that these pollutant levels are also probably very high. Airplanes Unlike submarines, fresh air enters the aircraft during ftight, and little if any machinery within the passenger cabin contributes to the pollution load. A study by the U.S. Department of Transportation (1971) tested the air during a large number of flights for CO, hydrocarbons, ammonia, particulates, ozone, relative humidity, and temperature. Sampling was undertaken in four locations throughout each aircraft. Pollutant concentrations were, on the whole, low. CO for the majority of flights was less than 5 ppm and averaged 2 ppm. No hydrocarbon contamination was detected. Particulates were higher, measuring 120 Ag/m3. Some ben- zo(a)pyrene contamination was found with particulates but only in five samples. Ammonia and ozone levels were negligible. TOBACCO-INDUCED POLLUTION IN TRANSPORTATION-RELATED ENCLOSURES As with domestic premises, tobacco smoke data for transportation-related en- closures such as cars, garages, buses, and trains, is spares. However, there are a few useful studies available. Automobiles In 1974, Harke et al. conducted two sets of experiments with cigarette- produced CO. In the first of these tests (1974b), a car was placed in a wind tunnel with four passengers, three of whom smoked cigarettes. Time spent smoking was varied, as was wind speed and ventilation. At 0 kmlhour, with full ventilation, CO averaged 8 to 10 ppm when six cigarettes were smoked intermittently. At 50 km/hour with no ventilation, and nine cigarettes smoked intermittently, CO reached 30 ppm. When cigarettes were smoked continuously, one after the other, final CO levels were registered at 80 ppm with no wind or ventilation factor. With ~A ~ TER~-` S~~ ~4~~`"~6

N K121'70098 EXPOSURE TO POLLUTANTS 15 wind and ventilation, however, CO remained at 5 to 6 ppm, with no increases observed. In all cases CO levels returned to base levels even with no ventilation, within a few minutes after smoking stopped. In the second set of tests (Harke, 1974a), cars of different makes were driven in Hamburg streets while being tested for CO. Cigarettes were smoked continuously by two of the four passengers. Each car made two runs per day with and without ventilation. At no ventilation, 21.4 ppm CO was registered on the average. With the air jets open, CO averaged 15.7 ppm, and with the blower also on, CO aver- aged 12.0 ppm. Speed was also an important factor. At 80 km/hour and with ventilation off, CO averaged 12.1 ppm, while at 35 km/hour CO reached 24.3 ppm. Unfortunately, Harke does not report background CO levels. Srch (1967) measured CO concentrations produced by cigarettes in a closed automobile with no ventilation present in or outside. The test car was parked in an unventilated garage while two smokers consumed five cigarettes each in 1 hour. CO levels reach 90 ppm in that time. COHb in smokers rose from 5 to 10%, and in the two non smokers present, from 2 to 5%. Buses The U. S. Department of Transportation in 1973 conducted a study of cigarette-caused pollution on intercity buses. Inside a stationary Greyhound bus with the engine off, vents open, and blower on, cigarettes were allowed to burn in the ashtrays. Test conditions ranged from the "worst" case, where it was as- sumed that all 43 passengers smoked half the time, to the "realistic" case, where only the last 20% of the seats were allotted to smokers. After 30 minutes in the worst case, CO stabilized at 33 ppm, and in the realistic case, CO stabilized at 18 ppm, after 43 minutes, with the outside level 13 ppm. Additional values obtained under normal operating conditions were provided by Hinds and First (1975). Nicotine concentration was found to be 6.3 AgJm3 on a commuter bus and 1.0 gg/m3 in a bus station waiting room. These values, how- ever, represent only a single case. Hinds and First also reported that passengers ignored smoking and nonsmoking zones indicated on the bus. As some sugges- tions have been made to segregate smokers and nonsmokers on buses, Hinds and First's observations raise the problem of how such segregations would be en- forced. Also, as Amiro (1967) had found CO values to be higher at the rear of the bus, a question is raised of how to distribute smokers and nonsmokers equitably. Trains Harmsen and Effenberger (1957) studied "dust" in nonsmoker and smoker cars. Dust values in smoker cars ranged from 100 to 200 particles/cm3 of air, and from 21 