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What's Burning in Your Campfire? Garbage In, Toxics Out

Campfires with Wood, but No Garbage

Smoke—Many hazardous air pollutants and toxic metals are known to be human carcinogens that may increase the incidence of cancer. Air pollutants may have other effects on human health that are more difficult to measure, such as immunological, neurological, reproductive, developmental, mutagenic, or respiratory effects.

The hazardous air pollutants we measured in campfire smoke that are known to adversely affect human health were: acrolein (2-propenal), acetaldehyde, benzene, furan, naphthalene, styrene, toluene, and xylene. We did not analyze the smoke for toxic metals.

Benzene, naphthalene, styrene, toluene, and xylene are aromatic hydrocarbons, which are suspected carcinogens. Aromatic hydrocarbons also are severe eye, nose, and throat irritants. These compounds occur in petroleum products and automobile exhaust. They also are found in dyes and are used to produce a number of organic compounds. Benzene is a major component in tobacco smoke. Naphthalene is an ingredient in mothballs. Toluene and xylene occur in petroleum products and in dyes. Styrene is primarily used in the production of polystyrene plastics and resins.

Acrolein and acetaldehyde are aldehydes. Aldehydes are used for making dyes, resins, and plastics. Acrolein is toxic to aquatic organisms and acetaldehyde has been proven to cause cancer in animals. Studies have not proven whether these compounds cause cancer in humans.

Furan is on the U.S. Environmental Protection Agency's list of extremely hazardous substances. Furan is released into the air during incomplete combustion. It emits acrid smoke and irritating fumes.

Ash—The ash samples were analyzed for 29 inorganic elements. The ash from campfires that just burned wood had high concentrations of barium (Ba), calcium (Ca), potassium (K), magnesium (Mg), and sulfur (S). The concentrations of highly toxic elements such as cadmium (Cd) and mercury (Hg) were barely within the detection limits of the instrument used to analyze the ash from campfires that just burned wood.

Campfires with Wood and Garbage

Smoke—The four products that released high levels of toxins in smoke and ash were:

• A broken fiberglass spinning rod
• A combination of cigarette and candy wrappers
• Nickel-cadmium batteries
• Alkaline and lithium batteries

Figures 4, 5, and 6 compare the garbage items that released more than two times as much benzene, styrene, and xylene as wood. Benzene, styrene, and xylene are common air pollutants produced by burning plastic.

Figure 4—The amount of benzene—a suspected carcinogen—in a
campfire's smoke increased, sometimes dramatically, when garbage items
were added to the wood fire.

Figure 5—The amount of styrene— a suspected carcinogen—in a
campfire's smoke increased, sometimes dramatically, when garbage items
were added to the wood fire.

Figure 6—The amount of xylene—a suspected carcinogen—in a
campfire's smoke increased, sometimes dramatically, when garbage items
were added to the wood fire.

Toluene is abundant in the smoke of campfires that just burn wood. Only nickel-cadmium batteries (figure 7) released more toluene in smoke than wood. The fire was not large or hot enough to burn the batteries completely. If the batteries had been burned in a hotter fire, they could have released more chemical compounds.

Figure 7—Nickel-cadmium batteries were the only garbage item that
released more of the toxin toluene—a suspected carcinogen—than wood when burned in a campfire.

Only a small amount of acetaldehyde was released from campfires that just burned wood, but campfires that burned four different garbage items released large amounts of acetaldehyde (figure 8). The garbage items were:

• Alkaline and lithium batteries
• Styrofoam cups
• Snack-size chip bags
• Clear plastic pop bottles

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.

Acrolein is a major air pollutant and is a severe irritant to the eyes and nose. Burning plastic bags released large amounts of acrolein. Other products that released acrolein were styrofoam cups and alkaline and lithium batteries (figure 9).

Figure 9—Very high amounts of the air pollutant acrolein (2-propenal) were
released when plastic bags were burned in a campfire. Acrolein is toxic to aquatic organisms.

When plastic bags were burned in a campfire, furan emissions were seven times higher than emissions from campfires that just burned wood (figure 10).

Figure 10—Emissions of furan were seven times as high when plastic bags
were burned in a campfire than when the campfire just burned wood.
Furan is on the U.S. Environmental Protection Agency's list of extremely hazardous substances.

Campfires burning nickel-cadmium batteries and aluminum foil released more than four times as much naphthalene as campfires that just burned wood (figure 11).

Figure 11—Campfires burning nickel-cadmium batteries and aluminum foil
released much more naphthalene—a suspected carcinogen—than
campfires that just burned wood.

Ash—Many elemental metals occur naturally in the Earth's crust and in rocks. Small amounts of many of these metals are necessary to support life. But in larger amounts, they may be toxic.

Several elemental metals that can be toxic to humans, animals, and plants were detected at elevated levels in camp- fires that burned garbage. They were

• Cadmium
• Lead
• Beryllium
• Mercury

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