Burning trash in the open produces many pollutants, including:
- particle pollution,
- polycyclic aromatic hydrocarbons,
- volatile organic compounds,
- carbon monoxide,
- hexachlorobenzene, and
Many dangerous health conditions can be caused by inhaling or ingesting even small amounts of these pollutants. Small children, the elderly, or people with preexisting respiratory conditions can be especially vulnerable to some of these pollutants.
DioxinsBackyard burning is of particular health concern because it produces significant quantities of dioxins. Dioxins and "dioxin like" compounds are a group of 30 highly toxic chlorinated organic chemicals. They are produced naturally in small quantities, but are primarily the result of human activity. They can be produced through industrial processes such as chlorinated chemical manufacturing and metal smelting. Currently, however, the largest quantified source of dioxin emissions is the uncontrolled burning of household trash (backyard burning). Studies have shown that only small amounts of chlorinated materials in waste are required to support dioxin formation when burning waste. This means that even when materials containing high levels of chlorine, such as PVC, are removed from household trash, burning the waste still creates dioxins because nearly all household waste contains trace amounts of chlorine.
Much of the dioxins created and released into the air through backyard burning settle on plants. These plants are, in turn, eaten by meat and dairy animals, which store the dioxins in their fatty tissue. People are exposed to dioxins primarily by eating meat, fish, and dairy products, especially those high in fat. Backyard burning occurs most commonly in rural farming areas where dioxin emissions can more easily be deposited on animal feed crops and grazing lands. These dioxins then accumulate in the fats of dairy cows, beef, poultry, and swine, making human consumption of these harmful chemicals difficult to avoid.
Dioxins are classified as persistent, bioaccumulative, and toxic pollutants (PBTs). PBTs are highly toxic, long-lasting substances that can build up in the food chain to levels that are harmful to human and ecosystem health. Persistent means they remain in the environment for extended periods of time. Bioaccumulative means their concentration levels increase as they move up the food chain. As a consequence, animals at the top of the food chain (such as humans) tend to have the highest dioxin concentrations in their bodies.
Dioxins are potent toxicants with the potential to produce a broad spectrum of adverse effects in humans. Dioxins can alter the fundamental growth and development of cells in ways that have the potential to lead to many kinds of impacts. These include adverse effects upon reproduction and development, suppression of the immune system, disruption of hormonal systems, and cancer. For more detailed information on dioxin health effects, safety issues, and risk, visit EPA's Dioxin and Related Compounds Web site.