to 63 particles/cm3 in nonsmoker cars. The numbers of cigarettes were not specified. Unfortunately it was not reported whether the numbers of passengers were different in the two types of car. CO and nicotine were then surveyed on the same trains. CO ranged from 0 in nonsmoker cars, up to 40 ppm in heavily smoked cars. Nicotine ranged from 0.7 mg/1000 liters with light smoking to 3.1 mg/1000 liters with heavy smoking. The method of CO measurement (Draeger tube) used in this study, however, is not a very accurate one, and has a wide margin of error (±25%). This applies to the nicotine assay method (wet method) as well. Hinds and First (1975) reported nicotine concentrations of a much lower level. ER-SPT 003897

16 STERLING AND KOBAYASHI NKO21'74099 Their measurements on a commuter train averaged 4.9µg/m3. This was calculated as a smoking equivalent of 0.004 cigarettes/hour. Ferryboat There is one report of tobacco-induced pollution on a ferryboat. Both smoking and nonsmoking sections were tested for CO concentrations by Godin et at. (1972). Carbon monoxide averaged 18.4 ± 8.7 ppm in the smoking compartment and 3.0 ± 2.4 ppm in the nonsmoking section. (Unfortunately important informa- tion was not included as, for example, proximity to the engine room. It is difficult in this case to determine emission sources precisely.) Airplanes In response to public inquiry into tobacco smoke pollution in aircraft, the U.S. Department of Transportation in conjunction with the Federal Aviation Adminis- tration and NIOSH undertook a study of military and domestic flights. All smoke constituents were found to be extremely low due to ventilation. CO averaged 2 ppm while aldehydes and volatile hydrocarbons could not be detected. Particu- lates ranged up to 120µg/m3. In addition to testing for nicotine concentrations aboard aircraft, Hinds and First (1975) tested an airplane waiting room for nicotine and found 3.1 Ag/m3 and a cigarette equivalent of 0.003/hour. DfSCUSSION AND SUMMARY It has been assumed, somewhat naively, that exposure to toxic pollutants is limited largely to the air outside buildings and inside industrial shops. However, in the few studies in which pollutants were studied inside homes, schools, public buildings, and public places of assembly, the findings showed persisting higher levels of some pollutants inside these structures than outside. Even in transporta- tion vehicles, pollution tends to be higher inside than outside. We have sum- marized our findings in a number of tables for the different types of enclosed spaces for different communities in different studies and for different pollutants (see the Appendix). The results of all these studies consistently and dramatically point to an increase of exposure in the enclosed space. As we tend to spend most of our time either at home or in some public building, or traveling between one building or another, we are constantly exposed to levels of toxic materials which exceed the same levels measured on the outside. The reason is not hard to find. An enclosed space tends to entrap pollutants seeping in from outside. Additional pollutants are produced (and concentrated) in the en- closed space by crowding, by a large number of machines (some of which are designed to remove pollutants), by the activity of people, and by materials present and their decay over time. In artificially closed spaces the air is constantly cleaned by a number of anti pollution devices. Concentrations reported are of pollutant levels that exist during the operation of these air-cleaning devices. Without constant air cleaning, it would not be possible for man to survive in sealed spaces. On the other hand, most domestic enclosures, office buildings, and public places of assembly do not have the complex filtering and screening procedures to eliminate pollutants that enter from outdoors and, much less, to remove all the various pollutants generated ~ASTER-~~PP 00~~~~

