Benzene, naphthalene, styrene, tol- and ash were: Figures 4, 5, and 6 compare the uene, and xylene are aromatic hydrocar- • A broken fiberglass spinning rod garbage items that released more than two bons, which are suspected carcinogens. • A combination of cigarette and candy times as much benzene, styrene, and Aromatic hydrocarbons also are severe wrappers xylene as wood. Benzene, styrene, and eye, nose, and throat irritants. These • Nickel-cadmium batteries xylene are common air pollutants pro- compounds occur in petroleum products • Alkaline and lithium batteries duced by burning plastic. and automobile exhaust. They also are found in dyes and are used to produce a number of organic compounds. Benzene Relative amount of benzene in smoke is a major component in tobacco smoke. 0 10 20 30 Naphthalene is an ingredient in moth- Wood balls. Toluene and xylene occur in petro- Plastic (No. 6) packaging leum products and in dyes. Styrene is Plastic (No. 1) packaging Styrofoam cups primarily used in the production of poly- Alkaline and lithium batteries styrene plastics and resins. Meal-Ready-to-Eat packaging Benzene Acrolein and acetaldehyde are alde- Nickel-cadmium batteries hydes. Aldehydes are used for making Peanut can with plastic lid dyes, resins, and plastics. Acrolein is Plastic bags toxic to aquatic organisms and acetal- Plastic grocery bags dehyde has been proven to cause cancer Aluminum pop can in animals. Studies have not proven Plastic (No. B2) plate whether these compounds cause cancer in humans. Figure 4—The amount of benzene—a suspected carcinogen—in a campfireʼs smoke increased, Furan is on the U.S. Environmental sometimes dramatically, when garbage items were added to the wood fire. Protection Agencyʼs list of extremely haz- ardous substances. Furan is released into the air during incomplete combustion. It Relative amount of styrene emits acrid smoke and irritating fumes. in smoke 0 40 80 120 160 Ash—The ash samples were ana- Wood lyzed for 29 inorganic elements. The ash Plastic (No. 6) packaging from campfires that just burned wood Plastic (No. 1) bottles Diaper had high concentrations of barium (Ba), Snack-size chip bags calcium (Ca), potassium (K), magnesium Alkaline and lithium batteries (Mg), and sulfur (S). The concentrations Spinning rod with line Meal-Ready-to-Eat packaging of highly toxic elements such as cadmi- Miscellaneous tape Styrene um (Cd) and mercury (Hg) were barely Plastic (No. 4) tray within the detection limits of the instru- Nickel-cadmium batteries Aluminum foil ment used to analyze the ash from camp- Plastic bags fires that just burned wood. Plastic grocery bags Plastic and foil packaging Aluminum pop can Campfires with Wood Plastic (No. B2) plate and Garbage Smoke—The four products that Figure 5—The amount of styrene—a suspected carcinogen—in a campfireʼs smoke increased, released high levels of toxins in smoke sometimes dramatically, when garbage items were added to the wood fire. 4 Burning plastic bags released large Relative amount of xylene in smoke amounts of acrolein. Other products that 0 40 80 120 Wood released acrolein were styrofoam cups Plastic (No. 1) bottles and alkaline and lithium batteries (fig- Diaper ure 9). Cigarette and candy wrappers When plastic bags were burned in Snack-size chip bags a campfire, furan emissions were seven Alkaline and lithium batteries Spinning rod with line times higher than emissions from camp- Meal-Ready-to-Eat packaging Xylene fires that just burned wood (figure 10). Miscellaneous tape Campfires burning nickel-cadmium Nickel-cadmium batteries batteries and aluminum foil released more Hard plastic container Plastic bags than four times as much naphthalene as Plastic grocery bags campfires that just burned wood (figure Plastic and foil packaging 11). Aluminum pop can Ash—Many elemental metals occur Plastic (No. 2) plate naturally in the Earthʼs crust and in rocks. Small amounts of many of these metals Figure 6—The amount of xylene—a suspected carcinogen—in a campfireʼs smoke increased, are necessary to support life. But in larger sometimes dramatically, when garbage items were added to the wood fire. amounts, they may be toxic. Several elemental metals that can Toluene is abundant in the smoke of burned four different garbage items re- be toxic to humans, animals, and plants campfires that just burn wood. Only nick- leased large amounts of acetaldehyde were detected at elevated levels in camp- (figure 8). The garbage items were: fires that burned garbage. They were el-cadmium batteries (figure 7) released more toluene in smoke than wood. The fire was not large or hot enough to burn Relative amount of the batteries completely. If the batteries acetaldehyde in smoke 0 20 40 60 80 had been burned in a hotter fire, they Wood could have released more chemical Plastic (No. 1) bottles compounds. Snack-size chip bags Acetaldehyde Styrofoam cups Relative amount of toluene in smoke Alakaline and lithium batteries 0 1 2 Wood Nickel-cadmium Toluene batteries Figure 8—Compared to several garbage items, wood releases just a small amount of acetaldehyde when it is burned in