Used tyres represent a serious environmental concern on several fronts. Toxins released from tyre decomposition, incineration or accidental fires can pollute the water, air and soil. One of the simplest ways to reduce the used tyre disposal problem is to retread tyres.

The biggest problem with discarding old tyres is that they contain chemicals and heavy metals that leach into the environment as the tyres break down. Some of these chemicals, according to the California Integrated Waste Management Board, are carcinogenic and mutagenic (cause cancer and gene mutations).Leaching affects the soil around the old tyre, which at first may not seem like a big problem. But if the tyre is eventually moved, the soil will still have the toxins. Another major concern is groundwater. If toxins get into any water in the soil, the water can transport them to other locations, potentially harmful to any animals that come in contact with the poisoned water.

The hollow middle of a tyre will easily fill up with rainwater if the tyre is just left out in the open. If the tyre is left undisturbed, the water will remain in the tyre and become a breeding ground for insects such as mosquitoes. The mosquitoes then go about spreading diseases to humans and animals.

The risk of fire is another potential danger and environmental hazard related to tyre dumps. Tyre fires burn very hot and are extremely difficult to extinguish. Also, in the extreme heat of the fire, tyres can melt into an oily substance. When the fire is doused this substance mixes with water to form a harmful run-off that can contaminate surface water sources nearby. Even if tyres aren’t being sent to tyre burning disposal facilities, they still pose a fire threat. Fires fuelled by tyre material are harder to control and extinguish than regular fires. If tyres are discarded rather than recycled, they could combust, release their carcinogens into the air, and start a destructive fire.