H K®217 0 10 0 EXPOSURE TO POLLUTANTS 17 indoors. Ventilation through doors, windows, cracks, and crevices is the sole avenue for the elimination of toxic contaminants. It is not surprising, therefore, to find that the air in homes and other areas of human habitation sometimes exceeds exposure levels to toxic materials found in submarines and space craft. It has yet to be recognized that the dangers of contaminants in sealed environments also apply to partially sealed domestic premises and especially to the modern office- building type of structure. This is especially true because the many sources of pollution isolated in artificially sealed environments are present in the home and in public buildings. Significant, too, is the enrichment of particles in the house. Particles such as soot and fibers offer surfaces to which may adhere any number of chemicals. Many of these chemicals may be toxic. One frequent source of such toxic mate- rials is the industrially employed adult who may carry home dusts containing harmful substances such as beryllium and asbestos on his clothing, hair, or skin. (For instances of familial disease see Lieben and Williams (1969) and Anderson (1976).) There are many other sources, generated both within and without a build- ing. Many of the pollutants result from the combustion of coal and petroleum. Much of this benzene-soluble organic matter that adheres to and is found in heightened concentrations on particles breathed in the home is basically car- cinogenic. The longer the particles remain in a home, the more they may become . concentrators of toxic matter. When such particles become lodged in the lungs, they may be much more harmful than particles found in the outside air. In fact, , the incidence of so-called familial occupational disease may be related to this process of particle enrichment. High levels of CO resulting from cooking should be of considerable concern. Apparently CO levels of 200 to 300 ppm are not unlikely to occur in poorly ventilated homes, and the extremely high levels of CO (as found in Nigerian and New Guinea homes) may very likely occur also in homes in North America. This is especially so in the homes of the poor, where good ventilation is not likely to be found. Great concern has been expressed recently that tobacco smoke is a major source of pollution in the home and in public buildings (Schmeltz et al. (1975) and Rylander (1974), for instance.) Our review of data has therefore taken special notice of studies that have measured levels of tobacco-related pollutants. Unfor- tunately, many of the studies measuring dust or CO in the smoker's environment innocently assume zero levels of these contaminants in the absence of smoke so that the addition of smoking to the overall pollution can be assessed only approx- imately. Fortunately, it has now been shown that CO values in buildings and the associated COHb levels and the contributions of smoking to these levels can be estimated with great accuracy. Where conditions of ventilation and other parameters are known, contributions of cigarette emissions to CO and COHb levels were predicted with good accuracy by Jones and Fagan (1974, 1975). This was accomplished by applying to the by now well-tested equation developed by Turk and another equation for COHb levels by Pace (1946), data from Anderson and Dalhamn (1973), Lefcoe and Inculet (1971), and the Department of Transportation surveys of aircraft (1971) and buses (1973). With poor ventilation, it appears that ~AC5TER-C5PP 003899

18 STERLING AND KOB:1l'ASHI HK O2 17u1a 1 smoking adds to the body burden, but not extensively. For instance, CO values in average-sized public rooms and under average conditions of ventilation appear to be increased by 7 to 9 ppm when smoking is permitted in them (Bridge and Corn. 1972). Similarly, the amount of nicotine found in the air of public places ranges between 0.001 and 0.011 filter-cigarette equivalents per hour (Hinds and First, 1975). It is clear that while smoking adds to overall pollutant levels, it is only one other, and a relatively minor, source of pollution. SOME UNPLEASANT CONCLUSIONS ABOUT POLLUTANT BURDENS IN PUBLIC BUILDINGS As with domestic structures, many sources of indoor contamination found in submarines are also likely to be found in public buildings. Yet, the increasing use of steel and glass structures suggests a number of serious problems. As in all sealed structures, the escape rate of contaminants is seriously impeded and pol- lutants may easily build up inside. It may be possible that many of the undesirable features of completely enclosed structures, such as submarines, actually are amplified by the characteristics of public buildings. Also, the special antipollution devices which submarines carry are conspicuously absent in office and public buildings. In general, public buildings have no way of removing CO, C02, hy- drocarbons, lead, ammonia, oxides