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Health and environmental effects of open burning
Burning waste materials in burn barrels
Pollutants from burn barrels vary depending on the type of waste materials burned but, typically, emissions include dioxins, ash, furans, halogenated hydrocarbons, carbon monoxide, lead, barium, chromium, cadmium, carbon dioxide, sulfur dioxide, arsenic or mercury. Burn barrels also often emit acid vapors and carcinogenic tars.
Pound for pound, garbage burned in a burn barrel gives off twice as many furans, 17 times as much dioxin, and 40 times as much ash as a municipal incinerator. For example, a 1997 EPA study showed that two-to-40 households burning garbage produce as much dioxin as a 200 ton/day municipal incinerator operating with air pollution controls. Also, municipal incinerators operate at 2,200 degrees F to insure complete combustion, and they use efficient filters to reduce harmful emissions.
Burn barrels emit more pollutants because they operate at relatively low temperatures (400-500 degrees F), resulting in incomplete combustion of the wastes being burned. They also are less efficient at combustion and emissions are concentrated close to the ground, thus creating a greater risk of direct exposure to harmful pollutants. The closer you stand to the burn barrel, the more of these harmful chemicals you may inhale.
Residual ash is another result of incomplete combustion. Frequently, a significant portion of material in the barrel - especially at the bottom - is not burned up. Ash disposal outside of a sanitary landfill can cause problems.
Also, ash particulates can irritate the eyes and throat and can restrict visibility. In addition, ash can damage the lungs, cause bronchitis, emphysema, and lung cancer, and can seriously affect people with asthma or certain allergies. Ash also contains heavy metals that may seep into groundwater.
Burning leaf and yard waste
The smoke generated by a large number of simultaneous leaf fires can cause significant health problems. Leaf smoke can irritate the eyes, nose and throat of healthy adults. But it can be much more harmful to small children, the elderly, and people with asthma or other lung or heart diseases. This is because the visible smoke from leaf fires is made up almost entirely of tiny particles that can reach deep into lung tissue and cause symptoms such as coughing, wheezing, chest pain and shortness of breath—symptoms that might not occur until several days after exposure to large amounts of leaf smoke.
Besides being an irritant, leaf smoke contains many hazardous chemicals, including carbon monoxide and benzo(a)pyrene. Carbon monoxide binds with hemoglobin in the bloodstream and, thus, reduces the amount of oxygen in the blood and lungs. It can be especially dangerous for young children with immature lungs, smokers, the elderly, and people with chronic heart or lung diseases.
Benzo(a)pyrene is known to cause cancer in animals and is believed to be a major factor in lung cancer caused by cigarette smoke. It is found in cigarette smoke and coal tar, as well as in leaf smoke.
According to EPA studies, concentrations of air pollutants resulting from leaf burning can sometimes be so high that the air does not meet federal air quality standards. In fact, the burning of leaves and brush in some areas may at times cause much higher levels of air pollution than all other forms of air pollution combined (such as factories, vehicles, and lawn and garden equipment).
Leaf burning also can reduce visibility, create safety hazards, cause a nuisance, soil buildings and other property, and create additional demands on local police and fire protection resources.
Even though leaf burning may be legal in many localities, it is not a good way to dispose of fallen leaves. Instead of burning your leaves, you can:
- compost leaves and plant clippings. You can reduce the volume of leaves significantly by shredding them before composting;
- chip brush and clean wood to make mulch or decorative chips; and
- use municipal collection services if available, or ask your local municipality to offer such a service or a drop-off center.
- Backyard burning identified as major source of dioxins
- Human health hazards - trash and wood burning - Wisconsin Dept. of Health Services
- Backyard burning - U.S. EPA
Burning agricultural plastics
As with all plastics and other garbage, burning plastic film and containers used on farms and in greenhouses and landscaping is harmful to human health and the environment. Plastic should instead be recycled when possible and sent to the landfill if no recycling options are available.
The term "agricultural plastics" (or "ag plastics") covers a wide variety of products and plastic types. These include:
- low density polyethylene (LDPE and LLDPE) film used to make silage and hayage bags, bunker silo covers, greenhouse covers, bale wrap, mulch film and other flexible products;
- high density polyethylene (HDPE), a more rigid plastic used in pesticide containers and nursery pots;
- polystyrene (PS), another rigid plastic used in nursery containers and flats; and
- polypropylene (PP), used in nursery pots, row covers and woven tarps.
Burning any type of plastic releases toxic and potentially cancer-causing chemicals into the air, where they can be inhaled by humans and animals and deposited in soil and surface water and on plants. Residue from burning contaminates the soil and groundwater and can enter the human food chain through crops and livestock. In addition, certain chemicals released by burning can accumulate in the fats of animals and then in humans as we consume meat, fish and dairy products. Because agricultural burning often occurs near food sources, it is particularly important to reduce this health hazard to food production.
Some of the most dangerous chemicals created and released during burning some types of plastic are dioxins, which are byproducts formed when chlorine-containing products are burned, tend to adhere to the waxy surface of leaves and then enter the food chain. Even if certain types of plastic (such as polyethylene or polypropylene) do not contain chlorine, other materials attached to or burned with the plastic may be a chlorine source.
Other chemicals released while burning plastics include benzo(a)pyrene (BAP) and other polyaromatic hydrocarbons (PAHs), which have both been shown to cause cancer. If film or containers are contaminated with pesticides or other harmful substances, those will also be released into the air. If plastics are burned with other materials, additional toxic chemicals may be created from the interaction of the different substances.
Unburned portions of the plastic become litter on the ground and in lakes and rivers. As it disintegrates, animals may eat the plastic and get sick. Larger pieces of plastic can become a breeding ground for diseases, such as by trapping water that provides habitat for mosquitoes.