a campfire. Acetaldehyde causes cancer in animals. Figure 7—Nickel-cadmium batteries were the only garbage item that released more of the toxin • Alkaline and lithium batteries • Cadmium • Lead toluene—a suspected carcinogen—than wood • Styrofoam cups • Beryllium • Mercury when burned in a campfire. • Snack-size chip bags Cadmium dust is carcinogenic to Only a small amount of acetalde- • Clear plastic pop bottles humans and animals. Cadmium is used hyde was released from campfires that Acrolein is a major air pollutant and in batteries and dyes. High levels were just burned wood, but campfires that is a severe irritant to the eyes and nose. detected in the ash from campfires that 5 campfires that burned nickel-cadmium, Relative amount of acrolein (2-propenal) in smoke alkaline, and lithium batteries (figure 13). 0 1 2 3 4 5 6 7 8 9 Lead is a suspected carcinogen and Wood may affect the lungs and kidneys. Small Styrofoam cups Acrolein amounts are present naturally in certain Alakaline and lithium batteries (2-propenal) soils. Lead is used in storage batteries Plastic bags and for pigments in paint. A small amount of lead was detected in the ash from campfires that just burned wood. Figure 9—Very high amounts of the air pollutant acrolein (2-propenal) were released when plastic However, almost 10 times more lead was bags were burned in a campfire. Acrolein is toxic to aquatic organisms. detected in the ash from the campfire that burned a broken fiberglass spinning Relative amount of furan rod. Additional garbage items that left in smoke 0 1 2 3 4 5 6 7 8 elevated amounts of lead in the ash (fig- Wood ure 14) were: • Plastic bags Furan Nickel-cadmium batteries • Packaging for freeze-dried meals • Plastic forks and spoons • Figure 10—Emissions of furan were seven times as high when plastic bags were burned in a campfire Snack-size chip bags than when the campfire just burned wood. Furan is on the U.S. Environmental Protection Agencyʼs • White plastic lids for disposable hot list of extremely hazardous stubstances. beverage cups Exposure to high levels of mercury Relative amount of naphthalene in smoke results in permanent nervous system and 0 1 2 3 4 5 6 7 8 9 10 kidney damage. Mercury levels were Wood barely detectable in the ash from camp- Nickel-cadmium batteries Naphthalene fires that just burned wood. The only Aluminum foil garbage items that left more than three times as much mercury in the ash were cigarette and candy wrappers. Figure 11—Campfires burning nickel-cadmium batteries and aluminum foil released much more naphthalene—a suspected carcinogen—than campfires that just burned wood. burned nickel-cadmium batteries and in Relative amount of cadmium smaller amounts from campfires that in ash 0 400 800 1200 1600 burned a colored cardboard box and Wood alkaline and lithium batteries (figure 12). Colored cardboard box Although there is only limited evi- Cadmium dence that beryllium causes cancer in Alkaline and lithium batteries humans, there is evidence that it causes Nickel-cadmium batteries cancer in animals. Beryllium levels were barely detectable in the ash from camp- fires that just burned wood. High levels Figure 12—Nickel-cadmium batteries, colored cardboard, and alkaline and lithium batteries left higher levels of cadmium in the ash than did a campfire that just burned wood. Cadmium dust is of beryllium were detected in the ash of carcinogenic to humans and animals. 6 This study was performed to simu- Relative amount of beryllium in ash late a campfire. The amount of pollutant 0 20 40 60 80 produced by wood fires changes as the Wood fires burn. A study conducted under Nickel-cadmium batteries Beryllium controlled conditions that took the com- Alkaline and lithium batteries bustion efficiencies of different fuels into account could produce different results than those of this informal study. Figure 13—Ash from a campfire that burned nickel-cadmium and alkaline and lithium batteries had high levels of beryllium, which causes cancer in animals. Beryllium levels were barely detectable in The common-sense summary of the the ash when the campfire just burned wood. results of this study is: Do not burn garbage in a campfire! Pack it in, pack Relative amount of lead it out. in ash 0 2 4 6 8 Wood Acknowledgments Nickel-cadmium batteries I would like to thank Dr. Ron Susott, Ron Babbitt, Sherri Dingley, and Steve Alkaline and lithium batteries Baker of the Rocky Mountain Research Spinning rod with line Stationʼs fire chemistry project in Mis- Lead soula, MT, for peer review and for con- Packaging for freeze-dried meals tributing their research knowledge of fire chemistry; Sherri Dingley for collecting Plastic hot-beverage cup lids and analyzing the gas samples; Tony Plastic forks and spoons Ward of the University of Montanaʼs Center for Environmental Health Sci- Snack-size chip bags ences for his review and expertise with toxins that are hazardous to human health; and Lori Messenger, smokejumper, for Figure 14—Some garbage items left elevated levels of lead—a suspected carcinogen—in the ash compared to a campfire that just burned wood.