of nitrogen, oxidants, and other pollutants pres- ent in the outer air and likely found indoors as well. The more airtight a structure is, the longer it can trap contaminants inside. As Schulte (1964) points out, pollut- ant concentrations in submarines rise very rapidly when the CO burners, CO2' scrubbers, electrostatic precipitators, inert filters, activated beds, etc., are not operating. Usually there are no similar air-cleansing mechanisms in public struc- • tures. Present studies appear to show that indoor pollution in public office buildings is of greater potential harm than outdoor pollution. Air-conditioned and modern enclosed buildings are penetrable, sometimes highly penetrable, by nearly all forms of outdoor pollution. Even with filtration and pollutant-removal devices, there is a great possibility that pollutants will be trapped inside and will lead to continuous exposure at high levels. With a significant increase in outside pollution to be expected in cities as we turn increasingly toward cheaper fuels, these expo- sures may constitute a real threat to the health of a large part of the urban popula- tion. t ' This threat may be infinitely aggravated during energy crises, when the action of ventilation equipment and antipollution devices will be curtailed, according to recent suggestions by the American Society of Heating, Refrigeration, and Air Conditioning Engineers (1975). MASTER-SPP 0039-AGNO

TABLE I PA RTIC ULATES z Source Location Biersteker el al., 1965 Domestic premises (N = 60) Cleary and Blackburn, 1968 Domestic premises Jacobs et al.. 1962 Domestic premises Lefcoe and Inculet, 1971, 1975 Domestic premises Schaefer ct al.. 1972 Yocom, 1971a,b DeRouane, 1971 Jacobs et a!„ 1962 Japan Air Cleaning Assoc., 1968 Hunt and Cadotl, 1971 Matsumoto and Kitamura, 1971° Yocom, 1971a,b Ayres et al., 1973 Larsen and Konopinski, 1962 Waller et a1., 1961 Mean value 157.72 14g/m'" 666 µg(ms Not given (1022.79)•(10'/ft') (filter off), (406.66),(10'/ft') (filter on)P Domestic premises (N = 100) Not given Domestic premises (N = 2) Buildings Buildings Buildings Buildings Buildings Buildings Tunnels Tunnels Tunnels Matsumoto and Kitamura, 1971 Subways ° Derived from tables. ° Department stores, cinema, tearoom, bowling alley. Not given Range 52-309 µg/m° Peak = 4862 µg/m' 1.7-34.9 mp/ft' (139.3-1584.28) •(l0'/ft') 4.5-9 mg (mass/foiq residential areas 9 to >18 mg (mass/foi) cities 32-76 µg/ma 38 and 45 µg/m' Up to 300 µg/m° Not given 4-53.4 mg/fN Not given Not given Not given Not given Not given 0.22-2.04 mg/m' Not given 22-107 µg/ma 200 µg/ma 600 µg/m3 Not given 1.28 mg/m' Not given Not given 93 -235 µg/IOOm' 0.43-2.43 mg/m' Comments Indoor = 80% of outdoor More fibers found indoors Outdoor higher than indoor Indoor level less than outdoor 77.5-84.9% of outdoor level Smaller particles indoors Filters reduce particles "significantly" Lower levels indoors Double outdoor values "severe" dust Lower levels indoors Six times outside levels ISi times outside levels

TABLE 2 SOILING INDEX Source Location Mean value Range Comments Yocom, i971a,b Domestic premises Not given 0.22-0.52 Cohs/1000 ft Yocom, 1971a,b Buildings Not given 0.19-0.61 Cohs/1000 ft Larsen and Konopinski, 1962 Tunnels 4.25 Cohs/1000 ft Not given 0.53 Cohs/1000 ft (outdoors) TABLE 3 CARBON MONOXIDE Source * Location Mean value (ppm) Range (ppm) Comments Amiro, 1969 Domestic premises Not given 200-300 9017o of homes tested, (N = 300) (selected cases) CO positive 1968 Cl d Bl kb 21 3 150 ( eak) eary an ac urn, Godin et al., 1972 Farm house Outdoor . 0.8 ±- 0.6 p Not given Indoor 1.0 ± 0.8 Not given Suburban home Outdoor 2.0 ±- 1.4 Not given Indoor 1.9 :L 1.3 Not given Goldsmith, 1970 Domestic Not given Not given 100,000 persons exposed/yr Kahn et al., 1974 Domestic Not given Not given in U.S. Winter indoor CO higher Sofoluwe, 1968 Domestic (N = 98) 940.2 100-3000 than outdoor Tanaka et al., 1971 Domestic Not given up to 290 Wade et al., 1975 (gas stove) Domestic Not given 4190-90704 Peaks occurred coincidental to operation (kitchen) of gas appliances Yates, 1967 (Gas stove) Not given 10-2500+ Referrals tested, 100% CO positive Yocom, 1971a,b Not given 1-5 ppm random sample tested, 33% CO positive Godin et al., 1972 Buildings ' Small Ist tloor, 2.2 t 1.3 Not given Outdoor = 2.7 t 1.5 ppm Tall 2nd floor, 2.8 -t 1.5 Ist floor, 4.6 Not given Not given Outdoor = 6.4 ppm 54th floor, 2.4 Not given N c